--- /dev/null
+++ b/Documentation/scheduler/sched-BFS.txt
@@ -0,0 +1,351 @@
+BFS - The Brain Fuck Scheduler by Con Kolivas.
+
+Goals.
+
+The goal of the Brain Fuck Scheduler, referred to as BFS from here on, is to
+completely do away with the complex designs of the past for the cpu process
+scheduler and instead implement one that is very simple in basic design.
+The main focus of BFS is to achieve excellent desktop interactivity and
+responsiveness without heuristics and tuning knobs that are difficult to
+understand, impossible to model and predict the effect of, and when tuned to
+one workload cause massive detriment to another.
+
+
+Design summary.
+
+BFS is best described as a single runqueue, O(n) lookup, earliest effective
+virtual deadline first design, loosely based on EEVDF (earliest eligible virtual
+deadline first) and my previous Staircase Deadline scheduler. Each component
+shall be described in order to understand the significance of, and reasoning for
+it. The codebase when the first stable version was released was approximately
+9000 lines less code than the existing mainline linux kernel scheduler (in
+2.6.31). This does not even take into account the removal of documentation and
+the cgroups code that is not used.
+
+Design reasoning.
+
+The single runqueue refers to the queued but not running processes for the
+entire system, regardless of the number of CPUs. The reason for going back to
+a single runqueue design is that once multiple runqueues are introduced,
+per-CPU or otherwise, there will be complex interactions as each runqueue will
+be responsible for the scheduling latency and fairness of the tasks only on its
+own runqueue, and to achieve fairness and low latency across multiple CPUs, any
+advantage in throughput of having CPU local tasks causes other disadvantages.
+This is due to requiring a very complex balancing system to at best achieve some
+semblance of fairness across CPUs and can only maintain relatively low latency
+for tasks bound to the same CPUs, not across them. To increase said fairness
+and latency across CPUs, the advantage of local runqueue locking, which makes
+for better scalability, is lost due to having to grab multiple locks.
+
+A significant feature of BFS is that all accounting is done purely based on CPU
+used and nowhere is sleep time used in any way to determine entitlement or
+interactivity. Interactivity "estimators" that use some kind of sleep/run
+algorithm are doomed to fail to detect all interactive tasks, and to falsely tag
+tasks that aren't interactive as being so. The reason for this is that it is
+close to impossible to determine that when a task is sleeping, whether it is
+doing it voluntarily, as in a userspace application waiting for input in the
+form of a mouse click or otherwise, or involuntarily, because it is waiting for
+another thread, process, I/O, kernel activity or whatever. Thus, such an
+estimator will introduce corner cases, and more heuristics will be required to
+cope with those corner cases, introducing more corner cases and failed
+interactivity detection and so on. Interactivity in BFS is built into the design
+by virtue of the fact that tasks that are waking up have not used up their quota
+of CPU time, and have earlier effective deadlines, thereby making it very likely
+they will preempt any CPU bound task of equivalent nice level. See below for
+more information on the virtual deadline mechanism. Even if they do not preempt
+a running task, because the rr interval is guaranteed to have a bound upper
+limit on how long a task will wait for, it will be scheduled within a timeframe
+that will not cause visible interface jitter.
+
+
+Design details.
+
+Task insertion.
+
+BFS inserts tasks into each relevant queue as an O(1) insertion into a double
+linked list. On insertion, *every* running queue is checked to see if the newly
+queued task can run on any idle queue, or preempt the lowest running task on the
+system. This is how the cross-CPU scheduling of BFS achieves significantly lower
+latency per extra CPU the system has. In this case the lookup is, in the worst
+case scenario, O(n) where n is the number of CPUs on the system.
+
+Data protection.
+
+BFS has one single lock protecting the process local data of every task in the
+global queue. Thus every insertion, removal and modification of task data in the
+global runqueue needs to grab the global lock. However, once a task is taken by
+a CPU, the CPU has its own local data copy of the running process' accounting
+information which only that CPU accesses and modifies (such as during a
+timer tick) thus allowing the accounting data to be updated lockless. Once a
+CPU has taken a task to run, it removes it from the global queue. Thus the
+global queue only ever has, at most,
+
+ (number of tasks requesting cpu time) - (number of logical CPUs) + 1
+
+tasks in the global queue. This value is relevant for the time taken to look up
+tasks during scheduling. This will increase if many tasks with CPU affinity set
+in their policy to limit which CPUs they're allowed to run on if they outnumber
+the number of CPUs. The +1 is because when rescheduling a task, the CPU's
+currently running task is put back on the queue. Lookup will be described after
+the virtual deadline mechanism is explained.
+
+Virtual deadline.
+
+The key to achieving low latency, scheduling fairness, and "nice level"
+distribution in BFS is entirely in the virtual deadline mechanism. The one
+tunable in BFS is the rr_interval, or "round robin interval". This is the
+maximum time two SCHED_OTHER (or SCHED_NORMAL, the common scheduling policy)
+tasks of the same nice level will be running for, or looking at it the other
+way around, the longest duration two tasks of the same nice level will be
+delayed for. When a task requests cpu time, it is given a quota (time_slice)
+equal to the rr_interval and a virtual deadline. The virtual deadline is
+offset from the current time in jiffies by this equation:
+
+ jiffies + (prio_ratio * rr_interval)
+
+The prio_ratio is determined as a ratio compared to the baseline of nice -20
+and increases by 10% per nice level. The deadline is a virtual one only in that
+no guarantee is placed that a task will actually be scheduled by this time, but
+it is used to compare which task should go next. There are three components to
+how a task is next chosen. First is time_slice expiration. If a task runs out
+of its time_slice, it is descheduled, the time_slice is refilled, and the
+deadline reset to that formula above. Second is sleep, where a task no longer
+is requesting CPU for whatever reason. The time_slice and deadline are _not_
+adjusted in this case and are just carried over for when the task is next
+scheduled. Third is preemption, and that is when a newly waking task is deemed
+higher priority than a currently running task on any cpu by virtue of the fact
+that it has an earlier virtual deadline than the currently running task. The
+earlier deadline is the key to which task is next chosen for the first and
+second cases. Once a task is descheduled, it is put back on the queue, and an
+O(n) lookup of all queued-but-not-running tasks is done to determine which has
+the earliest deadline and that task is chosen to receive CPU next.
+
+The CPU proportion of different nice tasks works out to be approximately the
+
+ (prio_ratio difference)^2
+
+The reason it is squared is that a task's deadline does not change while it is
+running unless it runs out of time_slice. Thus, even if the time actually
+passes the deadline of another task that is queued, it will not get CPU time
+unless the current running task deschedules, and the time "base" (jiffies) is
+constantly moving.
+
+Task lookup.
+
+BFS has 103 priority queues. 100 of these are dedicated to the static priority
+of realtime tasks, and the remaining 3 are, in order of best to worst priority,
+SCHED_ISO (isochronous), SCHED_NORMAL, and SCHED_IDLEPRIO (idle priority
+scheduling). When a task of these priorities is queued, a bitmap of running
+priorities is set showing which of these priorities has tasks waiting for CPU
+time. When a CPU is made to reschedule, the lookup for the next task to get
+CPU time is performed in the following way:
+
+First the bitmap is checked to see what static priority tasks are queued. If
+any realtime priorities are found, the corresponding queue is checked and the
+first task listed there is taken (provided CPU affinity is suitable) and lookup
+is complete. If the priority corresponds to a SCHED_ISO task, they are also
+taken in FIFO order (as they behave like SCHED_RR). If the priority corresponds
+to either SCHED_NORMAL or SCHED_IDLEPRIO, then the lookup becomes O(n). At this
+stage, every task in the runlist that corresponds to that priority is checked
+to see which has the earliest set deadline, and (provided it has suitable CPU
+affinity) it is taken off the runqueue and given the CPU. If a task has an
+expired deadline, it is taken and the rest of the lookup aborted (as they are
+chosen in FIFO order).
+
+Thus, the lookup is O(n) in the worst case only, where n is as described
+earlier, as tasks may be chosen before the whole task list is looked over.
+
+
+Scalability.
+
+The major limitations of BFS will be that of scalability, as the separate
+runqueue designs will have less lock contention as the number of CPUs rises.
+However they do not scale linearly even with separate runqueues as multiple
+runqueues will need to be locked concurrently on such designs to be able to
+achieve fair CPU balancing, to try and achieve some sort of nice-level fairness
+across CPUs, and to achieve low enough latency for tasks on a busy CPU when
+other CPUs would be more suited. BFS has the advantage that it requires no
+balancing algorithm whatsoever, as balancing occurs by proxy simply because
+all CPUs draw off the global runqueue, in priority and deadline order. Despite
+the fact that scalability is _not_ the prime concern of BFS, it both shows very
+good scalability to smaller numbers of CPUs and is likely a more scalable design
+at these numbers of CPUs.
+
+It also has some very low overhead scalability features built into the design
+when it has been deemed their overhead is so marginal that they're worth adding.
+The first is the local copy of the running process' data to the CPU it's running
+on to allow that data to be updated lockless where possible. Then there is
+deference paid to the last CPU a task was running on, by trying that CPU first
+when looking for an idle CPU to use the next time it's scheduled. Finally there
+is the notion of cache locality beyond the last running CPU. The sched_domains
+information is used to determine the relative virtual "cache distance" that
+other CPUs have from the last CPU a task was running on. CPUs with shared
+caches, such as SMT siblings, or multicore CPUs with shared caches, are treated
+as cache local. CPUs without shared caches are treated as not cache local, and
+CPUs on different NUMA nodes are treated as very distant. This "relative cache
+distance" is used by modifying the virtual deadline value when doing lookups.
+Effectively, the deadline is unaltered between "cache local" CPUs, doubled for
+"cache distant" CPUs, and quadrupled for "very distant" CPUs. The reasoning
+behind the doubling of deadlines is as follows. The real cost of migrating a
+task from one CPU to another is entirely dependant on the cache footprint of
+the task, how cache intensive the task is, how long it's been running on that
+CPU to take up the bulk of its cache, how big the CPU cache is, how fast and
+how layered the CPU cache is, how fast a context switch is... and so on. In
+other words, it's close to random in the real world where we do more than just
+one sole workload. The only thing we can be sure of is that it's not free. So
+BFS uses the principle that an idle CPU is a wasted CPU and utilising idle CPUs
+is more important than cache locality, and cache locality only plays a part
+after that. Doubling the effective deadline is based on the premise that the
+"cache local" CPUs will tend to work on the same tasks up to double the number
+of cache local CPUs, and once the workload is beyond that amount, it is likely
+that none of the tasks are cache warm anywhere anyway. The quadrupling for NUMA
+is a value I pulled out of my arse.
+
+When choosing an idle CPU for a waking task, the cache locality is determined
+according to where the task last ran and then idle CPUs are ranked from best
+to worst to choose the most suitable idle CPU based on cache locality, NUMA
+node locality and hyperthread sibling business. They are chosen in the
+following preference (if idle):
+
+* Same core, idle or busy cache, idle threads
+* Other core, same cache, idle or busy cache, idle threads.
+* Same node, other CPU, idle cache, idle threads.
+* Same node, other CPU, busy cache, idle threads.
+* Same core, busy threads.
+* Other core, same cache, busy threads.
+* Same node, other CPU, busy threads.
+* Other node, other CPU, idle cache, idle threads.
+* Other node, other CPU, busy cache, idle threads.
+* Other node, other CPU, busy threads.
+
+This shows the SMT or "hyperthread" awareness in the design as well which will
+choose a real idle core first before a logical SMT sibling which already has
+tasks on the physical CPU.
+
+Early benchmarking of BFS suggested scalability dropped off at the 16 CPU mark.
+However this benchmarking was performed on an earlier design that was far less
+scalable than the current one so it's hard to know how scalable it is in terms
+of both CPUs (due to the global runqueue) and heavily loaded machines (due to
+O(n) lookup) at this stage. Note that in terms of scalability, the number of
+_logical_ CPUs matters, not the number of _physical_ CPUs. Thus, a dual (2x)
+quad core (4X) hyperthreaded (2X) machine is effectively a 16X. Newer benchmark
+results are very promising indeed, without needing to tweak any knobs, features
+or options. Benchmark contributions are most welcome.
+
+
+Features
+
+As the initial prime target audience for BFS was the average desktop user, it
+was designed to not need tweaking, tuning or have features set to obtain benefit
+from it. Thus the number of knobs and features has been kept to an absolute
+minimum and should not require extra user input for the vast majority of cases.
+There are precisely 2 tunables, and 2 extra scheduling policies. The rr_interval
+and iso_cpu tunables, and the SCHED_ISO and SCHED_IDLEPRIO policies. In addition
+to this, BFS also uses sub-tick accounting. What BFS does _not_ now feature is
+support for CGROUPS. The average user should neither need to know what these
+are, nor should they need to be using them to have good desktop behaviour.
+
+rr_interval
+
+There is only one "scheduler" tunable, the round robin interval. This can be
+accessed in
+
+ /proc/sys/kernel/rr_interval
+
+The value is in milliseconds, and the default value is set to 6 on a
+uniprocessor machine, and automatically set to a progressively higher value on
+multiprocessor machines. The reasoning behind increasing the value on more CPUs
+is that the effective latency is decreased by virtue of there being more CPUs on
+BFS (for reasons explained above), and increasing the value allows for less
+cache contention and more throughput. Valid values are from 1 to 1000
+Decreasing the value will decrease latencies at the cost of decreasing
+throughput, while increasing it will improve throughput, but at the cost of
+worsening latencies. The accuracy of the rr interval is limited by HZ resolution
+of the kernel configuration. Thus, the worst case latencies are usually slightly
+higher than this actual value. The default value of 6 is not an arbitrary one.
+It is based on the fact that humans can detect jitter at approximately 7ms, so
+aiming for much lower latencies is pointless under most circumstances. It is
+worth noting this fact when comparing the latency performance of BFS to other
+schedulers. Worst case latencies being higher than 7ms are far worse than
+average latencies not being in the microsecond range.
+
+Isochronous scheduling.
+
+Isochronous scheduling is a unique scheduling policy designed to provide
+near-real-time performance to unprivileged (ie non-root) users without the
+ability to starve the machine indefinitely. Isochronous tasks (which means
+"same time") are set using, for example, the schedtool application like so:
+
+ schedtool -I -e amarok
+
+This will start the audio application "amarok" as SCHED_ISO. How SCHED_ISO works
+is that it has a priority level between true realtime tasks and SCHED_NORMAL
+which would allow them to preempt all normal tasks, in a SCHED_RR fashion (ie,
+if multiple SCHED_ISO tasks are running, they purely round robin at rr_interval
+rate). However if ISO tasks run for more than a tunable finite amount of time,
+they are then demoted back to SCHED_NORMAL scheduling. This finite amount of
+time is the percentage of _total CPU_ available across the machine, configurable
+as a percentage in the following "resource handling" tunable (as opposed to a
+scheduler tunable):
+
+ /proc/sys/kernel/iso_cpu
+
+and is set to 70% by default. It is calculated over a rolling 5 second average
+Because it is the total CPU available, it means that on a multi CPU machine, it
+is possible to have an ISO task running as realtime scheduling indefinitely on
+just one CPU, as the other CPUs will be available. Setting this to 100 is the
+equivalent of giving all users SCHED_RR access and setting it to 0 removes the
+ability to run any pseudo-realtime tasks.
+
+A feature of BFS is that it detects when an application tries to obtain a
+realtime policy (SCHED_RR or SCHED_FIFO) and the caller does not have the
+appropriate privileges to use those policies. When it detects this, it will
+give the task SCHED_ISO policy instead. Thus it is transparent to the user.
+Because some applications constantly set their policy as well as their nice
+level, there is potential for them to undo the override specified by the user
+on the command line of setting the policy to SCHED_ISO. To counter this, once
+a task has been set to SCHED_ISO policy, it needs superuser privileges to set
+it back to SCHED_NORMAL. This will ensure the task remains ISO and all child
+processes and threads will also inherit the ISO policy.
+
+Idleprio scheduling.
+
+Idleprio scheduling is a scheduling policy designed to give out CPU to a task
+_only_ when the CPU would be otherwise idle. The idea behind this is to allow
+ultra low priority tasks to be run in the background that have virtually no
+effect on the foreground tasks. This is ideally suited to distributed computing
+clients (like setiathome, folding, mprime etc) but can also be used to start
+a video encode or so on without any slowdown of other tasks. To avoid this
+policy from grabbing shared resources and holding them indefinitely, if it
+detects a state where the task is waiting on I/O, the machine is about to
+suspend to ram and so on, it will transiently schedule them as SCHED_NORMAL. As
+per the Isochronous task management, once a task has been scheduled as IDLEPRIO,
+it cannot be put back to SCHED_NORMAL without superuser privileges. Tasks can
+be set to start as SCHED_IDLEPRIO with the schedtool command like so:
+
+ schedtool -D -e ./mprime
+
+Subtick accounting.
+
+It is surprisingly difficult to get accurate CPU accounting, and in many cases,
+the accounting is done by simply determining what is happening at the precise
+moment a timer tick fires off. This becomes increasingly inaccurate as the
+timer tick frequency (HZ) is lowered. It is possible to create an application
+which uses almost 100% CPU, yet by being descheduled at the right time, records
+zero CPU usage. While the main problem with this is that there are possible
+security implications, it is also difficult to determine how much CPU a task
+really does use. BFS tries to use the sub-tick accounting from the TSC clock,
+where possible, to determine real CPU usage. This is not entirely reliable, but
+is far more likely to produce accurate CPU usage data than the existing designs
+and will not show tasks as consuming no CPU usage when they actually are. Thus,
+the amount of CPU reported as being used by BFS will more accurately represent
+how much CPU the task itself is using (as is shown for example by the 'time'
+application), so the reported values may be quite different to other schedulers.
+Values reported as the 'load' are more prone to problems with this design, but
+per process values are closer to real usage. When comparing throughput of BFS
+to other designs, it is important to compare the actual completed work in terms
+of total wall clock time taken and total work done, rather than the reported
+"cpu usage".
+
+
+Con Kolivas <kernel@kolivas.org> Fri Aug 27 2010
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -29,6 +29,7 @@ show up in /proc/sys/kernel:
- domainname
- hostname
- hotplug
+- iso_cpu
- java-appletviewer [ binfmt_java, obsolete ]
- java-interpreter [ binfmt_java, obsolete ]
- kstack_depth_to_print [ X86 only ]
@@ -51,6 +52,7 @@ show up in /proc/sys/kernel:
- randomize_va_space
- real-root-dev ==> Documentation/initrd.txt
- reboot-cmd [ SPARC only ]
+- rr_interval
- rtsig-max
- rtsig-nr
- sem
@@ -209,6 +211,16 @@ Default value is "/sbin/hotplug".
==============================================================
+iso_cpu: (BFS CPU scheduler only).
+
+This sets the percentage cpu that the unprivileged SCHED_ISO tasks can
+run effectively at realtime priority, averaged over a rolling five
+seconds over the -whole- system, meaning all cpus.
+
+Set to 70 (percent) by default.
+
+==============================================================
+
l2cr: (PPC only)
This flag controls the L2 cache of G3 processor boards. If
@@ -383,6 +395,20 @@ rebooting. ???
==============================================================
+rr_interval: (BFS CPU scheduler only)
+
+This is the smallest duration that any cpu process scheduling unit
+will run for. Increasing this value can increase throughput of cpu
+bound tasks substantially but at the expense of increased latencies
+overall. Conversely decreasing it will decrease average and maximum
+latencies but at the expense of throughput. This value is in
+milliseconds and the default value chosen depends on the number of
+cpus available at scheduler initialisation with a minimum of 6.
+
+Valid values are from 1-5000.
+
+==============================================================
+
rtsig-max & rtsig-nr:
The file rtsig-max can be used to tune the maximum number
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
VERSION = 2
PATCHLEVEL = 6
SUBLEVEL = 32
-EXTRAVERSION = .27
+EXTRAVERSION = .27-ck2
NAME = Man-Eating Seals of Antiquity
# *DOCUMENTATION*
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -63,11 +63,6 @@ static struct timer_list spusched_timer;
static struct timer_list spuloadavg_timer;
/*
- * Priority of a normal, non-rt, non-niced'd process (aka nice level 0).
- */
-#define NORMAL_PRIO 120
-
-/*
* Frequency of the spu scheduler tick. By default we do one SPU scheduler
* tick for every 10 CPU scheduler ticks.
*/
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1051,7 +1051,7 @@ endchoice
choice
depends on EXPERIMENTAL
- prompt "Memory split" if EMBEDDED
+ prompt "Memory split"
default VMSPLIT_3G
depends on X86_32
---help---
@@ -1071,17 +1071,17 @@ choice
option alone!
config VMSPLIT_3G
- bool "3G/1G user/kernel split"
+ bool "Default 896MB lowmem (3G/1G user/kernel split)"
config VMSPLIT_3G_OPT
depends on !X86_PAE
- bool "3G/1G user/kernel split (for full 1G low memory)"
+ bool "1GB lowmem (3G/1G user/kernel split)"
config VMSPLIT_2G
- bool "2G/2G user/kernel split"
+ bool "2GB lowmem (2G/2G user/kernel split)"
config VMSPLIT_2G_OPT
depends on !X86_PAE
- bool "2G/2G user/kernel split (for full 2G low memory)"
+ bool "2GB lowmem (2G/2G user/kernel split)"
config VMSPLIT_1G
- bool "1G/3G user/kernel split"
+ bool "3GB lowmem (1G/3G user/kernel split)"
endchoice
config PAGE_OFFSET
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -109,7 +109,7 @@ static int show_cpuinfo(struct seq_file
seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
c->loops_per_jiffy/(500000/HZ),
- (c->loops_per_jiffy/(5000/HZ)) % 100);
+ (c->loops_per_jiffy * 10 /(50000/HZ)) % 100);
#ifdef CONFIG_X86_64
if (c->x86_tlbsize > 0)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -481,7 +481,7 @@ static void impress_friends(void)
"Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
num_online_cpus(),
bogosum/(500000/HZ),
- (bogosum/(5000/HZ))%100);
+ (bogosum * 10/(50000/HZ))%100);
pr_debug("Before bogocount - setting activated=1.\n");
}
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -373,7 +373,7 @@ static int proc_pid_stack(struct seq_fil
static int proc_pid_schedstat(struct task_struct *task, char *buffer)
{
return sprintf(buffer, "%llu %llu %lu\n",
- (unsigned long long)task->se.sum_exec_runtime,
+ (unsigned long long)tsk_seruntime(task),
(unsigned long long)task->sched_info.run_delay,
task->sched_info.pcount);
}
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -119,6 +119,69 @@ extern struct cred init_cred;
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
*/
+#ifdef CONFIG_SCHED_BFS
+#define INIT_TASK(tsk) \
+{ \
+ .state = 0, \
+ .stack = &init_thread_info, \
+ .usage = ATOMIC_INIT(2), \
+ .flags = PF_KTHREAD, \
+ .lock_depth = -1, \
+ .prio = NORMAL_PRIO, \
+ .static_prio = MAX_PRIO-20, \
+ .normal_prio = NORMAL_PRIO, \
+ .deadline = 0, \
+ .policy = SCHED_NORMAL, \
+ .cpus_allowed = CPU_MASK_ALL, \
+ .mm = NULL, \
+ .active_mm = &init_mm, \
+ .run_list = LIST_HEAD_INIT(tsk.run_list), \
+ .time_slice = HZ, \
+ .tasks = LIST_HEAD_INIT(tsk.tasks), \
+ .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \
+ .ptraced = LIST_HEAD_INIT(tsk.ptraced), \
+ .ptrace_entry = LIST_HEAD_INIT(tsk.ptrace_entry), \
+ .real_parent = &tsk, \
+ .parent = &tsk, \
+ .children = LIST_HEAD_INIT(tsk.children), \
+ .sibling = LIST_HEAD_INIT(tsk.sibling), \
+ .group_leader = &tsk, \
+ .real_cred = &init_cred, \
+ .cred = &init_cred, \
+ .cred_guard_mutex = \
+ __MUTEX_INITIALIZER(tsk.cred_guard_mutex), \
+ .comm = "swapper", \
+ .thread = INIT_THREAD, \
+ .fs = &init_fs, \
+ .files = &init_files, \
+ .signal = &init_signals, \
+ .sighand = &init_sighand, \
+ .nsproxy = &init_nsproxy, \
+ .pending = { \
+ .list = LIST_HEAD_INIT(tsk.pending.list), \
+ .signal = {{0}}}, \
+ .blocked = {{0}}, \
+ .alloc_lock = __SPIN_LOCK_UNLOCKED(tsk.alloc_lock), \
+ .journal_info = NULL, \
+ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
+ .fs_excl = ATOMIC_INIT(0), \
+ .pi_lock = __SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
+ .timer_slack_ns = 50000, /* 50 usec default slack */ \
+ .pids = { \
+ [PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \
+ [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \
+ [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \
+ }, \
+ .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \
+ INIT_IDS \
+ INIT_PERF_EVENTS(tsk) \
+ INIT_TRACE_IRQFLAGS \
+ INIT_LOCKDEP \
+ INIT_FTRACE_GRAPH \
+ INIT_TRACE_RECURSION \
+ INIT_TASK_RCU_PREEMPT(tsk) \
+}
+#else /* CONFIG_SCHED_BFS */
#define INIT_TASK(tsk) \
{ \
.state = 0, \
@@ -185,7 +248,7 @@ extern struct cred init_cred;
INIT_TRACE_RECURSION \
INIT_TASK_RCU_PREEMPT(tsk) \
}
-
+#endif /* CONFIG_SCHED_BFS */
#define INIT_CPU_TIMERS(cpu_timers) \
{ \
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -64,6 +64,8 @@ static inline int task_ioprio_class(stru
static inline int task_nice_ioprio(struct task_struct *task)
{
+ if (iso_task(task))
+ return 0;
return (task_nice(task) + 20) / 5;
}
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -20,14 +20,24 @@ static inline int page_is_file_cache(str
}
static inline void
-add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
+__add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l, int tail)
{
- list_add(&page->lru, &zone->lru[l].list);
+ /* See if this should be added to the tail of this lru list */
+ if (tail)
+ list_add_tail(&page->lru, &zone->lru[l].list);
+ else
+ list_add(&page->lru, &zone->lru[l].list);
__inc_zone_state(zone, NR_LRU_BASE + l);
mem_cgroup_add_lru_list(page, l);
}
static inline void
+add_page_to_lru_list(struct zone *zone, struct page *page, enum lru_list l)
+{
+ __add_page_to_lru_list(zone, page, l, 0);
+}
+
+static inline void
del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
{
list_del(&page->lru);
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -15,6 +15,7 @@
#include <linux/seqlock.h>
#include <linux/nodemask.h>
#include <linux/pageblock-flags.h>
+#include <linux/timer.h>
#include <linux/bounds.h>
#include <asm/atomic.h>
#include <asm/page.h>
@@ -159,12 +160,14 @@ enum zone_watermarks {
WMARK_MIN,
WMARK_LOW,
WMARK_HIGH,
+ WMARK_LOTS,
NR_WMARK
};
#define min_wmark_pages(z) (z->watermark[WMARK_MIN])
#define low_wmark_pages(z) (z->watermark[WMARK_LOW])
#define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
+#define lots_wmark_pages(z) (z->watermark[WMARK_LOTS])
struct per_cpu_pages {
int count; /* number of pages in the list */
@@ -339,7 +342,7 @@ struct zone {
ZONE_PADDING(_pad1_)
/* Fields commonly accessed by the page reclaim scanner */
- spinlock_t lru_lock;
+ spinlock_t lru_lock;
struct zone_lru {
struct list_head list;
} lru[NR_LRU_LISTS];
@@ -652,6 +655,7 @@ typedef struct pglist_data {
wait_queue_head_t kswapd_wait;
struct task_struct *kswapd;
int kswapd_max_order;
+ struct timer_list watermark_timer;
} pg_data_t;
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
@@ -668,7 +672,7 @@ typedef struct pglist_data {
void get_zone_counts(unsigned long *active, unsigned long *inactive,
unsigned long *free);
void build_all_zonelists(void);
-void wakeup_kswapd(struct zone *zone, int order);
+void wakeup_kswapd(struct zone *zone, int order, struct task_struct *p);
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
int classzone_idx, int alloc_flags);
enum memmap_context {
--- a/include/linux/nfsd/stats.h
+++ b/include/linux/nfsd/stats.h
@@ -11,8 +11,8 @@
#include <linux/nfs4.h>
-/* thread usage wraps very million seconds (approx one fortnight) */
-#define NFSD_USAGE_WRAP (HZ*1000000)
+/* thread usage wraps every one hundred thousand seconds (approx one day) */
+#define NFSD_USAGE_WRAP (HZ*100000)
#ifdef __KERNEL__
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -36,8 +36,15 @@
#define SCHED_FIFO 1
#define SCHED_RR 2
#define SCHED_BATCH 3
-/* SCHED_ISO: reserved but not implemented yet */
+/* SCHED_ISO: Implemented on BFS only */
#define SCHED_IDLE 5
+#ifdef CONFIG_SCHED_BFS
+#define SCHED_ISO 4
+#define SCHED_IDLEPRIO SCHED_IDLE
+#define SCHED_MAX (SCHED_IDLEPRIO)
+#define SCHED_RANGE(policy) ((policy) <= SCHED_MAX)
+#endif
+
/* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
#define SCHED_RESET_ON_FORK 0x40000000
@@ -142,6 +149,7 @@ extern unsigned long nr_uninterruptible(
extern unsigned long nr_iowait(void);
extern unsigned long nr_iowait_cpu(void);
extern unsigned long this_cpu_load(void);
+extern int above_background_load(void);
extern void calc_global_load(void);
@@ -260,9 +268,6 @@ extern asmlinkage void schedule_tail(str
extern void init_idle(struct task_struct *idle, int cpu);
extern void init_idle_bootup_task(struct task_struct *idle);
-extern int runqueue_is_locked(int cpu);
-extern void task_rq_unlock_wait(struct task_struct *p);
-
extern cpumask_var_t nohz_cpu_mask;
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
extern int select_nohz_load_balancer(int cpu);
@@ -1236,17 +1241,31 @@ struct task_struct {
int lock_depth; /* BKL lock depth */
+#ifndef CONFIG_SCHED_BFS
#ifdef CONFIG_SMP
#ifdef __ARCH_WANT_UNLOCKED_CTXSW
int oncpu;
#endif
#endif
+#else /* CONFIG_SCHED_BFS */
+ int oncpu;
+#endif
int prio, static_prio, normal_prio;
unsigned int rt_priority;
+#ifdef CONFIG_SCHED_BFS
+ int time_slice;
+ u64 deadline;
+ struct list_head run_list;
+ u64 last_ran;
+ u64 sched_time; /* sched_clock time spent running */
+
+ unsigned long rt_timeout;
+#else /* CONFIG_SCHED_BFS */
const struct sched_class *sched_class;
struct sched_entity se;
struct sched_rt_entity rt;
+#endif
#ifdef CONFIG_PREEMPT_NOTIFIERS
/* list of struct preempt_notifier: */
@@ -1345,6 +1364,9 @@ struct task_struct {
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
cputime_t utime, stime, utimescaled, stimescaled;
+#ifdef CONFIG_SCHED_BFS
+ unsigned long utime_pc, stime_pc;
+#endif
cputime_t gtime;
cputime_t prev_utime, prev_stime;
unsigned long nvcsw, nivcsw; /* context switch counts */
@@ -1556,6 +1578,64 @@ struct task_struct {
cputime64_t iowait;
};
+#ifdef CONFIG_SCHED_BFS
+extern int grunqueue_is_locked(void);
+extern void grq_unlock_wait(void);
+#define tsk_seruntime(t) ((t)->sched_time)
+#define tsk_rttimeout(t) ((t)->rt_timeout)
+#define task_rq_unlock_wait(tsk) grq_unlock_wait()
+
+static inline void set_oom_timeslice(struct task_struct *p)
+{
+ p->time_slice = HZ;
+}
+
+static inline void tsk_cpus_current(struct task_struct *p)
+{
+}
+
+#define runqueue_is_locked(cpu) grunqueue_is_locked()
+
+static inline void print_scheduler_version(void)
+{
+ printk(KERN_INFO"BFS CPU scheduler v0.357 by Con Kolivas.\n");
+}
+
+static inline int iso_task(struct task_struct *p)
+{
+ return (p->policy == SCHED_ISO);
+}
+#else
+extern int runqueue_is_locked(int cpu);
+extern void task_rq_unlock_wait(struct task_struct *p);
+#define tsk_seruntime(t) ((t)->se.sum_exec_runtime)
+#define tsk_rttimeout(t) ((t)->rt.timeout)
+
+static inline void sched_exit(struct task_struct *p)
+{
+}
+
+static inline void set_oom_timeslice(struct task_struct *p)
+{
+ p->rt.time_slice = HZ;
+}
+
+static inline void tsk_cpus_current(struct task_struct *p)
+{
+ p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
+}
+
+static inline void print_scheduler_version(void)
+{
+ printk(KERN_INFO"CFS CPU scheduler.\n");
+}
+
+static inline int iso_task(struct task_struct *p)
+{
+ return 0;
+}
+#endif
+
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)
@@ -1574,9 +1654,19 @@ struct task_struct {
#define MAX_USER_RT_PRIO 100
#define MAX_RT_PRIO MAX_USER_RT_PRIO
+#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
+#ifdef CONFIG_SCHED_BFS
+#define PRIO_RANGE (40)
+#define MAX_PRIO (MAX_RT_PRIO + PRIO_RANGE)
+#define ISO_PRIO (MAX_RT_PRIO)
+#define NORMAL_PRIO (MAX_RT_PRIO + 1)
+#define IDLE_PRIO (MAX_RT_PRIO + 2)
+#define PRIO_LIMIT ((IDLE_PRIO) + 1)
+#else /* CONFIG_SCHED_BFS */
#define MAX_PRIO (MAX_RT_PRIO + 40)
-#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
+#define NORMAL_PRIO DEFAULT_PRIO
+#endif /* CONFIG_SCHED_BFS */
static inline int rt_prio(int prio)
{
@@ -1889,7 +1979,7 @@ task_sched_runtime(struct task_struct *t
extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
/* sched_exec is called by processes performing an exec */
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_BFS)
extern void sched_exec(void);
#else
#define sched_exec() {}
@@ -2058,6 +2148,9 @@ extern void wake_up_new_task(struct task
static inline void kick_process(struct task_struct *tsk) { }
#endif
extern void sched_fork(struct task_struct *p, int clone_flags);
+#ifdef CONFIG_SCHED_BFS
+extern void sched_exit(struct task_struct *p);
+#endif
extern void sched_dead(struct task_struct *p);
extern void proc_caches_init(void);
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -198,6 +198,7 @@ extern unsigned int nr_free_pagecache_pa
/* linux/mm/swap.c */
+extern void ____lru_cache_add(struct page *, enum lru_list lru, int tail);
extern void __lru_cache_add(struct page *, enum lru_list lru);
extern void lru_cache_add_lru(struct page *, enum lru_list lru);
extern void activate_page(struct page *);
@@ -218,9 +219,9 @@ static inline void lru_cache_add_anon(st
__lru_cache_add(page, LRU_INACTIVE_ANON);
}
-static inline void lru_cache_add_file(struct page *page)
+static inline void lru_cache_add_file(struct page *page, int tail)
{
- __lru_cache_add(page, LRU_INACTIVE_FILE);
+ ____lru_cache_add(page, LRU_INACTIVE_FILE, tail);
}
/* linux/mm/vmscan.c */
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -39,8 +39,8 @@ struct inet_hashinfo;
* If time > 4sec, it is "slow" path, no recycling is required,
* so that we select tick to get range about 4 seconds.
*/
-#if HZ <= 16 || HZ > 4096
-# error Unsupported: HZ <= 16 or HZ > 4096
+#if HZ <= 16 || HZ > 16384
+# error Unsupported: HZ <= 16 or HZ > 16384
#elif HZ <= 32
# define INET_TWDR_RECYCLE_TICK (5 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 64
@@ -55,8 +55,12 @@ struct inet_hashinfo;
# define INET_TWDR_RECYCLE_TICK (10 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#elif HZ <= 2048
# define INET_TWDR_RECYCLE_TICK (11 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
-#else
+#elif HZ <= 4096
# define INET_TWDR_RECYCLE_TICK (12 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
+#elif HZ <= 8192
+# define INET_TWDR_RECYCLE_TICK (13 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
+#else
+# define INET_TWDR_RECYCLE_TICK (14 + 2 - INET_TWDR_RECYCLE_SLOTS_LOG)
#endif
/* TIME_WAIT reaping mechanism. */
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -23,6 +23,19 @@ config CONSTRUCTORS
menu "General setup"
+config SCHED_BFS
+ bool "BFS cpu scheduler"
+ ---help---
+ The Brain Fuck CPU Scheduler for excellent interactivity and
+ responsiveness on the desktop and solid scalability on normal
+ hardware. Not recommended for 4096 CPUs.
+
+ Currently incompatible with the Group CPU scheduler, and RCU TORTURE
+ TEST so these options are disabled.
+
+ Say Y here.
+ default y
+
config EXPERIMENTAL
bool "Prompt for development and/or incomplete code/drivers"
---help---
@@ -428,7 +441,7 @@ config HAVE_UNSTABLE_SCHED_CLOCK
config GROUP_SCHED
bool "Group CPU scheduler"
- depends on EXPERIMENTAL
+ depends on EXPERIMENTAL && !SCHED_BFS
default n
help
This feature lets CPU scheduler recognize task groups and control CPU
@@ -544,7 +557,7 @@ config PROC_PID_CPUSET
config CGROUP_CPUACCT
bool "Simple CPU accounting cgroup subsystem"
- depends on CGROUPS
+ depends on CGROUPS && !SCHED_BFS
help
Provides a simple Resource Controller for monitoring the
total CPU consumed by the tasks in a cgroup.
--- a/init/calibrate.c
+++ b/init/calibrate.c
@@ -176,7 +176,7 @@ void __cpuinit calibrate_delay(void)
if (!printed)
pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
loops_per_jiffy/(500000/HZ),
- (loops_per_jiffy/(5000/HZ)) % 100, loops_per_jiffy);
+ (loops_per_jiffy * 10 /(50000/HZ)) % 100, loops_per_jiffy);
printed = true;
}
--- a/init/main.c
+++ b/init/main.c
@@ -806,6 +806,8 @@ static noinline int init_post(void)
system_state = SYSTEM_RUNNING;
numa_default_policy();
+ print_scheduler_version();
+
if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
printk(KERN_WARNING "Warning: unable to open an initial console.\n");
--- a/kernel/Kconfig.hz
+++ b/kernel/Kconfig.hz
@@ -4,7 +4,7 @@
choice
prompt "Timer frequency"
- default HZ_250
+ default HZ_1000
help
Allows the configuration of the timer frequency. It is customary
to have the timer interrupt run at 1000 Hz but 100 Hz may be more
@@ -23,13 +23,14 @@ choice
with lots of processors that may show reduced performance if
too many timer interrupts are occurring.
- config HZ_250
+ config HZ_250_NODEFAULT
bool "250 HZ"
help
- 250 Hz is a good compromise choice allowing server performance
- while also showing good interactive responsiveness even
- on SMP and NUMA systems. If you are going to be using NTSC video
- or multimedia, selected 300Hz instead.
+ 250 HZ is a lousy compromise choice allowing server interactivity
+ while also showing desktop throughput and no extra power saving on
+ laptops. No good for anything.
+
+ Recommend 100 or 1000 instead.
config HZ_300
bool "300 HZ"
@@ -43,16 +44,82 @@ choice
bool "1000 HZ"
help
1000 Hz is the preferred choice for desktop systems and other
- systems requiring fast interactive responses to events.
+ systems requiring fast interactive responses to events. Laptops
+ can also benefit from this choice without sacrificing battery life
+ if dynticks is also enabled.
+
+ config HZ_1500
+ bool "1500 HZ"
+ help
+ 1500 Hz is an insane value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_2000
+ bool "2000 HZ"
+ help
+ 2000 Hz is an insane value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_3000
+ bool "3000 HZ"
+ help
+ 3000 Hz is an insane value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_4000
+ bool "4000 HZ"
+ help
+ 4000 Hz is an insane value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_5000
+ bool "5000 HZ"
+ help
+ 5000 Hz is an obscene value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_7500
+ bool "7500 HZ"
+ help
+ 7500 Hz is an obscene value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
+ config HZ_10000
+ bool "10000 HZ"
+ help
+ 10000 Hz is an obscene value to use to run broken software that is Hz
+ limited.
+
+ Being over 1000, driver breakage is likely.
+
endchoice
config HZ
int
default 100 if HZ_100
- default 250 if HZ_250
+ default 250 if HZ_250_NODEFAULT
default 300 if HZ_300
default 1000 if HZ_1000
+ default 1500 if HZ_1500
+ default 2000 if HZ_2000
+ default 3000 if HZ_3000
+ default 4000 if HZ_4000
+ default 5000 if HZ_5000
+ default 7500 if HZ_7500
+ default 10000 if HZ_10000
config SCHED_HRTICK
def_bool HIGH_RES_TIMERS && (!SMP || USE_GENERIC_SMP_HELPERS)
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -1,7 +1,7 @@
choice
prompt "Preemption Model"
- default PREEMPT_NONE
+ default PREEMPT
config PREEMPT_NONE
bool "No Forced Preemption (Server)"
@@ -17,7 +17,7 @@ config PREEMPT_NONE
latencies.
config PREEMPT_VOLUNTARY
- bool "Voluntary Kernel Preemption (Desktop)"
+ bool "Voluntary Kernel Preemption (Nothing)"
help
This option reduces the latency of the kernel by adding more
"explicit preemption points" to the kernel code. These new
@@ -31,7 +31,8 @@ config PREEMPT_VOLUNTARY
applications to run more 'smoothly' even when the system is
under load.
- Select this if you are building a kernel for a desktop system.
+ Select this for no system in particular (choose Preemptible
+ instead on a desktop if you know what's good for you).
config PREEMPT
bool "Preemptible Kernel (Low-Latency Desktop)"
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -128,7 +128,7 @@ int __delayacct_add_tsk(struct taskstats
*/
t1 = tsk->sched_info.pcount;
t2 = tsk->sched_info.run_delay;
- t3 = tsk->se.sum_exec_runtime;
+ t3 = tsk_seruntime(tsk);
d->cpu_count += t1;
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -120,7 +120,7 @@ static void __exit_signal(struct task_st
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
task_io_accounting_add(&sig->ioac, &tsk->ioac);
- sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
+ sig->sum_sched_runtime += tsk_seruntime(tsk);
sig = NULL; /* Marker for below. */
}
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -250,7 +250,7 @@ void thread_group_cputime(struct task_st
do {
times->utime = cputime_add(times->utime, t->utime);
times->stime = cputime_add(times->stime, t->stime);
- times->sum_exec_runtime += t->se.sum_exec_runtime;
+ times->sum_exec_runtime += tsk_seruntime(t);
t = next_thread(t);
} while (t != tsk);
@@ -517,7 +517,7 @@ static void cleanup_timers(struct list_h
void posix_cpu_timers_exit(struct task_struct *tsk)
{
cleanup_timers(tsk->cpu_timers,
- tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
+ tsk->utime, tsk->stime, tsk_seruntime(tsk));
}
void posix_cpu_timers_exit_group(struct task_struct *tsk)
@@ -527,7 +527,7 @@ void posix_cpu_timers_exit_group(struct
cleanup_timers(tsk->signal->cpu_timers,
cputime_add(tsk->utime, sig->utime),
cputime_add(tsk->stime, sig->stime),
- tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
+ tsk_seruntime(tsk) + sig->sum_sched_runtime);
}
static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
@@ -1020,7 +1020,7 @@ static void check_thread_timers(struct t
struct cpu_timer_list *t = list_first_entry(timers,
struct cpu_timer_list,
entry);
- if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {
+ if (!--maxfire || tsk_seruntime(tsk) < t->expires.sched) {
tsk->cputime_expires.sched_exp = t->expires.sched;
break;
}
@@ -1036,7 +1036,7 @@ static void check_thread_timers(struct t
unsigned long *soft = &sig->rlim[RLIMIT_RTTIME].rlim_cur;
if (hard != RLIM_INFINITY &&
- tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
+ tsk_rttimeout(tsk) > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
/*
* At the hard limit, we just die.
* No need to calculate anything else now.
@@ -1044,7 +1044,7 @@ static void check_thread_timers(struct t
__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
return;
}
- if (tsk->rt.timeout > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) {
+ if (tsk_rttimeout(tsk) > DIV_ROUND_UP(*soft, USEC_PER_SEC/HZ)) {
/*
* At the soft limit, send a SIGXCPU every second.
*/
@@ -1367,7 +1367,7 @@ static inline int fastpath_timer_check(s
struct task_cputime task_sample = {
.utime = tsk->utime,
.stime = tsk->stime,
- .sum_exec_runtime = tsk->se.sum_exec_runtime
+ .sum_exec_runtime = tsk_seruntime(tsk)
};
if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1,3 +1,6 @@
+#ifdef CONFIG_SCHED_BFS
+#include "sched_bfs.c"
+#else
/*
* kernel/sched.c
*
@@ -11135,3 +11138,4 @@ void synchronize_sched_expedited(void)
EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
#endif /* #else #ifndef CONFIG_SMP */
+#endif /* CONFIG_SCHED_BFS */
--- /dev/null
+++ b/kernel/sched_bfs.c
@@ -0,0 +1,6890 @@
+/*
+ * kernel/sched_bfs.c, was sched.c
+ *
+ * Kernel scheduler and related syscalls
+ *
+ * Copyright (C) 1991-2002 Linus Torvalds
+ *
+ * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
+ * make semaphores SMP safe
+ * 1998-11-19 Implemented schedule_timeout() and related stuff
+ * by Andrea Arcangeli
+ * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
+ * hybrid priority-list and round-robin design with
+ * an array-switch method of distributing timeslices
+ * and per-CPU runqueues. Cleanups and useful suggestions
+ * by Davide Libenzi, preemptible kernel bits by Robert Love.
+ * 2003-09-03 Interactivity tuning by Con Kolivas.
+ * 2004-04-02 Scheduler domains code by Nick Piggin
+ * 2007-04-15 Work begun on replacing all interactivity tuning with a
+ * fair scheduling design by Con Kolivas.
+ * 2007-05-05 Load balancing (smp-nice) and other improvements
+ * by Peter Williams
+ * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
+ * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
+ * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
+ * Thomas Gleixner, Mike Kravetz
+ * now Brainfuck deadline scheduling policy by Con Kolivas deletes
+ * a whole lot of those previous things.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/nmi.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <linux/highmem.h>
+#include <linux/smp_lock.h>
+#include <asm/mmu_context.h>
+#include <linux/interrupt.h>
+#include <linux/capability.h>
+#include <linux/completion.h>
+#include <linux/kernel_stat.h>
+#include <linux/debug_locks.h>
+#include <linux/perf_event.h>
+#include <linux/security.h>
+#include <linux/notifier.h>
+#include <linux/profile.h>
+#include <linux/freezer.h>
+#include <linux/vmalloc.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <linux/timer.h>
+#include <linux/rcupdate.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/kthread.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/syscalls.h>
+#include <linux/times.h>
+#include <linux/tsacct_kern.h>
+#include <linux/kprobes.h>
+#include <linux/delayacct.h>
+#include <linux/log2.h>
+#include <linux/bootmem.h>
+#include <linux/ftrace.h>
+
+#include <asm/tlb.h>
+#include <asm/unistd.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/sched.h>
+
+#define rt_prio(prio) unlikely((prio) < MAX_RT_PRIO)
+#define rt_task(p) rt_prio((p)->prio)
+#define rt_queue(rq) rt_prio((rq)->rq_prio)
+#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH))
+#define is_rt_policy(policy) ((policy) == SCHED_FIFO || \
+ (policy) == SCHED_RR)
+#define has_rt_policy(p) unlikely(is_rt_policy((p)->policy))
+#define idleprio_task(p) unlikely((p)->policy == SCHED_IDLEPRIO)
+#define iso_task(p) unlikely((p)->policy == SCHED_ISO)
+#define iso_queue(rq) unlikely((rq)->rq_policy == SCHED_ISO)
+#define ISO_PERIOD ((5 * HZ * num_online_cpus()) + 1)
+
+/*
+ * Convert user-nice values [ -20 ... 0 ... 19 ]
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
+ * and back.
+ */
+#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
+#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
+#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
+
+/*
+ * 'User priority' is the nice value converted to something we
+ * can work with better when scaling various scheduler parameters,
+ * it's a [ 0 ... 39 ] range.
+ */
+#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
+#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
+#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
+#define SCHED_PRIO(p) ((p)+MAX_RT_PRIO)
+
+/*
+ * Some helpers for converting to/from various scales. Use shifts to get
+ * approximate multiples of ten for less overhead.
+ */
+#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
+#define JIFFY_NS (1000000000 / HZ)
+#define HALF_JIFFY_NS (1000000000 / HZ / 2)
+#define HALF_JIFFY_US (1000000 / HZ / 2)
+#define MS_TO_NS(TIME) ((TIME) << 20)
+#define MS_TO_US(TIME) ((TIME) << 10)
+#define US_TO_NS(TIME) ((TIME) >> 10)
+#define NS_TO_MS(TIME) ((TIME) >> 20)
+#define NS_TO_US(TIME) ((TIME) >> 10)
+
+#define RESCHED_US (100) /* Reschedule if less than this many us left */
+
+/*
+ * This is the time all tasks within the same priority round robin.
+ * Value is in ms and set to a minimum of 6ms. Scales with number of cpus.
+ * Tunable via /proc interface.
+ */
+int rr_interval __read_mostly = 6;
+
+/*
+ * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks
+ * are allowed to run five seconds as real time tasks. This is the total over
+ * all online cpus.
+ */
+int sched_iso_cpu __read_mostly = 70;
+
+/*
+ * The relative length of deadline for each priority(nice) level.
+ */
+static int prio_ratios[PRIO_RANGE] __read_mostly;
+
+/*
+ * The quota handed out to tasks of all priority levels when refilling their
+ * time_slice.
+ */
+static inline unsigned long timeslice(void)
+{
+ return MS_TO_US(rr_interval);
+}
+
+/*
+ * The global runqueue data that all CPUs work off. Data is protected either
+ * by the global grq lock, or the discrete lock that precedes the data in this
+ * struct.
+ */
+struct global_rq {
+ spinlock_t lock;
+ unsigned long nr_running;
+ unsigned long nr_uninterruptible;
+ unsigned long long nr_switches;
+ struct list_head queue[PRIO_LIMIT];
+ DECLARE_BITMAP(prio_bitmap, PRIO_LIMIT + 1);
+#ifdef CONFIG_SMP
+ unsigned long qnr; /* queued not running */
+ cpumask_t cpu_idle_map;
+ int idle_cpus;
+#endif
+ u64 niffies; /* Nanosecond jiffies */
+ unsigned long last_jiffy; /* Last jiffy we updated niffies */
+
+ spinlock_t iso_lock;
+ int iso_ticks;
+ int iso_refractory;
+};
+
+/* There can be only one */
+static struct global_rq grq;
+
+/*
+ * This is the main, per-CPU runqueue data structure.
+ * This data should only be modified by the local cpu.
+ */
+struct rq {
+#ifdef CONFIG_SMP
+#ifdef CONFIG_NO_HZ
+ unsigned char in_nohz_recently;
+#endif
+ struct task_struct *last_task;
+#endif
+
+ struct task_struct *curr, *idle;
+ struct mm_struct *prev_mm;
+
+ /* Stored data about rq->curr to work outside grq lock */
+ u64 rq_deadline;
+ unsigned int rq_policy;
+ int rq_time_slice;
+ u64 rq_last_ran;
+ int rq_prio;
+ int rq_running; /* There is a task running */
+
+ /* Accurate timekeeping data */
+ u64 timekeep_clock;
+ unsigned long user_pc, nice_pc, irq_pc, softirq_pc, system_pc,
+ iowait_pc, idle_pc;
+ atomic_t nr_iowait;
+
+#ifdef CONFIG_SMP
+ int cpu; /* cpu of this runqueue */
+ int online;
+
+ struct root_domain *rd;
+ struct sched_domain *sd;
+ unsigned long *cpu_locality; /* CPU relative cache distance */
+#ifdef CONFIG_SCHED_SMT
+ int (*siblings_idle)(unsigned long cpu);
+ /* See if all smt siblings are idle */
+ cpumask_t smt_siblings;
+#endif
+#ifdef CONFIG_SCHED_MC
+ int (*cache_idle)(unsigned long cpu);
+ /* See if all cache siblings are idle */
+ cpumask_t cache_siblings;
+#endif
+ u64 last_niffy; /* Last time this RQ updated grq.niffies */
+#endif
+ u64 clock, old_clock, last_tick;
+ int dither;
+
+#ifdef CONFIG_SCHEDSTATS
+
+ /* latency stats */
+ struct sched_info rq_sched_info;
+ unsigned long long rq_cpu_time;
+ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
+
+ /* sys_sched_yield() stats */
+ unsigned int yld_count;
+
+ /* schedule() stats */
+ unsigned int sched_switch;
+ unsigned int sched_count;
+ unsigned int sched_goidle;
+
+ /* try_to_wake_up() stats */
+ unsigned int ttwu_count;
+ unsigned int ttwu_local;
+
+ /* BKL stats */
+ unsigned int bkl_count;
+#endif
+};
+
+static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp;
+static DEFINE_MUTEX(sched_hotcpu_mutex);
+
+#ifdef CONFIG_SMP
+
+/*
+ * We add the notion of a root-domain which will be used to define per-domain
+ * variables. Each exclusive cpuset essentially defines an island domain by
+ * fully partitioning the member cpus from any other cpuset. Whenever a new
+ * exclusive cpuset is created, we also create and attach a new root-domain
+ * object.
+ *
+ */
+struct root_domain {
+ atomic_t refcount;
+ cpumask_var_t span;
+ cpumask_var_t online;
+
+ /*
+ * The "RT overload" flag: it gets set if a CPU has more than
+ * one runnable RT task.
+ */
+ cpumask_var_t rto_mask;
+ atomic_t rto_count;
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+ /*
+ * Preferred wake up cpu nominated by sched_mc balance that will be
+ * used when most cpus are idle in the system indicating overall very
+ * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
+ */
+ unsigned int sched_mc_preferred_wakeup_cpu;
+#endif
+};
+
+/*
+ * By default the system creates a single root-domain with all cpus as
+ * members (mimicking the global state we have today).
+ */
+static struct root_domain def_root_domain;
+#endif
+
+/*
+ * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
+ * See detach_destroy_domains: synchronize_sched for details.
+ *
+ * The domain tree of any CPU may only be accessed from within
+ * preempt-disabled sections.
+ */
+#define for_each_domain(cpu, __sd) \
+ for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
+
+static inline void update_rq_clock(struct rq *rq);
+
+/*
+ * Sanity check should sched_clock return bogus values. We make sure it does
+ * not appear to go backwards, and use jiffies to determine the maximum it
+ * could possibly have increased. At least 1us will have always passed so we
+ * use that when we don't trust the difference.
+ */
+static inline void niffy_diff(s64 *niff_diff, int jiff_diff)
+{
+ unsigned long max_diff;
+
+ /* Round up to the nearest tick for maximum */
+ max_diff = JIFFIES_TO_NS(jiff_diff + 1);
+
+ if (unlikely(*niff_diff < 1 || *niff_diff > max_diff))
+ *niff_diff = US_TO_NS(1);
+}
+
+#ifdef CONFIG_SMP
+#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
+#define this_rq() (&__get_cpu_var(runqueues))
+#define task_rq(p) cpu_rq(task_cpu(p))
+#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
+static inline int cpu_of(struct rq *rq)
+{
+ return rq->cpu;
+}
+
+/*
+ * Niffies are a globally increasing nanosecond counter. Whenever a runqueue
+ * clock is updated with the grq.lock held, it is an opportunity to update the
+ * niffies value. Any CPU can update it by adding how much its clock has
+ * increased since it last updated niffies, minus any added niffies by other
+ * CPUs.
+ */
+static inline void update_clocks(struct rq *rq)
+{
+ s64 ndiff;
+ long jdiff;
+
+ update_rq_clock(rq);
+ ndiff = rq->clock - rq->old_clock;
+ /* old_clock is only updated when we are updating niffies */
+ rq->old_clock = rq->clock;
+ ndiff -= grq.niffies - rq->last_niffy;
+ jdiff = jiffies - grq.last_jiffy;
+ niffy_diff(&ndiff, jdiff);
+ grq.last_jiffy += jdiff;
+ grq.niffies += ndiff;
+ rq->last_niffy = grq.niffies;
+}
+#else /* CONFIG_SMP */
+static struct rq *uprq;
+#define cpu_rq(cpu) (uprq)
+#define this_rq() (uprq)
+#define task_rq(p) (uprq)
+#define cpu_curr(cpu) ((uprq)->curr)
+static inline int cpu_of(struct rq *rq)
+{
+ return 0;
+}
+
+static inline void update_clocks(struct rq *rq)
+{
+ s64 ndiff;
+ long jdiff;
+
+ update_rq_clock(rq);
+ ndiff = rq->clock - rq->old_clock;
+ rq->old_clock = rq->clock;
+ jdiff = jiffies - grq.last_jiffy;
+ niffy_diff(&ndiff, jdiff);
+ grq.last_jiffy += jdiff;
+ grq.niffies += ndiff;
+}
+#endif
+#define raw_rq() (&__raw_get_cpu_var(runqueues))
+
+#include "sched_stats.h"
+
+#ifndef prepare_arch_switch
+# define prepare_arch_switch(next) do { } while (0)
+#endif
+#ifndef finish_arch_switch
+# define finish_arch_switch(prev) do { } while (0)
+#endif
+
+/*
+ * All common locking functions performed on grq.lock. rq->clock is local to
+ * the CPU accessing it so it can be modified just with interrupts disabled
+ * when we're not updating niffies.
+ * Looking up task_rq must be done under grq.lock to be safe.
+ */
+static inline void update_rq_clock(struct rq *rq)
+{
+ rq->clock = sched_clock_cpu(cpu_of(rq));
+}
+
+static inline int task_running(struct task_struct *p)
+{
+ return p->oncpu;
+}
+
+static inline void grq_lock(void)
+ __acquires(grq.lock)
+{
+ spin_lock(&grq.lock);
+}
+
+static inline void grq_unlock(void)
+ __releases(grq.lock)
+{
+ spin_unlock(&grq.lock);
+}
+
+static inline void grq_lock_irq(void)
+ __acquires(grq.lock)
+{
+ spin_lock_irq(&grq.lock);
+}
+
+static inline void time_lock_grq(struct rq *rq)
+ __acquires(grq.lock)
+{
+ grq_lock();
+ update_clocks(rq);
+}
+
+static inline void grq_unlock_irq(void)
+ __releases(grq.lock)
+{
+ spin_unlock_irq(&grq.lock);
+}
+
+static inline void grq_lock_irqsave(unsigned long *flags)
+ __acquires(grq.lock)
+{
+ spin_lock_irqsave(&grq.lock, *flags);
+}
+
+static inline void grq_unlock_irqrestore(unsigned long *flags)
+ __releases(grq.lock)
+{
+ spin_unlock_irqrestore(&grq.lock, *flags);
+}
+
+static inline struct rq
+*task_grq_lock(struct task_struct *p, unsigned long *flags)
+ __acquires(grq.lock)
+{
+ grq_lock_irqsave(flags);
+ return task_rq(p);
+}
+
+static inline struct rq
+*time_task_grq_lock(struct task_struct *p, unsigned long *flags)
+ __acquires(grq.lock)
+{
+ struct rq *rq = task_grq_lock(p, flags);
+ update_clocks(rq);
+ return rq;
+}
+
+static inline struct rq *task_grq_lock_irq(struct task_struct *p)
+ __acquires(grq.lock)
+{
+ grq_lock_irq();
+ return task_rq(p);
+}
+
+static inline void time_task_grq_lock_irq(struct task_struct *p)
+ __acquires(grq.lock)
+{
+ struct rq *rq = task_grq_lock_irq(p);
+ update_clocks(rq);
+}
+
+static inline void task_grq_unlock_irq(void)
+ __releases(grq.lock)
+{
+ grq_unlock_irq();
+}
+
+static inline void task_grq_unlock(unsigned long *flags)
+ __releases(grq.lock)
+{
+ grq_unlock_irqrestore(flags);
+}
+
+/**
+ * grunqueue_is_locked
+ *
+ * Returns true if the global runqueue is locked.
+ * This interface allows printk to be called with the runqueue lock
+ * held and know whether or not it is OK to wake up the klogd.
+ */
+inline int grunqueue_is_locked(void)
+{
+ return spin_is_locked(&grq.lock);
+}
+
+inline void grq_unlock_wait(void)
+ __releases(grq.lock)
+{
+ smp_mb(); /* spin-unlock-wait is not a full memory barrier */
+ spin_unlock_wait(&grq.lock);
+}
+
+static inline void time_grq_lock(struct rq *rq, unsigned long *flags)
+ __acquires(grq.lock)
+{
+ local_irq_save(*flags);
+ time_lock_grq(rq);
+}
+
+static inline struct rq *__task_grq_lock(struct task_struct *p)
+ __acquires(grq.lock)
+{
+ grq_lock();
+ return task_rq(p);
+}
+
+static inline void __task_grq_unlock(void)
+ __releases(grq.lock)
+{
+ grq_unlock();
+}
+
+/*
+ * Look for any tasks *anywhere* that are running nice 0 or better. We do
+ * this lockless for overhead reasons since the occasional wrong result
+ * is harmless.
+ */
+int above_background_load(void)
+{
+ struct task_struct *cpu_curr;
+ unsigned long cpu;
+
+ for_each_online_cpu(cpu) {
+ cpu_curr = cpu_rq(cpu)->curr;
+ if (unlikely(!cpu_curr))
+ continue;
+ if (PRIO_TO_NICE(cpu_curr->static_prio) < 1)
+ return 1;
+ }
+ return 0;
+}
+
+#ifndef __ARCH_WANT_UNLOCKED_CTXSW
+static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
+{
+}
+
+static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
+{
+#ifdef CONFIG_DEBUG_SPINLOCK
+ /* this is a valid case when another task releases the spinlock */
+ grq.lock.owner = current;
+#endif
+ /*
+ * If we are tracking spinlock dependencies then we have to
+ * fix up the runqueue lock - which gets 'carried over' from
+ * prev into current:
+ */
+ spin_acquire(&grq.lock.dep_map, 0, 0, _THIS_IP_);
+
+ grq_unlock_irq();
+}
+
+#else /* __ARCH_WANT_UNLOCKED_CTXSW */
+
+static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
+{
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+ grq_unlock_irq();
+#else
+ grq_unlock();
+#endif
+}
+
+static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
+{
+ smp_wmb();
+#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+ local_irq_enable();
+#endif
+}
+#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
+
+static inline int deadline_before(u64 deadline, u64 time)
+{
+ return (deadline < time);
+}
+
+static inline int deadline_after(u64 deadline, u64 time)
+{
+ return (deadline > time);
+}
+
+/*
+ * A task that is queued but not running will be on the grq run list.
+ * A task that is not running or queued will not be on the grq run list.
+ * A task that is currently running will have ->oncpu set but not on the
+ * grq run list.
+ */
+static inline int task_queued(struct task_struct *p)
+{
+ return (!list_empty(&p->run_list));
+}
+
+/*
+ * Removing from the global runqueue. Enter with grq locked.
+ */
+static void dequeue_task(struct task_struct *p)
+{
+ list_del_init(&p->run_list);
+ if (list_empty(grq.queue + p->prio))
+ __clear_bit(p->prio, grq.prio_bitmap);
+}
+
+/*
+ * To determine if it's safe for a task of SCHED_IDLEPRIO to actually run as
+ * an idle task, we ensure none of the following conditions are met.
+ */
+static int idleprio_suitable(struct task_struct *p)
+{
+ return (!freezing(p) && !signal_pending(p) &&
+ !(task_contributes_to_load(p)) && !(p->flags & (PF_EXITING)));
+}
+
+/*
+ * To determine if a task of SCHED_ISO can run in pseudo-realtime, we check
+ * that the iso_refractory flag is not set.
+ */
+static int isoprio_suitable(void)
+{
+ return !grq.iso_refractory;
+}
+
+/*
+ * Adding to the global runqueue. Enter with grq locked.
+ */
+static void enqueue_task(struct task_struct *p)
+{
+ if (!rt_task(p)) {
+ /* Check it hasn't gotten rt from PI */
+ if ((idleprio_task(p) && idleprio_suitable(p)) ||
+ (iso_task(p) && isoprio_suitable()))
+ p->prio = p->normal_prio;
+ else
+ p->prio = NORMAL_PRIO;
+ }
+ __set_bit(p->prio, grq.prio_bitmap);
+ list_add_tail(&p->run_list, grq.queue + p->prio);
+ sched_info_queued(p);
+}
+
+/* Only idle task does this as a real time task*/
+static inline void enqueue_task_head(struct task_struct *p)
+{
+ __set_bit(p->prio, grq.prio_bitmap);
+ list_add(&p->run_list, grq.queue + p->prio);
+ sched_info_queued(p);
+}
+
+static inline void requeue_task(struct task_struct *p)
+{
+ sched_info_queued(p);
+}
+
+/*
+ * Returns the relative length of deadline all compared to the shortest
+ * deadline which is that of nice -20.
+ */
+static inline int task_prio_ratio(struct task_struct *p)
+{
+ return prio_ratios[TASK_USER_PRIO(p)];
+}
+
+/*
+ * task_timeslice - all tasks of all priorities get the exact same timeslice
+ * length. CPU distribution is handled by giving different deadlines to
+ * tasks of different priorities. Use 128 as the base value for fast shifts.
+ */
+static inline int task_timeslice(struct task_struct *p)
+{
+ return (rr_interval * task_prio_ratio(p) / 128);
+}
+
+#ifdef CONFIG_SMP
+/*
+ * qnr is the "queued but not running" count which is the total number of
+ * tasks on the global runqueue list waiting for cpu time but not actually
+ * currently running on a cpu.
+ */
+static inline void inc_qnr(void)
+{
+ grq.qnr++;
+}
+
+static inline void dec_qnr(void)
+{
+ grq.qnr--;
+}
+
+static inline int queued_notrunning(void)
+{
+ return grq.qnr;
+}
+
+/*
+ * The cpu_idle_map stores a bitmap of all the CPUs currently idle to
+ * allow easy lookup of whether any suitable idle CPUs are available.
+ * It's cheaper to maintain a binary yes/no if there are any idle CPUs on the
+ * idle_cpus variable than to do a full bitmask check when we are busy.
+ */
+static inline void set_cpuidle_map(unsigned long cpu)
+{
+ cpu_set(cpu, grq.cpu_idle_map);
+ grq.idle_cpus = 1;
+}
+
+static inline void clear_cpuidle_map(unsigned long cpu)
+{
+ cpu_clear(cpu, grq.cpu_idle_map);
+ if (cpus_empty(grq.cpu_idle_map))
+ grq.idle_cpus = 0;
+}
+
+static int suitable_idle_cpus(struct task_struct *p)
+{
+ if (!grq.idle_cpus)
+ return 0;
+ return (cpus_intersects(p->cpus_allowed, grq.cpu_idle_map));
+}
+
+static void resched_task(struct task_struct *p);
+
+/*
+ * last_task stores the last non-idle task scheduled on the local rq for
+ * cache warmth testing.
+ */
+static inline void set_last_task(struct rq *rq, struct task_struct *p)
+{
+ rq->last_task = p;
+}
+
+#define CPUIDLE_CACHE_BUSY (1)
+#define CPUIDLE_DIFF_CPU (2)
+#define CPUIDLE_THREAD_BUSY (4)
+#define CPUIDLE_DIFF_NODE (8)
+
+/*
+ * The best idle CPU is chosen according to the CPUIDLE ranking above where the
+ * lowest value would give the most suitable CPU to schedule p onto next. We
+ * iterate from the last CPU upwards instead of using for_each_cpu_mask so as
+ * to be able to break out immediately if the last CPU is idle. The order works
+ * out to be the following:
+ *
+ * Same core, idle or busy cache, idle threads
+ * Other core, same cache, idle or busy cache, idle threads.
+ * Same node, other CPU, idle cache, idle threads.
+ * Same node, other CPU, busy cache, idle threads.
+ * Same core, busy threads.
+ * Other core, same cache, busy threads.
+ * Same node, other CPU, busy threads.
+ * Other node, other CPU, idle cache, idle threads.
+ * Other node, other CPU, busy cache, idle threads.
+ * Other node, other CPU, busy threads.
+ *
+ * If p was the last task running on this rq, then regardless of where
+ * it has been running since then, it is cache warm on this rq.
+ */
+static void resched_best_idle(struct task_struct *p)
+{
+ unsigned long cpu_tmp, best_cpu, best_ranking;
+ cpumask_t tmpmask;
+ struct rq *rq;
+ int iterate;
+
+ cpus_and(tmpmask, p->cpus_allowed, grq.cpu_idle_map);
+ iterate = cpus_weight(tmpmask);
+ best_cpu = task_cpu(p);
+ /*
+ * Start below the last CPU and work up with next_cpu as the last
+ * CPU might not be idle or affinity might not allow it.
+ */
+ cpu_tmp = best_cpu - 1;
+ rq = cpu_rq(best_cpu);
+ best_ranking = ~0UL;
+
+ do {
+ unsigned long ranking;
+ struct rq *tmp_rq;
+
+ ranking = 0;
+ cpu_tmp = next_cpu(cpu_tmp, tmpmask);
+ if (cpu_tmp >= nr_cpu_ids) {
+ cpu_tmp = -1;
+ cpu_tmp = next_cpu(cpu_tmp, tmpmask);
+ }
+ tmp_rq = cpu_rq(cpu_tmp);
+
+ if (rq->cpu_locality[cpu_tmp]) {
+ /* Check rq->last_task hasn't been dereferenced */
+ if (rq->last_task && p != rq->last_task) {
+#ifdef CONFIG_NUMA
+ if (rq->cpu_locality[cpu_tmp] > 1)
+ ranking |= CPUIDLE_DIFF_NODE;
+#endif
+ ranking |= CPUIDLE_DIFF_CPU;
+ }
+ }
+#ifdef CONFIG_SCHED_MC
+ if (!(tmp_rq->cache_idle(cpu_tmp)))
+ ranking |= CPUIDLE_CACHE_BUSY;
+#endif
+#ifdef CONFIG_SCHED_SMT
+ if (!(tmp_rq->siblings_idle(cpu_tmp)))
+ ranking |= CPUIDLE_THREAD_BUSY;
+#endif
+ if (ranking < best_ranking) {
+ best_cpu = cpu_tmp;
+ if (ranking <= 1)
+ break;
+ best_ranking = ranking;
+ }
+ } while (--iterate > 0);
+
+ resched_task(cpu_rq(best_cpu)->curr);
+}
+
+static inline void resched_suitable_idle(struct task_struct *p)
+{
+ if (suitable_idle_cpus(p))
+ resched_best_idle(p);
+}
+
+/*
+ * The cpu cache locality difference between CPUs is used to determine how far
+ * to offset the virtual deadline. "One" difference in locality means that one
+ * timeslice difference is allowed longer for the cpu local tasks. This is
+ * enough in the common case when tasks are up to 2* number of CPUs to keep
+ * tasks within their shared cache CPUs only. CPUs on different nodes or not
+ * even in this domain (NUMA) have "3" difference, allowing 4 times longer
+ * deadlines before being taken onto another cpu, allowing for 2* the double
+ * seen by separate CPUs above.
+ * Simple summary: Virtual deadlines are equal on shared cache CPUs, double
+ * on separate CPUs and quadruple in separate NUMA nodes.
+ */
+static inline int
+cache_distance(struct rq *task_rq, struct rq *rq, struct task_struct *p)
+{
+ /* Check rq->last_task hasn't been dereferenced */
+ if (likely(rq->last_task)) {
+ if (rq->last_task == p)
+ return 0;
+ }
+ return rq->cpu_locality[cpu_of(task_rq)] * task_timeslice(p);
+}
+#else /* CONFIG_SMP */
+static inline void inc_qnr(void)
+{
+}
+
+static inline void dec_qnr(void)
+{
+}
+
+static inline int queued_notrunning(void)
+{
+ return grq.nr_running;
+}
+
+static inline void set_cpuidle_map(unsigned long cpu)
+{
+}
+
+static inline void clear_cpuidle_map(unsigned long cpu)
+{
+}
+
+static inline int suitable_idle_cpus(struct task_struct *p)
+{
+ return uprq->curr == uprq->idle;
+}
+
+static inline void resched_suitable_idle(struct task_struct *p)
+{
+}
+
+static inline int
+cache_distance(struct rq *task_rq, struct rq *rq, struct task_struct *p)
+{
+ return 0;
+}
+
+static inline void set_last_task(struct rq *rq, struct task_struct *p)
+{
+}
+#endif /* CONFIG_SMP */
+
+/*
+ * activate_idle_task - move idle task to the _front_ of runqueue.
+ */
+static inline void activate_idle_task(struct task_struct *p)
+{
+ enqueue_task_head(p);
+ grq.nr_running++;
+ inc_qnr();
+}
+
+static inline int normal_prio(struct task_struct *p)
+{
+ if (has_rt_policy(p))
+ return MAX_RT_PRIO - 1 - p->rt_priority;
+ if (idleprio_task(p))
+ return IDLE_PRIO;
+ if (iso_task(p))
+ return ISO_PRIO;
+ return NORMAL_PRIO;
+}
+
+/*
+ * Calculate the current priority, i.e. the priority
+ * taken into account by the scheduler. This value might
+ * be boosted by RT tasks as it will be RT if the task got
+ * RT-boosted. If not then it returns p->normal_prio.
+ */
+static int effective_prio(struct task_struct *p)
+{
+ p->normal_prio = normal_prio(p);
+ /*
+ * If we are RT tasks or we were boosted to RT priority,
+ * keep the priority unchanged. Otherwise, update priority
+ * to the normal priority:
+ */
+ if (!rt_prio(p->prio))
+ return p->normal_prio;
+ return p->prio;
+}
+
+/*
+ * activate_task - move a task to the runqueue. Enter with grq locked.
+ */
+static void activate_task(struct task_struct *p, struct rq *rq)
+{
+ update_clocks(rq);
+
+ /*
+ * Sleep time is in units of nanosecs, so shift by 20 to get a
+ * milliseconds-range estimation of the amount of time that the task
+ * spent sleeping:
+ */
+ if (unlikely(prof_on == SLEEP_PROFILING)) {
+ if (p->state == TASK_UNINTERRUPTIBLE)
+ profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
+ (rq->clock - p->last_ran) >> 20);
+ }
+
+ p->prio = effective_prio(p);
+ if (task_contributes_to_load(p))
+ grq.nr_uninterruptible--;
+ enqueue_task(p);
+ grq.nr_running++;
+ inc_qnr();
+}
+
+/*
+ * deactivate_task - If it's running, it's not on the grq and we can just
+ * decrement the nr_running. Enter with grq locked.
+ */
+static inline void deactivate_task(struct task_struct *p)
+{
+ if (task_contributes_to_load(p))
+ grq.nr_uninterruptible++;
+ grq.nr_running--;
+}
+
+#ifdef CONFIG_SMP
+void set_task_cpu(struct task_struct *p, unsigned int cpu)
+{
+ int old_cpu = task_cpu(p);
+
+ trace_sched_migrate_task(p, cpu);
+ if (old_cpu != cpu)
+ perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0);
+
+ /*
+ * After ->cpu is set up to a new value, task_grq_lock(p, ...) can be
+ * successfuly executed on another CPU. We must ensure that updates of
+ * per-task data have been completed by this moment.
+ */
+ smp_wmb();
+ task_thread_info(p)->cpu = cpu;
+}
+#endif
+
+/*
+ * Move a task off the global queue and take it to a cpu for it will
+ * become the running task.
+ */
+static inline void take_task(struct rq *rq, struct task_struct *p)
+{
+ set_task_cpu(p, cpu_of(rq));
+ dequeue_task(p);
+ dec_qnr();
+}
+
+/*
+ * Returns a descheduling task to the grq runqueue unless it is being
+ * deactivated.
+ */
+static inline void return_task(struct task_struct *p, int deactivate)
+{
+ if (deactivate)
+ deactivate_task(p);
+ else {
+ inc_qnr();
+ enqueue_task(p);
+ }
+}
+
+/*
+ * resched_task - mark a task 'to be rescheduled now'.
+ *
+ * On UP this means the setting of the need_resched flag, on SMP it
+ * might also involve a cross-CPU call to trigger the scheduler on
+ * the target CPU.
+ */
+#ifdef CONFIG_SMP
+
+#ifndef tsk_is_polling
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+#endif
+
+static void resched_task(struct task_struct *p)
+{
+ int cpu;
+
+ assert_spin_locked(&grq.lock);
+
+ if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+ return;
+
+ set_tsk_thread_flag(p, TIF_NEED_RESCHED);
+
+ cpu = task_cpu(p);
+ if (cpu == smp_processor_id())
+ return;
+
+ /* NEED_RESCHED must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(p))
+ smp_send_reschedule(cpu);
+}
+
+#else
+static inline void resched_task(struct task_struct *p)
+{
+ assert_spin_locked(&grq.lock);
+ set_tsk_need_resched(p);
+}
+#endif
+
+/**
+ * task_curr - is this task currently executing on a CPU?
+ * @p: the task in question.
+ */
+inline int task_curr(const struct task_struct *p)
+{
+ return cpu_curr(task_cpu(p)) == p;
+}
+
+#ifdef CONFIG_SMP
+struct migration_req {
+ struct list_head list;
+
+ struct task_struct *task;
+ int dest_cpu;
+
+ struct completion done;
+};
+
+/*
+ * wait_task_context_switch - wait for a thread to complete at least one
+ * context switch.
+ *
+ * @p must not be current.
+ */
+void wait_task_context_switch(struct task_struct *p)
+{
+ unsigned long nvcsw, nivcsw, flags;
+ int running;
+ struct rq *rq;
+
+ nvcsw = p->nvcsw;
+ nivcsw = p->nivcsw;
+ for (;;) {
+ /*
+ * The runqueue is assigned before the actual context
+ * switch. We need to take the runqueue lock.
+ *
+ * We could check initially without the lock but it is
+ * very likely that we need to take the lock in every
+ * iteration.
+ */
+ rq = task_grq_lock(p, &flags);
+ running = task_running(p);
+ task_grq_unlock(&flags);
+
+ if (likely(!running))
+ break;
+ /*
+ * The switch count is incremented before the actual
+ * context switch. We thus wait for two switches to be
+ * sure at least one completed.
+ */
+ if ((p->nvcsw - nvcsw) > 1)
+ break;
+ if ((p->nivcsw - nivcsw) > 1)
+ break;
+
+ cpu_relax();
+ }
+}
+
+/*
+ * wait_task_inactive - wait for a thread to unschedule.
+ *
+ * If @match_state is nonzero, it's the @p->state value just checked and
+ * not expected to change. If it changes, i.e. @p might have woken up,
+ * then return zero. When we succeed in waiting for @p to be off its CPU,
+ * we return a positive number (its total switch count). If a second call
+ * a short while later returns the same number, the caller can be sure that
+ * @p has remained unscheduled the whole time.
+ *
+ * The caller must ensure that the task *will* unschedule sometime soon,
+ * else this function might spin for a *long* time. This function can't
+ * be called with interrupts off, or it may introduce deadlock with
+ * smp_call_function() if an IPI is sent by the same process we are
+ * waiting to become inactive.
+ */
+unsigned long wait_task_inactive(struct task_struct *p, long match_state)
+{
+ unsigned long flags;
+ int running, on_rq;
+ unsigned long ncsw;
+ struct rq *rq;
+
+ for (;;) {
+ /*
+ * We do the initial early heuristics without holding
+ * any task-queue locks at all. We'll only try to get
+ * the runqueue lock when things look like they will
+ * work out! In the unlikely event rq is dereferenced
+ * since we're lockless, grab it again.
+ */
+#ifdef CONFIG_SMP
+retry_rq:
+ rq = task_rq(p);
+ if (unlikely(!rq))
+ goto retry_rq;
+#else /* CONFIG_SMP */
+ rq = task_rq(p);
+#endif
+ /*
+ * If the task is actively running on another CPU
+ * still, just relax and busy-wait without holding
+ * any locks.
+ *
+ * NOTE! Since we don't hold any locks, it's not
+ * even sure that "rq" stays as the right runqueue!
+ * But we don't care, since this will return false
+ * if the runqueue has changed and p is actually now
+ * running somewhere else!
+ */
+ while (task_running(p) && p == rq->curr) {
+ if (match_state && unlikely(p->state != match_state))
+ return 0;
+ cpu_relax();
+ }
+
+ /*
+ * Ok, time to look more closely! We need the grq
+ * lock now, to be *sure*. If we're wrong, we'll
+ * just go back and repeat.
+ */
+ rq = task_grq_lock(p, &flags);
+ trace_sched_wait_task(rq, p);
+ running = task_running(p);
+ on_rq = task_queued(p);
+ ncsw = 0;
+ if (!match_state || p->state == match_state)
+ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
+ task_grq_unlock(&flags);
+
+ /*
+ * If it changed from the expected state, bail out now.
+ */
+ if (unlikely(!ncsw))
+ break;
+
+ /*
+ * Was it really running after all now that we
+ * checked with the proper locks actually held?
+ *
+ * Oops. Go back and try again..
+ */
+ if (unlikely(running)) {
+ cpu_relax();
+ continue;
+ }
+
+ /*
+ * It's not enough that it's not actively running,
+ * it must be off the runqueue _entirely_, and not
+ * preempted!
+ *
+ * So if it was still runnable (but just not actively
+ * running right now), it's preempted, and we should
+ * yield - it could be a while.
+ */
+ if (unlikely(on_rq)) {
+ schedule_timeout_uninterruptible(1);
+ continue;
+ }
+
+ /*
+ * Ahh, all good. It wasn't running, and it wasn't
+ * runnable, which means that it will never become
+ * running in the future either. We're all done!
+ */
+ break;
+ }
+
+ return ncsw;
+}
+
+/***
+ * kick_process - kick a running thread to enter/exit the kernel
+ * @p: the to-be-kicked thread
+ *
+ * Cause a process which is running on another CPU to enter
+ * kernel-mode, without any delay. (to get signals handled.)
+ *
+ * NOTE: this function doesnt have to take the runqueue lock,
+ * because all it wants to ensure is that the remote task enters
+ * the kernel. If the IPI races and the task has been migrated
+ * to another CPU then no harm is done and the purpose has been
+ * achieved as well.
+ */
+void kick_process(struct task_struct *p)
+{
+ int cpu;
+
+ preempt_disable();
+ cpu = task_cpu(p);
+ if ((cpu != smp_processor_id()) && task_curr(p))
+ smp_send_reschedule(cpu);
+ preempt_enable();
+}
+EXPORT_SYMBOL_GPL(kick_process);
+#endif
+
+/**
+ * kthread_bind - bind a just-created kthread to a cpu.
+ * @p: thread created by kthread_create().
+ * @cpu: cpu (might not be online, must be possible) for @k to run on.
+ *
+ * Description: This function is equivalent to set_cpus_allowed(),
+ * except that @cpu doesn't need to be online, and the thread must be
+ * stopped (i.e., just returned from kthread_create()).
+ *
+ * Function lives here instead of kthread.c because it messes with
+ * scheduler internals which require locking.
+ */
+void kthread_bind(struct task_struct *p, unsigned int cpu)
+ {
+ unsigned long flags;
+
+ /* Must have done schedule() in kthread() before we set_task_cpu */
+ if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
+ WARN_ON(1);
+ return;
+ }
+
+ grq_lock_irqsave(&flags);
+ set_task_cpu(p, cpu);
+ p->cpus_allowed = cpumask_of_cpu(cpu);
+ p->flags |= PF_THREAD_BOUND;
+ grq_unlock_irqrestore(&flags);
+}
+EXPORT_SYMBOL(kthread_bind);
+
+#define rq_idle(rq) ((rq)->rq_prio == PRIO_LIMIT)
+
+/*
+ * RT tasks preempt purely on priority. SCHED_NORMAL tasks preempt on the
+ * basis of earlier deadlines. SCHED_IDLEPRIO don't preempt anything else or
+ * between themselves, they cooperatively multitask. An idle rq scores as
+ * prio PRIO_LIMIT so it is always preempted.
+ */
+static inline int
+can_preempt(struct task_struct *p, int prio, u64 deadline,
+ unsigned int policy)
+{
+ /* Better static priority RT task or better policy preemption */
+ if (p->prio < prio)
+ return 1;
+ if (p->prio > prio)
+ return 0;
+ /* SCHED_NORMAL, BATCH and ISO will preempt based on deadline */
+ if (!deadline_before(p->deadline, deadline))
+ return 0;
+ return 1;
+}
+#ifdef CONFIG_SMP
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Check to see if there is a task that is affined only to offline CPUs but
+ * still wants runtime. This happens to kernel threads during suspend/halt and
+ * disabling of CPUs.
+ */
+static inline int online_cpus(struct task_struct *p)
+{
+ return (likely(cpus_intersects(cpu_online_map, p->cpus_allowed)));
+}
+#else /* CONFIG_HOTPLUG_CPU */
+/* All available CPUs are always online without hotplug. */
+static inline int online_cpus(struct task_struct *p)
+{
+ return 1;
+}
+#endif
+
+
+/*
+ * Check to see if p can run on cpu, and if not, whether there are any online
+ * CPUs it can run on instead.
+ */
+static inline int needs_other_cpu(struct task_struct *p, int cpu)
+{
+ if (unlikely(!cpu_isset(cpu, p->cpus_allowed) && online_cpus(p)))
+ return 1;
+ return 0;
+}
+
+/*
+ * latest_deadline and highest_prio_rq are initialised only to silence the
+ * compiler. When all else is equal, still prefer this_rq.
+ */
+static void try_preempt(struct task_struct *p, struct rq *this_rq)
+{
+ struct rq *highest_prio_rq = this_rq;
+ u64 latest_deadline;
+ unsigned long cpu;
+ int highest_prio;
+ cpumask_t tmp;
+
+ /* IDLEPRIO tasks never preempt anything */
+ if (p->policy == SCHED_IDLEPRIO)
+ return;
+
+ if (suitable_idle_cpus(p)) {
+ resched_best_idle(p);
+ return;
+ }
+
+ if (online_cpus(p))
+ cpus_and(tmp, cpu_online_map, p->cpus_allowed);
+ else
+ (cpumask_copy(&tmp, &cpu_online_map));
+
+ latest_deadline = 0;
+ highest_prio = -1;
+
+ for_each_cpu_mask(cpu, tmp) {
+ u64 offset_deadline;
+ struct rq *rq;
+ int rq_prio;
+
+ rq = cpu_rq(cpu);
+ rq_prio = rq->rq_prio;
+ if (rq_prio < highest_prio)
+ continue;
+
+ offset_deadline = rq->rq_deadline -
+ cache_distance(this_rq, rq, p);
+
+ if (rq_prio > highest_prio || (rq_prio == highest_prio &&
+ deadline_after(offset_deadline, latest_deadline))) {
+ latest_deadline = offset_deadline;
+ highest_prio = rq_prio;
+ highest_prio_rq = rq;
+ }
+ }
+
+ if (!can_preempt(p, highest_prio, highest_prio_rq->rq_deadline,
+ highest_prio_rq->rq_policy))
+ return;
+
+ resched_task(highest_prio_rq->curr);
+}
+#else /* CONFIG_SMP */
+static inline int needs_other_cpu(struct task_struct *p, int cpu)
+{
+ return 0;
+}
+
+static void try_preempt(struct task_struct *p, struct rq *this_rq)
+{
+ if (p->policy == SCHED_IDLEPRIO)
+ return;
+ if (can_preempt(p, uprq->rq_prio, uprq->rq_deadline,
+ uprq->rq_policy))
+ resched_task(uprq->curr);
+}
+#endif /* CONFIG_SMP */
+
+/**
+ * task_oncpu_function_call - call a function on the cpu on which a task runs
+ * @p: the task to evaluate
+ * @func: the function to be called
+ * @info: the function call argument
+ *
+ * Calls the function @func when the task is currently running. This might
+ * be on the current CPU, which just calls the function directly
+ */
+void task_oncpu_function_call(struct task_struct *p,
+ void (*func) (void *info), void *info)
+{
+ int cpu;
+
+ preempt_disable();
+ cpu = task_cpu(p);
+ if (task_curr(p))
+ smp_call_function_single(cpu, func, info, 1);
+ preempt_enable();
+}
+
+/***
+ * try_to_wake_up - wake up a thread
+ * @p: the to-be-woken-up thread
+ * @state: the mask of task states that can be woken
+ * @sync: do a synchronous wakeup?
+ *
+ * Put it on the run-queue if it's not already there. The "current"
+ * thread is always on the run-queue (except when the actual
+ * re-schedule is in progress), and as such you're allowed to do
+ * the simpler "current->state = TASK_RUNNING" to mark yourself
+ * runnable without the overhead of this.
+ *
+ * returns failure only if the task is already active.
+ */
+static int try_to_wake_up(struct task_struct *p, unsigned int state,
+ int wake_flags)
+{
+ int sync, success = 0;
+ unsigned long flags;
+ struct rq *rq;
+
+ get_cpu();
+
+ /* This barrier is undocumented, probably for p->state? くそ */
+ smp_wmb();
+
+ /*
+ * No need to do time_lock_grq as we only need to update the rq clock
+ * if we activate the task
+ */
+ rq = task_grq_lock(p, &flags);
+
+ /* state is a volatile long, どうして、分からない */
+ if (!((unsigned int)p->state & state))
+ goto out_unlock;
+
+ if (task_queued(p) || task_running(p))
+ goto out_running;
+
+ activate_task(p, rq);
+ sync = wake_flags & WF_SYNC;
+
+ /*
+ * Sync wakeups (i.e. those types of wakeups where the waker
+ * has indicated that it will leave the CPU in short order)
+ * don't trigger a preemption if there are no idle cpus,
+ * instead waiting for current to deschedule.
+ */
+ if (!sync || suitable_idle_cpus(p))
+ try_preempt(p, rq);
+ success = 1;
+
+out_running:
+ trace_sched_wakeup(rq, p, success);
+ p->state = TASK_RUNNING;
+out_unlock:
+ task_grq_unlock(&flags);
+ put_cpu();
+
+ return success;
+}
+
+/**
+ * wake_up_process - Wake up a specific process
+ * @p: The process to be woken up.
+ *
+ * Attempt to wake up the nominated process and move it to the set of runnable
+ * processes. Returns 1 if the process was woken up, 0 if it was already
+ * running.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+int wake_up_process(struct task_struct *p)
+{
+ return try_to_wake_up(p, TASK_ALL, 0);
+}
+EXPORT_SYMBOL(wake_up_process);
+
+int wake_up_state(struct task_struct *p, unsigned int state)
+{
+ return try_to_wake_up(p, state, 0);
+}
+
+static void time_slice_expired(struct task_struct *p);
+
+/*
+ * Perform scheduler related setup for a newly forked process p.
+ * p is forked by current.
+ */
+void sched_fork(struct task_struct *p, int clone_flags)
+{
+ struct task_struct *curr;
+ int cpu = get_cpu();
+ struct rq *rq;
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+ INIT_HLIST_HEAD(&p->preempt_notifiers);
+#endif
+ /*
+ * We mark the process as running here, but have not actually
+ * inserted it onto the runqueue yet. This guarantees that
+ * nobody will actually run it, and a signal or other external
+ * event cannot wake it up and insert it on the runqueue either.
+ */
+ p->state = TASK_RUNNING;
+ set_task_cpu(p, cpu);
+
+ /* Should be reset in fork.c but done here for ease of bfs patching */
+ p->sched_time = p->stime_pc = p->utime_pc = 0;
+
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) {
+ p->policy = SCHED_NORMAL;
+ p->normal_prio = normal_prio(p);
+ }
+
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ p->normal_prio = p->static_prio;
+ }
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
+
+ curr = current;
+ /*
+ * Make sure we do not leak PI boosting priority to the child.
+ */
+ p->prio = curr->normal_prio;
+
+ INIT_LIST_HEAD(&p->run_list);
+#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
+ if (unlikely(sched_info_on()))
+ memset(&p->sched_info, 0, sizeof(p->sched_info));
+#endif
+
+ p->oncpu = 0;
+
+#ifdef CONFIG_PREEMPT
+ /* Want to start with kernel preemption disabled. */
+ task_thread_info(p)->preempt_count = 1;
+#endif
+ if (unlikely(p->policy == SCHED_FIFO))
+ goto out;
+ /*
+ * Share the timeslice between parent and child, thus the
+ * total amount of pending timeslices in the system doesn't change,
+ * resulting in more scheduling fairness. If it's negative, it won't
+ * matter since that's the same as being 0. current's time_slice is
+ * actually in rq_time_slice when it's running, as is its last_ran
+ * value. rq->rq_deadline is only modified within schedule() so it
+ * is always equal to current->deadline.
+ */
+ rq = task_grq_lock_irq(curr);
+ if (likely(rq->rq_time_slice >= RESCHED_US * 2)) {
+ rq->rq_time_slice /= 2;
+ p->time_slice = rq->rq_time_slice;
+ } else {
+ /*
+ * Forking task has run out of timeslice. Reschedule it and
+ * start its child with a new time slice and deadline. The
+ * child will end up running first because its deadline will
+ * be slightly earlier.
+ */
+ rq->rq_time_slice = 0;
+ set_tsk_need_resched(curr);
+ time_slice_expired(p);
+ }
+ p->last_ran = rq->rq_last_ran;
+ task_grq_unlock_irq();
+out:
+ put_cpu();
+}
+
+/*
+ * wake_up_new_task - wake up a newly created task for the first time.
+ *
+ * This function will do some initial scheduler statistics housekeeping
+ * that must be done for every newly created context, then puts the task
+ * on the runqueue and wakes it.
+ */
+void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
+{
+ struct task_struct *parent;
+ unsigned long flags;
+ struct rq *rq;
+
+ rq = task_grq_lock(p, &flags); ;
+ p->state = TASK_RUNNING;
+ parent = p->parent;
+ /* Unnecessary but small chance that the parent changed CPU */
+ set_task_cpu(p, task_cpu(parent));
+ activate_task(p, rq);
+ trace_sched_wakeup_new(rq, p, 1);
+ if (!(clone_flags & CLONE_VM) && rq->curr == parent &&
+ !suitable_idle_cpus(p)) {
+ /*
+ * The VM isn't cloned, so we're in a good position to
+ * do child-runs-first in anticipation of an exec. This
+ * usually avoids a lot of COW overhead.
+ */
+ resched_task(parent);
+ } else
+ try_preempt(p, rq);
+ task_grq_unlock(&flags);
+}
+
+/* Nothing to do here */
+void sched_exit(struct task_struct *p)
+{
+}
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+
+/**
+ * preempt_notifier_register - tell me when current is being preempted & rescheduled
+ * @notifier: notifier struct to register
+ */
+void preempt_notifier_register(struct preempt_notifier *notifier)
+{
+ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers);
+}
+EXPORT_SYMBOL_GPL(preempt_notifier_register);
+
+/**
+ * preempt_notifier_unregister - no longer interested in preemption notifications
+ * @notifier: notifier struct to unregister
+ *
+ * This is safe to call from within a preemption notifier.
+ */
+void preempt_notifier_unregister(struct preempt_notifier *notifier)
+{
+ hlist_del(¬ifier->link);
+}
+EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
+
+static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+ struct preempt_notifier *notifier;
+ struct hlist_node *node;
+
+ hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+ notifier->ops->sched_in(notifier, raw_smp_processor_id());
+}
+
+static void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
+{
+ struct preempt_notifier *notifier;
+ struct hlist_node *node;
+
+ hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+ notifier->ops->sched_out(notifier, next);
+}
+
+#else /* !CONFIG_PREEMPT_NOTIFIERS */
+
+static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+}
+
+static void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
+{
+}
+
+#endif /* CONFIG_PREEMPT_NOTIFIERS */
+
+/**
+ * prepare_task_switch - prepare to switch tasks
+ * @rq: the runqueue preparing to switch
+ * @next: the task we are going to switch to.
+ *
+ * This is called with the rq lock held and interrupts off. It must
+ * be paired with a subsequent finish_task_switch after the context
+ * switch.
+ *
+ * prepare_task_switch sets up locking and calls architecture specific
+ * hooks.
+ */
+static inline void
+prepare_task_switch(struct rq *rq, struct task_struct *prev,
+ struct task_struct *next)
+{
+ fire_sched_out_preempt_notifiers(prev, next);
+ prepare_lock_switch(rq, next);
+ prepare_arch_switch(next);
+}
+
+/**
+ * finish_task_switch - clean up after a task-switch
+ * @rq: runqueue associated with task-switch
+ * @prev: the thread we just switched away from.
+ *
+ * finish_task_switch must be called after the context switch, paired
+ * with a prepare_task_switch call before the context switch.
+ * finish_task_switch will reconcile locking set up by prepare_task_switch,
+ * and do any other architecture-specific cleanup actions.
+ *
+ * Note that we may have delayed dropping an mm in context_switch(). If
+ * so, we finish that here outside of the runqueue lock. (Doing it
+ * with the lock held can cause deadlocks; see schedule() for
+ * details.)
+ */
+static inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
+ __releases(grq.lock)
+{
+ struct mm_struct *mm = rq->prev_mm;
+ long prev_state;
+
+ rq->prev_mm = NULL;
+
+ /*
+ * A task struct has one reference for the use as "current".
+ * If a task dies, then it sets TASK_DEAD in tsk->state and calls
+ * schedule one last time. The schedule call will never return, and
+ * the scheduled task must drop that reference.
+ * The test for TASK_DEAD must occur while the runqueue locks are
+ * still held, otherwise prev could be scheduled on another cpu, die
+ * there before we look at prev->state, and then the reference would
+ * be dropped twice.
+ * Manfred Spraul <manfred@colorfullife.com>
+ */
+ prev_state = prev->state;
+ finish_arch_switch(prev);
+ perf_event_task_sched_in(current, cpu_of(rq));
+ finish_lock_switch(rq, prev);
+
+ fire_sched_in_preempt_notifiers(current);
+ if (mm)
+ mmdrop(mm);
+ if (unlikely(prev_state == TASK_DEAD)) {
+ /*
+ * Remove function-return probe instances associated with this
+ * task and put them back on the free list.
+ */
+ kprobe_flush_task(prev);
+ put_task_struct(prev);
+ }
+}
+
+/**
+ * schedule_tail - first thing a freshly forked thread must call.
+ * @prev: the thread we just switched away from.
+ */
+asmlinkage void schedule_tail(struct task_struct *prev)
+ __releases(grq.lock)
+{
+ struct rq *rq = this_rq();
+
+ finish_task_switch(rq, prev);
+#ifdef __ARCH_WANT_UNLOCKED_CTXSW
+ /* In this case, finish_task_switch does not reenable preemption */
+ preempt_enable();
+#endif
+ if (current->set_child_tid)
+ put_user(current->pid, current->set_child_tid);
+}
+
+/*
+ * context_switch - switch to the new MM and the new
+ * thread's register state.
+ */
+static inline void
+context_switch(struct rq *rq, struct task_struct *prev,
+ struct task_struct *next)
+{
+ struct mm_struct *mm, *oldmm;
+
+ prepare_task_switch(rq, prev, next);
+ trace_sched_switch(rq, prev, next);
+ mm = next->mm;
+ oldmm = prev->active_mm;
+ /*
+ * For paravirt, this is coupled with an exit in switch_to to
+ * combine the page table reload and the switch backend into
+ * one hypercall.
+ */
+ arch_start_context_switch(prev);
+
+ if (unlikely(!mm)) {
+ next->active_mm = oldmm;
+ atomic_inc(&oldmm->mm_count);
+ enter_lazy_tlb(oldmm, next);
+ } else
+ switch_mm(oldmm, mm, next);
+
+ if (unlikely(!prev->mm)) {
+ prev->active_mm = NULL;
+ rq->prev_mm = oldmm;
+ }
+ /*
+ * Since the runqueue lock will be released by the next
+ * task (which is an invalid locking op but in the case
+ * of the scheduler it's an obvious special-case), so we
+ * do an early lockdep release here:
+ */
+#ifndef __ARCH_WANT_UNLOCKED_CTXSW
+ spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
+#endif
+
+ /* Here we just switch the register state and the stack. */
+ switch_to(prev, next, prev);
+
+ barrier();
+ /*
+ * this_rq must be evaluated again because prev may have moved
+ * CPUs since it called schedule(), thus the 'rq' on its stack
+ * frame will be invalid.
+ */
+ finish_task_switch(this_rq(), prev);
+}
+
+/*
+ * nr_running, nr_uninterruptible and nr_context_switches:
+ *
+ * externally visible scheduler statistics: current number of runnable
+ * threads, current number of uninterruptible-sleeping threads, total
+ * number of context switches performed since bootup. All are measured
+ * without grabbing the grq lock but the occasional inaccurate result
+ * doesn't matter so long as it's positive.
+ */
+unsigned long nr_running(void)
+{
+ long nr = grq.nr_running;
+
+ if (unlikely(nr < 0))
+ nr = 0;
+ return (unsigned long)nr;
+}
+
+unsigned long nr_uninterruptible(void)
+{
+ long nu = grq.nr_uninterruptible;
+
+ if (unlikely(nu < 0))
+ nu = 0;
+ return nu;
+}
+
+unsigned long long nr_context_switches(void)
+{
+ long long ns = grq.nr_switches;
+
+ /* This is of course impossible */
+ if (unlikely(ns < 0))
+ ns = 1;
+ return (long long)ns;
+}
+
+unsigned long nr_iowait(void)
+{
+ unsigned long i, sum = 0;
+
+ for_each_possible_cpu(i)
+ sum += atomic_read(&cpu_rq(i)->nr_iowait);
+
+ return sum;
+}
+
+unsigned long nr_iowait_cpu(void)
+{
+ struct rq *this = this_rq();
+ return atomic_read(&this->nr_iowait);
+}
+
+unsigned long nr_active(void)
+{
+ return nr_running() + nr_uninterruptible();
+}
+
+/* Beyond a task running on this CPU, load is equal everywhere on BFS */
+unsigned long this_cpu_load(void)
+{
+ return this_rq()->rq_running +
+ (queued_notrunning() + nr_uninterruptible()) /
+ (1 + num_online_cpus());
+}
+
+/* Variables and functions for calc_load */
+static unsigned long calc_load_update;
+unsigned long avenrun[3];
+EXPORT_SYMBOL(avenrun);
+
+/**
+ * get_avenrun - get the load average array
+ * @loads: pointer to dest load array
+ * @offset: offset to add
+ * @shift: shift count to shift the result left
+ *
+ * These values are estimates at best, so no need for locking.
+ */
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
+{
+ loads[0] = (avenrun[0] + offset) << shift;
+ loads[1] = (avenrun[1] + offset) << shift;
+ loads[2] = (avenrun[2] + offset) << shift;
+}
+
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+ load *= exp;
+ load += active * (FIXED_1 - exp);
+ return load >> FSHIFT;
+}
+
+/*
+ * calc_load - update the avenrun load estimates every LOAD_FREQ seconds.
+ */
+void calc_global_load(void)
+{
+ long active;
+
+ if (time_before(jiffies, calc_load_update))
+ return;
+ active = nr_active() * FIXED_1;
+
+ avenrun[0] = calc_load(avenrun[0], EXP_1, active);
+ avenrun[1] = calc_load(avenrun[1], EXP_5, active);
+ avenrun[2] = calc_load(avenrun[2], EXP_15, active);
+
+ calc_load_update = jiffies + LOAD_FREQ;
+}
+
+DEFINE_PER_CPU(struct kernel_stat, kstat);
+
+EXPORT_PER_CPU_SYMBOL(kstat);
+
+/*
+ * On each tick, see what percentage of that tick was attributed to each
+ * component and add the percentage to the _pc values. Once a _pc value has
+ * accumulated one tick's worth, account for that. This means the total
+ * percentage of load components will always be 100 per tick.
+ */
+static void pc_idle_time(struct rq *rq, unsigned long pc)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
+
+ if (atomic_read(&rq->nr_iowait) > 0) {
+ rq->iowait_pc += pc;
+ if (rq->iowait_pc >= 100) {
+ rq->iowait_pc %= 100;
+ cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
+ }
+ } else {
+ rq->idle_pc += pc;
+ if (rq->idle_pc >= 100) {
+ rq->idle_pc %= 100;
+ cpustat->idle = cputime64_add(cpustat->idle, tmp);
+ }
+ }
+}
+
+static void
+pc_system_time(struct rq *rq, struct task_struct *p, int hardirq_offset,
+ unsigned long pc, unsigned long ns)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
+ cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
+
+ p->stime_pc += pc;
+ if (p->stime_pc >= 100) {
+ p->stime_pc -= 100;
+ p->stime = cputime_add(p->stime, cputime_one_jiffy);
+ p->stimescaled = cputime_add(p->stimescaled, one_jiffy_scaled);
+ account_group_system_time(p, cputime_one_jiffy);
+ acct_update_integrals(p);
+ }
+ p->sched_time += ns;
+
+ if (hardirq_count() - hardirq_offset)
+ rq->irq_pc += pc;
+ else if (softirq_count()) {
+ rq->softirq_pc += pc;
+ if (rq->softirq_pc >= 100) {
+ rq->softirq_pc %= 100;
+ cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
+ }
+ } else {
+ rq->system_pc += pc;
+ if (rq->system_pc >= 100) {
+ rq->system_pc %= 100;
+ cpustat->system = cputime64_add(cpustat->system, tmp);
+ }
+ }
+}
+
+static void pc_user_time(struct rq *rq, struct task_struct *p,
+ unsigned long pc, unsigned long ns)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
+ cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
+
+ p->utime_pc += pc;
+ if (p->utime_pc >= 100) {
+ p->utime_pc -= 100;
+ p->utime = cputime_add(p->utime, cputime_one_jiffy);
+ p->utimescaled = cputime_add(p->utimescaled, one_jiffy_scaled);
+ account_group_user_time(p, cputime_one_jiffy);
+ acct_update_integrals(p);
+ }
+ p->sched_time += ns;
+
+ if (TASK_NICE(p) > 0 || idleprio_task(p)) {
+ rq->nice_pc += pc;
+ if (rq->nice_pc >= 100) {
+ rq->nice_pc %= 100;
+ cpustat->nice = cputime64_add(cpustat->nice, tmp);
+ }
+ } else {
+ rq->user_pc += pc;
+ if (rq->user_pc >= 100) {
+ rq->user_pc %= 100;
+ cpustat->user = cputime64_add(cpustat->user, tmp);
+ }
+ }
+}
+
+/* Convert nanoseconds to percentage of one tick. */
+#define NS_TO_PC(NS) (NS * 100 / JIFFY_NS)
+
+/*
+ * This is called on clock ticks and on context switches.
+ * Bank in p->sched_time the ns elapsed since the last tick or switch.
+ * CPU scheduler quota accounting is also performed here in microseconds.
+ */
+static void
+update_cpu_clock(struct rq *rq, struct task_struct *p, int tick)
+{
+ long account_ns = rq->clock - rq->timekeep_clock;
+ struct task_struct *idle = rq->idle;
+ unsigned long account_pc;
+
+ if (unlikely(account_ns < 0))
+ account_ns = 0;
+
+ account_pc = NS_TO_PC(account_ns);
+
+ if (tick) {
+ int user_tick = user_mode(get_irq_regs());
+
+ /* Accurate tick timekeeping */
+ if (user_tick)
+ pc_user_time(rq, p, account_pc, account_ns);
+ else if (p != idle || (irq_count() != HARDIRQ_OFFSET))
+ pc_system_time(rq, p, HARDIRQ_OFFSET,
+ account_pc, account_ns);
+ else
+ pc_idle_time(rq, account_pc);
+ } else {
+ /* Accurate subtick timekeeping */
+ if (p == idle)
+ pc_idle_time(rq, account_pc);
+ else
+ pc_user_time(rq, p, account_pc, account_ns);
+ }
+
+ /* time_slice accounting is done in usecs to avoid overflow on 32bit */
+ if (rq->rq_policy != SCHED_FIFO && p != idle) {
+ s64 time_diff = rq->clock - rq->rq_last_ran;
+
+ niffy_diff(&time_diff, 1);
+ rq->rq_time_slice -= NS_TO_US(time_diff);
+ }
+ rq->rq_last_ran = rq->timekeep_clock = rq->clock;
+}
+
+/*
+ * Return any ns on the sched_clock that have not yet been accounted in
+ * @p in case that task is currently running.
+ *
+ * Called with task_grq_lock() held.
+ */
+static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
+{
+ u64 ns = 0;
+
+ if (p == rq->curr) {
+ update_clocks(rq);
+ ns = rq->clock - rq->rq_last_ran;
+ if (unlikely((s64)ns < 0))
+ ns = 0;
+ }
+
+ return ns;
+}
+
+unsigned long long task_delta_exec(struct task_struct *p)
+{
+ unsigned long flags;
+ struct rq *rq;
+ u64 ns;
+
+ rq = task_grq_lock(p, &flags);
+ ns = do_task_delta_exec(p, rq);
+ task_grq_unlock(&flags);
+
+ return ns;
+}
+
+/*
+ * Return accounted runtime for the task.
+ * In case the task is currently running, return the runtime plus current's
+ * pending runtime that have not been accounted yet.
+ */
+unsigned long long task_sched_runtime(struct task_struct *p)
+{
+ unsigned long flags;
+ struct rq *rq;
+ u64 ns;
+
+ rq = task_grq_lock(p, &flags);
+ ns = p->sched_time + do_task_delta_exec(p, rq);
+ task_grq_unlock(&flags);
+
+ return ns;
+}
+
+/*
+ * Return sum_exec_runtime for the thread group.
+ * In case the task is currently running, return the sum plus current's
+ * pending runtime that have not been accounted yet.
+ *
+ * Note that the thread group might have other running tasks as well,
+ * so the return value not includes other pending runtime that other
+ * running tasks might have.
+ */
+unsigned long long thread_group_sched_runtime(struct task_struct *p)
+{
+ struct task_cputime totals;
+ unsigned long flags;
+ struct rq *rq;
+ u64 ns;
+
+ rq = task_grq_lock(p, &flags);
+ thread_group_cputime(p, &totals);
+ ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
+ task_grq_unlock(&flags);
+
+ return ns;
+}
+
+/* Compatibility crap for removal */
+void account_user_time(struct task_struct *p, cputime_t cputime,
+ cputime_t cputime_scaled)
+{
+}
+
+void account_idle_time(cputime_t cputime)
+{
+}
+
+/*
+ * Account guest cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in virtual machine since the last update
+ * @cputime_scaled: cputime scaled by cpu frequency
+ */
+static void account_guest_time(struct task_struct *p, cputime_t cputime,
+ cputime_t cputime_scaled)
+{
+ cputime64_t tmp;
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+
+ tmp = cputime_to_cputime64(cputime);
+
+ /* Add guest time to process. */
+ p->utime = cputime_add(p->utime, cputime);
+ p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
+ account_group_user_time(p, cputime);
+ p->gtime = cputime_add(p->gtime, cputime);
+
+ /* Add guest time to cpustat. */
+ cpustat->user = cputime64_add(cpustat->user, tmp);
+ cpustat->guest = cputime64_add(cpustat->guest, tmp);
+}
+
+/*
+ * Account system cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @hardirq_offset: the offset to subtract from hardirq_count()
+ * @cputime: the cpu time spent in kernel space since the last update
+ * @cputime_scaled: cputime scaled by cpu frequency
+ * This is for guest only now.
+ */
+void account_system_time(struct task_struct *p, int hardirq_offset,
+ cputime_t cputime, cputime_t cputime_scaled)
+{
+
+ if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
+ account_guest_time(p, cputime, cputime_scaled);
+}
+
+/*
+ * Account for involuntary wait time.
+ * @steal: the cpu time spent in involuntary wait
+ */
+void account_steal_time(cputime_t cputime)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ cputime64_t cputime64 = cputime_to_cputime64(cputime);
+
+ cpustat->steal = cputime64_add(cpustat->steal, cputime64);
+}
+
+/*
+ * Account for idle time.
+ * @cputime: the cpu time spent in idle wait
+ */
+static void account_idle_times(cputime_t cputime)
+{
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ cputime64_t cputime64 = cputime_to_cputime64(cputime);
+ struct rq *rq = this_rq();
+
+ if (atomic_read(&rq->nr_iowait) > 0)
+ cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
+ else
+ cpustat->idle = cputime64_add(cpustat->idle, cputime64);
+}
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+
+void account_process_tick(struct task_struct *p, int user_tick)
+{
+}
+
+/*
+ * Account multiple ticks of steal time.
+ * @p: the process from which the cpu time has been stolen
+ * @ticks: number of stolen ticks
+ */
+void account_steal_ticks(unsigned long ticks)
+{
+ account_steal_time(jiffies_to_cputime(ticks));
+}
+
+/*
+ * Account multiple ticks of idle time.
+ * @ticks: number of stolen ticks
+ */
+void account_idle_ticks(unsigned long ticks)
+{
+ account_idle_times(jiffies_to_cputime(ticks));
+}
+#endif
+
+static inline void grq_iso_lock(void)
+ __acquires(grq.iso_lock)
+{
+ spin_lock(&grq.iso_lock);
+}
+
+static inline void grq_iso_unlock(void)
+ __releases(grq.iso_lock)
+{
+ spin_unlock(&grq.iso_lock);
+}
+
+/*
+ * Functions to test for when SCHED_ISO tasks have used their allocated
+ * quota as real time scheduling and convert them back to SCHED_NORMAL.
+ * Where possible, the data is tested lockless, to avoid grabbing iso_lock
+ * because the occasional inaccurate result won't matter. However the
+ * tick data is only ever modified under lock. iso_refractory is only simply
+ * set to 0 or 1 so it's not worth grabbing the lock yet again for that.
+ */
+static void set_iso_refractory(void)
+{
+ grq.iso_refractory = 1;
+}
+
+static void clear_iso_refractory(void)
+{
+ grq.iso_refractory = 0;
+}
+
+/*
+ * Test if SCHED_ISO tasks have run longer than their alloted period as RT
+ * tasks and set the refractory flag if necessary. There is 10% hysteresis
+ * for unsetting the flag. 115/128 is ~90/100 as a fast shift instead of a
+ * slow division.
+ */
+static unsigned int test_ret_isorefractory(struct rq *rq)
+{
+ if (likely(!grq.iso_refractory)) {
+ if (grq.iso_ticks > ISO_PERIOD * sched_iso_cpu)
+ set_iso_refractory();
+ } else {
+ if (grq.iso_ticks < ISO_PERIOD * (sched_iso_cpu * 115 / 128))
+ clear_iso_refractory();
+ }
+ return grq.iso_refractory;
+}
+
+static void iso_tick(void)
+{
+ grq_iso_lock();
+ grq.iso_ticks += 100;
+ grq_iso_unlock();
+}
+
+/* No SCHED_ISO task was running so decrease rq->iso_ticks */
+static inline void no_iso_tick(void)
+{
+ if (grq.iso_ticks) {
+ grq_iso_lock();
+ grq.iso_ticks -= grq.iso_ticks / ISO_PERIOD + 1;
+ if (unlikely(grq.iso_refractory && grq.iso_ticks <
+ ISO_PERIOD * (sched_iso_cpu * 115 / 128)))
+ clear_iso_refractory();
+ grq_iso_unlock();
+ }
+}
+
+static int rq_running_iso(struct rq *rq)
+{
+ return rq->rq_prio == ISO_PRIO;
+}
+
+/* This manages tasks that have run out of timeslice during a scheduler_tick */
+static void task_running_tick(struct rq *rq)
+{
+ struct task_struct *p;
+
+ /*
+ * If a SCHED_ISO task is running we increment the iso_ticks. In
+ * order to prevent SCHED_ISO tasks from causing starvation in the
+ * presence of true RT tasks we account those as iso_ticks as well.
+ */
+ if ((rt_queue(rq) || (iso_queue(rq) && !grq.iso_refractory))) {
+ if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100)
+ iso_tick();
+ } else
+ no_iso_tick();
+
+ if (iso_queue(rq)) {
+ if (unlikely(test_ret_isorefractory(rq))) {
+ if (rq_running_iso(rq)) {
+ /*
+ * SCHED_ISO task is running as RT and limit
+ * has been hit. Force it to reschedule as
+ * SCHED_NORMAL by zeroing its time_slice
+ */
+ rq->rq_time_slice = 0;
+ }
+ }
+ }
+
+ /* SCHED_FIFO tasks never run out of timeslice. */
+ if (rq->rq_policy == SCHED_FIFO)
+ return;
+ /*
+ * Tasks that were scheduled in the first half of a tick are not
+ * allowed to run into the 2nd half of the next tick if they will
+ * run out of time slice in the interim. Otherwise, if they have
+ * less than 100us of time slice left they will be rescheduled.
+ */
+ if (rq->dither) {
+ if (rq->rq_time_slice > HALF_JIFFY_US)
+ return;
+ else
+ rq->rq_time_slice = 0;
+ } else if (rq->rq_time_slice >= RESCHED_US)
+ return;
+
+ /* p->time_slice < RESCHED_US. We only modify task_struct under grq lock */
+ p = rq->curr;
+ requeue_task(p);
+ grq_lock();
+ set_tsk_need_resched(p);
+ grq_unlock();
+}
+
+void wake_up_idle_cpu(int cpu);
+
+/*
+ * This function gets called by the timer code, with HZ frequency.
+ * We call it with interrupts disabled. The data modified is all
+ * local to struct rq so we don't need to grab grq lock.
+ */
+void scheduler_tick(void)
+{
+ int cpu = smp_processor_id();
+ struct rq *rq = cpu_rq(cpu);
+
+ sched_clock_tick();
+ /* grq lock not grabbed, so only update rq clock */
+ update_rq_clock(rq);
+ update_cpu_clock(rq, rq->curr, 1);
+ if (!rq_idle(rq))
+ task_running_tick(rq);
+ else
+ no_iso_tick();
+ rq->last_tick = rq->clock;
+ perf_event_task_tick(rq->curr, cpu);
+}
+
+notrace unsigned long get_parent_ip(unsigned long addr)
+{
+ if (in_lock_functions(addr)) {
+ addr = CALLER_ADDR2;
+ if (in_lock_functions(addr))
+ addr = CALLER_ADDR3;
+ }
+ return addr;
+}
+
+#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
+ defined(CONFIG_PREEMPT_TRACER))
+void __kprobes add_preempt_count(int val)
+{
+#ifdef CONFIG_DEBUG_PREEMPT
+ /*
+ * Underflow?
+ */
+ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
+ return;
+#endif
+ preempt_count() += val;
+#ifdef CONFIG_DEBUG_PREEMPT
+ /*
+ * Spinlock count overflowing soon?
+ */
+ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
+ PREEMPT_MASK - 10);
+#endif
+ if (preempt_count() == val)
+ trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+}
+EXPORT_SYMBOL(add_preempt_count);
+
+void __kprobes sub_preempt_count(int val)
+{
+#ifdef CONFIG_DEBUG_PREEMPT
+ /*
+ * Underflow?
+ */
+ if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
+ return;
+ /*
+ * Is the spinlock portion underflowing?
+ */
+ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
+ !(preempt_count() & PREEMPT_MASK)))
+ return;
+#endif
+
+ if (preempt_count() == val)
+ trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ preempt_count() -= val;
+}
+EXPORT_SYMBOL(sub_preempt_count);
+#endif
+
+/*
+ * Deadline is "now" in niffies + (offset by priority). Setting the deadline
+ * is the key to everything. It distributes cpu fairly amongst tasks of the
+ * same nice value, it proportions cpu according to nice level, it means the
+ * task that last woke up the longest ago has the earliest deadline, thus
+ * ensuring that interactive tasks get low latency on wake up. The CPU
+ * proportion works out to the square of the virtual deadline difference, so
+ * this equation will give nice 19 3% CPU compared to nice 0.
+ */
+static inline u64 prio_deadline_diff(int user_prio)
+{
+ return (prio_ratios[user_prio] * rr_interval * (MS_TO_NS(1) / 128));
+}
+
+static inline u64 task_deadline_diff(struct task_struct *p)
+{
+ return prio_deadline_diff(TASK_USER_PRIO(p));
+}
+
+static inline u64 static_deadline_diff(int static_prio)
+{
+ return prio_deadline_diff(USER_PRIO(static_prio));
+}
+
+static inline int ms_longest_deadline_diff(void)
+{
+ return NS_TO_MS(prio_deadline_diff(39));
+}
+
+/*
+ * The time_slice is only refilled when it is empty and that is when we set a
+ * new deadline.
+ */
+static void time_slice_expired(struct task_struct *p)
+{
+ p->time_slice = timeslice();
+ p->deadline = grq.niffies + task_deadline_diff(p);
+}
+
+/*
+ * Timeslices below RESCHED_US are considered as good as expired as there's no
+ * point rescheduling when there's so little time left. SCHED_BATCH tasks
+ * have been flagged be not latency sensitive and likely to be fully CPU
+ * bound so every time they're rescheduled they have their time_slice
+ * refilled, but get a new later deadline to have little effect on
+ * SCHED_NORMAL tasks.
+
+ */
+static inline void check_deadline(struct task_struct *p)
+{
+ if (p->time_slice < RESCHED_US || batch_task(p))
+ time_slice_expired(p);
+}
+
+/*
+ * O(n) lookup of all tasks in the global runqueue. The real brainfuck
+ * of lock contention and O(n). It's not really O(n) as only the queued,
+ * but not running tasks are scanned, and is O(n) queued in the worst case
+ * scenario only because the right task can be found before scanning all of
+ * them.
+ * Tasks are selected in this order:
+ * Real time tasks are selected purely by their static priority and in the
+ * order they were queued, so the lowest value idx, and the first queued task
+ * of that priority value is chosen.
+ * If no real time tasks are found, the SCHED_ISO priority is checked, and
+ * all SCHED_ISO tasks have the same priority value, so they're selected by
+ * the earliest deadline value.
+ * If no SCHED_ISO tasks are found, SCHED_NORMAL tasks are selected by the
+ * earliest deadline.
+ * Finally if no SCHED_NORMAL tasks are found, SCHED_IDLEPRIO tasks are
+ * selected by the earliest deadline.
+ */
+static inline struct
+task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle)
+{
+ u64 dl, earliest_deadline = 0; /* Initialise to silence compiler */
+ struct task_struct *p, *edt = idle;
+ unsigned int cpu = cpu_of(rq);
+ struct list_head *queue;
+ int idx = 0;
+
+retry:
+ idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx);
+ if (idx >= PRIO_LIMIT)
+ goto out;
+ queue = grq.queue + idx;
+ list_for_each_entry(p, queue, run_list) {
+ /* Make sure cpu affinity is ok */
+ if (needs_other_cpu(p, cpu))
+ continue;
+ if (idx < MAX_RT_PRIO) {
+ /* We found an rt task */
+ edt = p;
+ goto out_take;
+ }
+
+ dl = p->deadline + cache_distance(task_rq(p), rq, p);
+
+ /*
+ * No rt tasks. Find the earliest deadline task. Now we're in
+ * O(n) territory. This is what we silenced the compiler for:
+ * edt will always start as idle.
+ */
+ if (edt == idle ||
+ deadline_before(dl, earliest_deadline)) {
+ earliest_deadline = dl;
+ edt = p;
+ }
+ }
+ if (edt == idle) {
+ if (++idx < PRIO_LIMIT)
+ goto retry;
+ goto out;
+ }
+out_take:
+ take_task(rq, edt);
+out:
+ return edt;
+}
+
+/*
+ * Print scheduling while atomic bug:
+ */
+static noinline void __schedule_bug(struct task_struct *prev)
+{
+ struct pt_regs *regs = get_irq_regs();
+
+ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
+ prev->comm, prev->pid, preempt_count());
+
+ debug_show_held_locks(prev);
+ print_modules();
+ if (irqs_disabled())
+ print_irqtrace_events(prev);
+
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
+}
+
+/*
+ * Various schedule()-time debugging checks and statistics:
+ */
+static inline void schedule_debug(struct task_struct *prev)
+{
+ /*
+ * Test if we are atomic. Since do_exit() needs to call into
+ * schedule() atomically, we ignore that path for now.
+ * Otherwise, whine if we are scheduling when we should not be.
+ */
+ if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
+ __schedule_bug(prev);
+
+ profile_hit(SCHED_PROFILING, __builtin_return_address(0));
+
+ schedstat_inc(this_rq(), sched_count);
+#ifdef CONFIG_SCHEDSTATS
+ if (unlikely(prev->lock_depth >= 0)) {
+ schedstat_inc(this_rq(), bkl_count);
+ schedstat_inc(prev, sched_info.bkl_count);
+ }
+#endif
+}
+
+/*
+ * The currently running task's information is all stored in rq local data
+ * which is only modified by the local CPU, thereby allowing the data to be
+ * changed without grabbing the grq lock.
+ */
+static inline void set_rq_task(struct rq *rq, struct task_struct *p)
+{
+ rq->rq_time_slice = p->time_slice;
+ rq->rq_deadline = p->deadline;
+ rq->rq_last_ran = p->last_ran;
+ rq->rq_policy = p->policy;
+ rq->rq_prio = p->prio;
+ if (p != rq->idle)
+ rq->rq_running = 1;
+ else
+ rq->rq_running = 0;
+}
+
+static void reset_rq_task(struct rq *rq, struct task_struct *p)
+{
+ rq->rq_policy = p->policy;
+ rq->rq_prio = p->prio;
+}
+
+/*
+ * schedule() is the main scheduler function.
+ */
+asmlinkage void __sched schedule(void)
+{
+ struct task_struct *prev, *next, *idle;
+ unsigned long *switch_count;
+ int deactivate, cpu;
+ struct rq *rq;
+
+need_resched:
+ preempt_disable();
+
+ cpu = smp_processor_id();
+ rq = cpu_rq(cpu);
+ idle = rq->idle;
+ rcu_sched_qs(cpu);
+ prev = rq->curr;
+ switch_count = &prev->nivcsw;
+
+ release_kernel_lock(prev);
+need_resched_nonpreemptible:
+
+ deactivate = 0;
+ schedule_debug(prev);
+
+ grq_lock_irq();
+ update_clocks(rq);
+ update_cpu_clock(rq, prev, 0);
+ if (rq->clock - rq->last_tick > HALF_JIFFY_NS)
+ rq->dither = 0;
+ else
+ rq->dither = 1;
+
+ clear_tsk_need_resched(prev);
+
+ if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
+ if (unlikely(signal_pending_state(prev->state, prev)))
+ prev->state = TASK_RUNNING;
+ else
+ deactivate = 1;
+ switch_count = &prev->nvcsw;
+ }
+
+ if (prev != idle) {
+ /* Update all the information stored on struct rq */
+ prev->time_slice = rq->rq_time_slice;
+ prev->deadline = rq->rq_deadline;
+ check_deadline(prev);
+ prev->last_ran = rq->clock;
+
+ /* Task changed affinity off this CPU */
+ if (needs_other_cpu(prev, cpu))
+ resched_suitable_idle(prev);
+ else if (!deactivate) {
+ if (!queued_notrunning()) {
+ /*
+ * We now know prev is the only thing that is
+ * awaiting CPU so we can bypass rechecking for
+ * the earliest deadline task and just run it
+ * again.
+ */
+ grq_unlock_irq();
+ goto rerun_prev_unlocked;
+ } else {
+ /*
+ * If prev got kicked off by a task that has to
+ * run on this CPU for affinity reasons then
+ * there may be an idle CPU it can go to.
+ */
+ resched_suitable_idle(prev);
+ }
+ }
+ return_task(prev, deactivate);
+ }
+
+ if (unlikely(!queued_notrunning())) {
+ /*
+ * This CPU is now truly idle as opposed to when idle is
+ * scheduled as a high priority task in its own right.
+ */
+ next = idle;
+ schedstat_inc(rq, sched_goidle);
+ set_cpuidle_map(cpu);
+ } else {
+ next = earliest_deadline_task(rq, idle);
+ prefetch(next);
+ prefetch_stack(next);
+ clear_cpuidle_map(cpu);
+ }
+
+ if (likely(prev != next)) {
+ sched_info_switch(prev, next);
+ perf_event_task_sched_out(prev, next, cpu);
+
+ if (prev != idle)
+ set_last_task(rq, prev);
+ set_rq_task(rq, next);
+ grq.nr_switches++;
+ prev->oncpu = 0;
+ next->oncpu = 1;
+ rq->curr = next;
+ ++*switch_count;
+
+ context_switch(rq, prev, next); /* unlocks the grq */
+ /*
+ * the context switch might have flipped the stack from under
+ * us, hence refresh the local variables.
+ */
+ cpu = smp_processor_id();
+ rq = cpu_rq(cpu);
+ idle = rq->idle;
+ } else
+ grq_unlock_irq();
+
+rerun_prev_unlocked:
+ if (unlikely(reacquire_kernel_lock(current) < 0))
+ goto need_resched_nonpreemptible;
+ preempt_enable_no_resched();
+ if (need_resched())
+ goto need_resched;
+}
+EXPORT_SYMBOL(schedule);
+
+#ifdef CONFIG_SMP
+int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
+{
+ unsigned int cpu;
+ struct rq *rq;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ /*
+ * Need to access the cpu field knowing that
+ * DEBUG_PAGEALLOC could have unmapped it if
+ * the mutex owner just released it and exited.
+ */
+ if (probe_kernel_address(&owner->cpu, cpu))
+ goto out;
+#else
+ cpu = owner->cpu;
+#endif
+
+ /*
+ * Even if the access succeeded (likely case),
+ * the cpu field may no longer be valid.
+ */
+ if (cpu >= nr_cpumask_bits)
+ goto out;
+
+ /*
+ * We need to validate that we can do a
+ * get_cpu() and that we have the percpu area.
+ */
+ if (!cpu_online(cpu))
+ goto out;
+
+ rq = cpu_rq(cpu);
+
+ for (;;) {
+ /*
+ * Owner changed, break to re-assess state.
+ */
+ if (lock->owner != owner)
+ break;
+
+ /*
+ * Is that owner really running on that cpu?
+ */
+ if (task_thread_info(rq->curr) != owner || need_resched())
+ return 0;
+
+ cpu_relax();
+ }
+out:
+ return 1;
+}
+#endif
+
+#ifdef CONFIG_PREEMPT
+/*
+ * this is the entry point to schedule() from in-kernel preemption
+ * off of preempt_enable. Kernel preemptions off return from interrupt
+ * occur there and call schedule directly.
+ */
+asmlinkage void __sched preempt_schedule(void)
+{
+ struct thread_info *ti = current_thread_info();
+
+ /*
+ * If there is a non-zero preempt_count or interrupts are disabled,
+ * we do not want to preempt the current task. Just return..
+ */
+ if (likely(ti->preempt_count || irqs_disabled()))
+ return;
+
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+ schedule();
+ sub_preempt_count(PREEMPT_ACTIVE);
+
+ /*
+ * Check again in case we missed a preemption opportunity
+ * between schedule and now.
+ */
+ barrier();
+ } while (need_resched());
+}
+EXPORT_SYMBOL(preempt_schedule);
+
+/*
+ * this is the entry point to schedule() from kernel preemption
+ * off of irq context.
+ * Note, that this is called and return with irqs disabled. This will
+ * protect us against recursive calling from irq.
+ */
+asmlinkage void __sched preempt_schedule_irq(void)
+{
+ struct thread_info *ti = current_thread_info();
+
+ /* Catch callers which need to be fixed */
+ BUG_ON(ti->preempt_count || !irqs_disabled());
+
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+ local_irq_enable();
+ schedule();
+ local_irq_disable();
+ sub_preempt_count(PREEMPT_ACTIVE);
+
+ /*
+ * Check again in case we missed a preemption opportunity
+ * between schedule and now.
+ */
+ barrier();
+ } while (need_resched());
+}
+
+#endif /* CONFIG_PREEMPT */
+
+int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
+ void *key)
+{
+ return try_to_wake_up(curr->private, mode, wake_flags);
+}
+EXPORT_SYMBOL(default_wake_function);
+
+/*
+ * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
+ * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
+ * number) then we wake all the non-exclusive tasks and one exclusive task.
+ *
+ * There are circumstances in which we can try to wake a task which has already
+ * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
+ * zero in this (rare) case, and we handle it by continuing to scan the queue.
+ */
+static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
+ int nr_exclusive, int wake_flags, void *key)
+{
+ struct list_head *tmp, *next;
+
+ list_for_each_safe(tmp, next, &q->task_list) {
+ wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
+ unsigned int flags = curr->flags;
+
+ if (curr->func(curr, mode, wake_flags, key) &&
+ (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
+ break;
+ }
+}
+
+/**
+ * __wake_up - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: is directly passed to the wakeup function
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up(wait_queue_head_t *q, unsigned int mode,
+ int nr_exclusive, void *key)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __wake_up_common(q, mode, nr_exclusive, 0, key);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(__wake_up);
+
+/*
+ * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
+ */
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
+{
+ __wake_up_common(q, mode, 1, 0, NULL);
+}
+
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
+{
+ __wake_up_common(q, mode, 1, 0, key);
+}
+
+/**
+ * __wake_up_sync_key - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: opaque value to be passed to wakeup targets
+ *
+ * The sync wakeup differs that the waker knows that it will schedule
+ * away soon, so while the target thread will be woken up, it will not
+ * be migrated to another CPU - ie. the two threads are 'synchronised'
+ * with each other. This can prevent needless bouncing between CPUs.
+ *
+ * On UP it can prevent extra preemption.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
+ int nr_exclusive, void *key)
+{
+ unsigned long flags;
+ int wake_flags = WF_SYNC;
+
+ if (unlikely(!q))
+ return;
+
+ if (unlikely(!nr_exclusive))
+ wake_flags = 0;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(__wake_up_sync_key);
+
+/**
+ * __wake_up_sync - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ *
+ * The sync wakeup differs that the waker knows that it will schedule
+ * away soon, so while the target thread will be woken up, it will not
+ * be migrated to another CPU - ie. the two threads are 'synchronised'
+ * with each other. This can prevent needless bouncing between CPUs.
+ *
+ * On UP it can prevent extra preemption.
+ */
+void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
+{
+ unsigned long flags;
+ int sync = 1;
+
+ if (unlikely(!q))
+ return;
+
+ if (unlikely(!nr_exclusive))
+ sync = 0;
+
+ spin_lock_irqsave(&q->lock, flags);
+ __wake_up_common(q, mode, nr_exclusive, sync, NULL);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
+
+/**
+ * complete: - signals a single thread waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. Threads will be
+ * awakened in the same order in which they were queued.
+ *
+ * See also complete_all(), wait_for_completion() and related routines.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete(struct completion *x)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&x->wait.lock, flags);
+ x->done++;
+ __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
+ spin_unlock_irqrestore(&x->wait.lock, flags);
+}
+EXPORT_SYMBOL(complete);
+
+/**
+ * complete_all: - signals all threads waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete_all(struct completion *x)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&x->wait.lock, flags);
+ x->done += UINT_MAX/2;
+ __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
+ spin_unlock_irqrestore(&x->wait.lock, flags);
+}
+EXPORT_SYMBOL(complete_all);
+
+static inline long __sched
+do_wait_for_common(struct completion *x, long timeout, int state)
+{
+ if (!x->done) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ wait.flags |= WQ_FLAG_EXCLUSIVE;
+ __add_wait_queue_tail(&x->wait, &wait);
+ do {
+ if (signal_pending_state(state, current)) {
+ timeout = -ERESTARTSYS;
+ break;
+ }
+ __set_current_state(state);
+ spin_unlock_irq(&x->wait.lock);
+ timeout = schedule_timeout(timeout);
+ spin_lock_irq(&x->wait.lock);
+ } while (!x->done && timeout);
+ __remove_wait_queue(&x->wait, &wait);
+ if (!x->done)
+ return timeout;
+ }
+ x->done--;
+ return timeout ?: 1;
+}
+
+static long __sched
+wait_for_common(struct completion *x, long timeout, int state)
+{
+ might_sleep();
+
+ spin_lock_irq(&x->wait.lock);
+ timeout = do_wait_for_common(x, timeout, state);
+ spin_unlock_irq(&x->wait.lock);
+ return timeout;
+}
+
+/**
+ * wait_for_completion: - waits for completion of a task
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ *
+ * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
+ * and interrupt capability. Also see complete().
+ */
+void __sched wait_for_completion(struct completion *x)
+{
+ wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion);
+
+/**
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ */
+unsigned long __sched
+wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+{
+ return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_timeout);
+
+/**
+ * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * @x: holds the state of this particular completion
+ *
+ * This waits for completion of a specific task to be signaled. It is
+ * interruptible.
+ */
+int __sched wait_for_completion_interruptible(struct completion *x)
+{
+ long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
+ if (t == -ERESTARTSYS)
+ return t;
+ return 0;
+}
+EXPORT_SYMBOL(wait_for_completion_interruptible);
+
+/**
+ * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ */
+unsigned long __sched
+wait_for_completion_interruptible_timeout(struct completion *x,
+ unsigned long timeout)
+{
+ return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+
+/**
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ */
+int __sched wait_for_completion_killable(struct completion *x)
+{
+ long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
+ if (t == -ERESTARTSYS)
+ return t;
+ return 0;
+}
+EXPORT_SYMBOL(wait_for_completion_killable);
+
+/**
+ * try_wait_for_completion - try to decrement a completion without blocking
+ * @x: completion structure
+ *
+ * Returns: 0 if a decrement cannot be done without blocking
+ * 1 if a decrement succeeded.
+ *
+ * If a completion is being used as a counting completion,
+ * attempt to decrement the counter without blocking. This
+ * enables us to avoid waiting if the resource the completion
+ * is protecting is not available.
+ */
+bool try_wait_for_completion(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ else
+ x->done--;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+EXPORT_SYMBOL(try_wait_for_completion);
+
+/**
+ * completion_done - Test to see if a completion has any waiters
+ * @x: completion structure
+ *
+ * Returns: 0 if there are waiters (wait_for_completion() in progress)
+ * 1 if there are no waiters.
+ *
+ */
+bool completion_done(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+EXPORT_SYMBOL(completion_done);
+
+static long __sched
+sleep_on_common(wait_queue_head_t *q, int state, long timeout)
+{
+ unsigned long flags;
+ wait_queue_t wait;
+
+ init_waitqueue_entry(&wait, current);
+
+ __set_current_state(state);
+
+ spin_lock_irqsave(&q->lock, flags);
+ __add_wait_queue(q, &wait);
+ spin_unlock(&q->lock);
+ timeout = schedule_timeout(timeout);
+ spin_lock_irq(&q->lock);
+ __remove_wait_queue(q, &wait);
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return timeout;
+}
+
+void __sched interruptible_sleep_on(wait_queue_head_t *q)
+{
+ sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+}
+EXPORT_SYMBOL(interruptible_sleep_on);
+
+long __sched
+interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
+{
+ return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
+}
+EXPORT_SYMBOL(interruptible_sleep_on_timeout);
+
+void __sched sleep_on(wait_queue_head_t *q)
+{
+ sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+}
+EXPORT_SYMBOL(sleep_on);
+
+long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
+{
+ return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
+}
+EXPORT_SYMBOL(sleep_on_timeout);
+
+#ifdef CONFIG_RT_MUTEXES
+
+/*
+ * rt_mutex_setprio - set the current priority of a task
+ * @p: task
+ * @prio: prio value (kernel-internal form)
+ *
+ * This function changes the 'effective' priority of a task. It does
+ * not touch ->normal_prio like __setscheduler().
+ *
+ * Used by the rt_mutex code to implement priority inheritance logic.
+ */
+void rt_mutex_setprio(struct task_struct *p, int prio)
+{
+ unsigned long flags;
+ int queued, oldprio;
+ struct rq *rq;
+
+ BUG_ON(prio < 0 || prio > MAX_PRIO);
+
+ rq = task_grq_lock(p, &flags);
+
+ oldprio = p->prio;
+ queued = task_queued(p);
+ if (queued)
+ dequeue_task(p);
+ p->prio = prio;
+ if (task_running(p) && prio > oldprio)
+ resched_task(p);
+ if (queued) {
+ enqueue_task(p);
+ try_preempt(p, rq);
+ }
+
+ task_grq_unlock(&flags);
+}
+
+#endif
+
+/*
+ * Adjust the deadline for when the priority is to change, before it's
+ * changed.
+ */
+static inline void adjust_deadline(struct task_struct *p, int new_prio)
+{
+ p->deadline += static_deadline_diff(new_prio) - task_deadline_diff(p);
+}
+
+void set_user_nice(struct task_struct *p, long nice)
+{
+ int queued, new_static, old_static;
+ unsigned long flags;
+ struct rq *rq;
+
+ if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
+ return;
+ new_static = NICE_TO_PRIO(nice);
+ /*
+ * We have to be careful, if called from sys_setpriority(),
+ * the task might be in the middle of scheduling on another CPU.
+ */
+ rq = time_task_grq_lock(p, &flags);
+ /*
+ * The RT priorities are set via sched_setscheduler(), but we still
+ * allow the 'normal' nice value to be set - but as expected
+ * it wont have any effect on scheduling until the task is
+ * not SCHED_NORMAL/SCHED_BATCH:
+ */
+ if (has_rt_policy(p)) {
+ p->static_prio = new_static;
+ goto out_unlock;
+ }
+ queued = task_queued(p);
+ if (queued)
+ dequeue_task(p);
+
+ adjust_deadline(p, new_static);
+ old_static = p->static_prio;
+ p->static_prio = new_static;
+ p->prio = effective_prio(p);
+
+ if (queued) {
+ enqueue_task(p);
+ if (new_static < old_static)
+ try_preempt(p, rq);
+ } else if (task_running(p)) {
+ reset_rq_task(rq, p);
+ if (old_static < new_static)
+ resched_task(p);
+ }
+out_unlock:
+ task_grq_unlock(&flags);
+}
+EXPORT_SYMBOL(set_user_nice);
+
+/*
+ * can_nice - check if a task can reduce its nice value
+ * @p: task
+ * @nice: nice value
+ */
+int can_nice(const struct task_struct *p, const int nice)
+{
+ /* convert nice value [19,-20] to rlimit style value [1,40] */
+ int nice_rlim = 20 - nice;
+
+ return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
+ capable(CAP_SYS_NICE));
+}
+
+#ifdef __ARCH_WANT_SYS_NICE
+
+/*
+ * sys_nice - change the priority of the current process.
+ * @increment: priority increment
+ *
+ * sys_setpriority is a more generic, but much slower function that
+ * does similar things.
+ */
+SYSCALL_DEFINE1(nice, int, increment)
+{
+ long nice, retval;
+
+ /*
+ * Setpriority might change our priority at the same moment.
+ * We don't have to worry. Conceptually one call occurs first
+ * and we have a single winner.
+ */
+ if (increment < -40)
+ increment = -40;
+ if (increment > 40)
+ increment = 40;
+
+ nice = TASK_NICE(current) + increment;
+ if (nice < -20)
+ nice = -20;
+ if (nice > 19)
+ nice = 19;
+
+ if (increment < 0 && !can_nice(current, nice))
+ return -EPERM;
+
+ retval = security_task_setnice(current, nice);
+ if (retval)
+ return retval;
+
+ set_user_nice(current, nice);
+ return 0;
+}
+
+#endif
+
+/**
+ * task_prio - return the priority value of a given task.
+ * @p: the task in question.
+ *
+ * This is the priority value as seen by users in /proc.
+ * RT tasks are offset by -100. Normal tasks are centered around 1, value goes
+ * from 0 (SCHED_ISO) up to 82 (nice +19 SCHED_IDLEPRIO).
+ */
+int task_prio(const struct task_struct *p)
+{
+ int delta, prio = p->prio - MAX_RT_PRIO;
+
+ /* rt tasks and iso tasks */
+ if (prio <= 0)
+ goto out;
+
+ /* Convert to ms to avoid overflows */
+ delta = NS_TO_MS(p->deadline - grq.niffies);
+ delta = delta * 40 / ms_longest_deadline_diff();
+ if (delta > 0 && delta <= 80)
+ prio += delta;
+ if (idleprio_task(p))
+ prio += 40;
+out:
+ return prio;
+}
+
+/**
+ * task_nice - return the nice value of a given task.
+ * @p: the task in question.
+ */
+int task_nice(const struct task_struct *p)
+{
+ return TASK_NICE(p);
+}
+EXPORT_SYMBOL_GPL(task_nice);
+
+/**
+ * idle_cpu - is a given cpu idle currently?
+ * @cpu: the processor in question.
+ */
+int idle_cpu(int cpu)
+{
+ return cpu_curr(cpu) == cpu_rq(cpu)->idle;
+}
+
+/**
+ * idle_task - return the idle task for a given cpu.
+ * @cpu: the processor in question.
+ */
+struct task_struct *idle_task(int cpu)
+{
+ return cpu_rq(cpu)->idle;
+}
+
+/**
+ * find_process_by_pid - find a process with a matching PID value.
+ * @pid: the pid in question.
+ */
+static inline struct task_struct *find_process_by_pid(pid_t pid)
+{
+ return pid ? find_task_by_vpid(pid) : current;
+}
+
+/* Actually do priority change: must hold grq lock. */
+static void
+__setscheduler(struct task_struct *p, struct rq *rq, int policy, int prio)
+{
+ int oldrtprio, oldprio;
+
+ BUG_ON(task_queued(p));
+
+ p->policy = policy;
+ oldrtprio = p->rt_priority;
+ p->rt_priority = prio;
+ p->normal_prio = normal_prio(p);
+ oldprio = p->prio;
+ /* we are holding p->pi_lock already */
+ p->prio = rt_mutex_getprio(p);
+ if (task_running(p)) {
+ reset_rq_task(rq, p);
+ /* Resched only if we might now be preempted */
+ if (p->prio > oldprio || p->rt_priority > oldrtprio)
+ resched_task(p);
+ }
+}
+
+/*
+ * check the target process has a UID that matches the current process's
+ */
+static bool check_same_owner(struct task_struct *p)
+{
+ const struct cred *cred = current_cred(), *pcred;
+ bool match;
+
+ rcu_read_lock();
+ pcred = __task_cred(p);
+ match = (cred->euid == pcred->euid ||
+ cred->euid == pcred->uid);
+ rcu_read_unlock();
+ return match;
+}
+
+static int __sched_setscheduler(struct task_struct *p, int policy,
+ struct sched_param *param, bool user)
+{
+ struct sched_param zero_param = { .sched_priority = 0 };
+ int queued, retval, oldpolicy = -1;
+ unsigned long flags, rlim_rtprio = 0;
+ int reset_on_fork;
+ struct rq *rq;
+
+ /* may grab non-irq protected spin_locks */
+ BUG_ON(in_interrupt());
+
+ if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) {
+ unsigned long lflags;
+
+ if (!lock_task_sighand(p, &lflags))
+ return -ESRCH;
+ rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
+ unlock_task_sighand(p, &lflags);
+ if (rlim_rtprio)
+ goto recheck;
+ /*
+ * If the caller requested an RT policy without having the
+ * necessary rights, we downgrade the policy to SCHED_ISO.
+ * We also set the parameter to zero to pass the checks.
+ */
+ policy = SCHED_ISO;
+ param = &zero_param;
+ }
+recheck:
+ /* double check policy once rq lock held */
+ if (policy < 0) {
+ reset_on_fork = p->sched_reset_on_fork;
+ policy = oldpolicy = p->policy;
+ } else {
+ reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
+ policy &= ~SCHED_RESET_ON_FORK;
+
+ if (!SCHED_RANGE(policy))
+ return -EINVAL;
+ }
+
+ /*
+ * Valid priorities for SCHED_FIFO and SCHED_RR are
+ * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
+ * SCHED_BATCH is 0.
+ */
+ if (param->sched_priority < 0 ||
+ (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
+ (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
+ return -EINVAL;
+ if (is_rt_policy(policy) != (param->sched_priority != 0))
+ return -EINVAL;
+
+ /*
+ * Allow unprivileged RT tasks to decrease priority:
+ */
+ if (user && !capable(CAP_SYS_NICE)) {
+ if (is_rt_policy(policy)) {
+ /* can't set/change the rt policy */
+ if (policy != p->policy && !rlim_rtprio)
+ return -EPERM;
+
+ /* can't increase priority */
+ if (param->sched_priority > p->rt_priority &&
+ param->sched_priority > rlim_rtprio)
+ return -EPERM;
+ } else {
+ switch (p->policy) {
+ /*
+ * Can only downgrade policies but not back to
+ * SCHED_NORMAL
+ */
+ case SCHED_ISO:
+ if (policy == SCHED_ISO)
+ goto out;
+ if (policy == SCHED_NORMAL)
+ return -EPERM;
+ break;
+ case SCHED_BATCH:
+ if (policy == SCHED_BATCH)
+ goto out;
+ if (policy != SCHED_IDLEPRIO)
+ return -EPERM;
+ break;
+ case SCHED_IDLEPRIO:
+ if (policy == SCHED_IDLEPRIO)
+ goto out;
+ return -EPERM;
+ default:
+ break;
+ }
+ }
+
+ /* can't change other user's priorities */
+ if (!check_same_owner(p))
+ return -EPERM;
+
+ /* Normal users shall not reset the sched_reset_on_fork flag */
+ if (p->sched_reset_on_fork && !reset_on_fork)
+ return -EPERM;
+ }
+
+ retval = security_task_setscheduler(p, policy, param);
+ if (retval)
+ return retval;
+ /*
+ * make sure no PI-waiters arrive (or leave) while we are
+ * changing the priority of the task:
+ */
+ spin_lock_irqsave(&p->pi_lock, flags);
+ /*
+ * To be able to change p->policy safely, the apropriate
+ * runqueue lock must be held.
+ */
+ rq = __task_grq_lock(p);
+ /* recheck policy now with rq lock held */
+ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
+ __task_grq_unlock();
+ spin_unlock_irqrestore(&p->pi_lock, flags);
+ policy = oldpolicy = -1;
+ goto recheck;
+ }
+ update_clocks(rq);
+ p->sched_reset_on_fork = reset_on_fork;
+
+ queued = task_queued(p);
+ if (queued)
+ dequeue_task(p);
+ __setscheduler(p, rq, policy, param->sched_priority);
+ if (queued) {
+ enqueue_task(p);
+ try_preempt(p, rq);
+ }
+ __task_grq_unlock();
+ spin_unlock_irqrestore(&p->pi_lock, flags);
+
+ rt_mutex_adjust_pi(p);
+out:
+ return 0;
+}
+
+/**
+ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * NOTE that the task may be already dead.
+ */
+int sched_setscheduler(struct task_struct *p, int policy,
+ struct sched_param *param)
+{
+ return __sched_setscheduler(p, policy, param, true);
+}
+
+EXPORT_SYMBOL_GPL(sched_setscheduler);
+
+/**
+ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * Just like sched_setscheduler, only don't bother checking if the
+ * current context has permission. For example, this is needed in
+ * stop_machine(): we create temporary high priority worker threads,
+ * but our caller might not have that capability.
+ */
+int sched_setscheduler_nocheck(struct task_struct *p, int policy,
+ struct sched_param *param)
+{
+ return __sched_setscheduler(p, policy, param, false);
+}
+
+static int
+do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
+{
+ struct sched_param lparam;
+ struct task_struct *p;
+ int retval;
+
+ if (!param || pid < 0)
+ return -EINVAL;
+ if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
+ return -EFAULT;
+
+ rcu_read_lock();
+ retval = -ESRCH;
+ p = find_process_by_pid(pid);
+ if (p != NULL)
+ retval = sched_setscheduler(p, policy, &lparam);
+ rcu_read_unlock();
+
+ return retval;
+}
+
+/**
+ * sys_sched_setscheduler - set/change the scheduler policy and RT priority
+ * @pid: the pid in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ */
+asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
+ struct sched_param __user *param)
+{
+ /* negative values for policy are not valid */
+ if (policy < 0)
+ return -EINVAL;
+
+ return do_sched_setscheduler(pid, policy, param);
+}
+
+/**
+ * sys_sched_setparam - set/change the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the new RT priority.
+ */
+SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
+{
+ return do_sched_setscheduler(pid, -1, param);
+}
+
+/**
+ * sys_sched_getscheduler - get the policy (scheduling class) of a thread
+ * @pid: the pid in question.
+ */
+SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
+{
+ struct task_struct *p;
+ int retval = -EINVAL;
+
+ if (pid < 0)
+ goto out_nounlock;
+
+ retval = -ESRCH;
+ read_lock(&tasklist_lock);
+ p = find_process_by_pid(pid);
+ if (p) {
+ retval = security_task_getscheduler(p);
+ if (!retval)
+ retval = p->policy;
+ }
+ read_unlock(&tasklist_lock);
+
+out_nounlock:
+ return retval;
+}
+
+/**
+ * sys_sched_getscheduler - get the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the RT priority.
+ */
+SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
+{
+ struct sched_param lp;
+ struct task_struct *p;
+ int retval = -EINVAL;
+
+ if (!param || pid < 0)
+ goto out_nounlock;
+
+ read_lock(&tasklist_lock);
+ p = find_process_by_pid(pid);
+ retval = -ESRCH;
+ if (!p)
+ goto out_unlock;
+
+ retval = security_task_getscheduler(p);
+ if (retval)
+ goto out_unlock;
+
+ lp.sched_priority = p->rt_priority;
+ read_unlock(&tasklist_lock);
+
+ /*
+ * This one might sleep, we cannot do it with a spinlock held ...
+ */
+ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
+
+out_nounlock:
+ return retval;
+
+out_unlock:
+ read_unlock(&tasklist_lock);
+ return retval;
+}
+
+long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
+{
+ cpumask_var_t cpus_allowed, new_mask;
+ struct task_struct *p;
+ int retval;
+
+ get_online_cpus();
+ read_lock(&tasklist_lock);
+
+ p = find_process_by_pid(pid);
+ if (!p) {
+ read_unlock(&tasklist_lock);
+ put_online_cpus();
+ return -ESRCH;
+ }
+
+ /*
+ * It is not safe to call set_cpus_allowed with the
+ * tasklist_lock held. We will bump the task_struct's
+ * usage count and then drop tasklist_lock.
+ */
+ get_task_struct(p);
+ read_unlock(&tasklist_lock);
+
+ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto out_put_task;
+ }
+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto out_free_cpus_allowed;
+ }
+ retval = -EPERM;
+ if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
+ goto out_unlock;
+
+ retval = security_task_setscheduler(p, 0, NULL);
+ if (retval)
+ goto out_unlock;
+
+ cpuset_cpus_allowed(p, cpus_allowed);
+ cpumask_and(new_mask, in_mask, cpus_allowed);
+again:
+ retval = set_cpus_allowed_ptr(p, new_mask);
+
+ if (!retval) {
+ cpuset_cpus_allowed(p, cpus_allowed);
+ if (!cpumask_subset(new_mask, cpus_allowed)) {
+ /*
+ * We must have raced with a concurrent cpuset
+ * update. Just reset the cpus_allowed to the
+ * cpuset's cpus_allowed
+ */
+ cpumask_copy(new_mask, cpus_allowed);
+ goto again;
+ }
+ }
+out_unlock:
+ free_cpumask_var(new_mask);
+out_free_cpus_allowed:
+ free_cpumask_var(cpus_allowed);
+out_put_task:
+ put_task_struct(p);
+ put_online_cpus();
+ return retval;
+}
+
+static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
+ cpumask_t *new_mask)
+{
+ if (len < sizeof(cpumask_t)) {
+ memset(new_mask, 0, sizeof(cpumask_t));
+ } else if (len > sizeof(cpumask_t)) {
+ len = sizeof(cpumask_t);
+ }
+ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
+}
+
+
+/**
+ * sys_sched_setaffinity - set the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to the new cpu mask
+ */
+SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
+ unsigned long __user *, user_mask_ptr)
+{
+ cpumask_var_t new_mask;
+ int retval;
+
+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
+ if (retval == 0)
+ retval = sched_setaffinity(pid, new_mask);
+ free_cpumask_var(new_mask);
+ return retval;
+}
+
+long sched_getaffinity(pid_t pid, cpumask_t *mask)
+{
+ struct task_struct *p;
+ int retval;
+
+ mutex_lock(&sched_hotcpu_mutex);
+ read_lock(&tasklist_lock);
+
+ retval = -ESRCH;
+ p = find_process_by_pid(pid);
+ if (!p)
+ goto out_unlock;
+
+ retval = security_task_getscheduler(p);
+ if (retval)
+ goto out_unlock;
+
+ cpus_and(*mask, p->cpus_allowed, cpu_online_map);
+
+out_unlock:
+ read_unlock(&tasklist_lock);
+ mutex_unlock(&sched_hotcpu_mutex);
+ if (retval)
+ return retval;
+
+ return 0;
+}
+
+/**
+ * sys_sched_getaffinity - get the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to hold the current cpu mask
+ */
+SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
+ unsigned long __user *, user_mask_ptr)
+{
+ int ret;
+ cpumask_var_t mask;
+
+ if (len < cpumask_size())
+ return -EINVAL;
+
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ ret = sched_getaffinity(pid, mask);
+ if (ret == 0) {
+ if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
+ ret = -EFAULT;
+ else
+ ret = cpumask_size();
+ }
+ free_cpumask_var(mask);
+
+ return ret;
+}
+
+/**
+ * sys_sched_yield - yield the current processor to other threads.
+ *
+ * This function yields the current CPU to other tasks. It does this by
+ * scheduling away the current task. If it still has the earliest deadline
+ * it will be scheduled again as the next task.
+ */
+SYSCALL_DEFINE0(sched_yield)
+{
+ struct task_struct *p;
+ struct rq *rq;
+
+ p = current;
+ rq = task_grq_lock_irq(p);
+ schedstat_inc(rq, yld_count);
+ requeue_task(p);
+
+ /*
+ * Since we are going to call schedule() anyway, there's
+ * no need to preempt or enable interrupts:
+ */
+ __release(grq.lock);
+ spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
+ _raw_spin_unlock(&grq.lock);
+ preempt_enable_no_resched();
+
+ schedule();
+
+ return 0;
+}
+
+static inline int should_resched(void)
+{
+ return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
+}
+
+static void __cond_resched(void)
+{
+ /* NOT a real fix but will make voluntary preempt work. 馬鹿な事 */
+ if (unlikely(system_state != SYSTEM_RUNNING))
+ return;
+
+ add_preempt_count(PREEMPT_ACTIVE);
+ schedule();
+ sub_preempt_count(PREEMPT_ACTIVE);
+}
+
+int __sched _cond_resched(void)
+{
+ if (should_resched()) {
+ __cond_resched();
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(_cond_resched);
+
+/*
+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
+ * call schedule, and on return reacquire the lock.
+ *
+ * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
+ * operations here to prevent schedule() from being called twice (once via
+ * spin_unlock(), once by hand).
+ */
+int __cond_resched_lock(spinlock_t *lock)
+{
+ int resched = should_resched();
+ int ret = 0;
+
+ lockdep_assert_held(lock);
+
+ if (spin_needbreak(lock) || resched) {
+ spin_unlock(lock);
+ if (resched)
+ __cond_resched();
+ else
+ cpu_relax();
+ ret = 1;
+ spin_lock(lock);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(__cond_resched_lock);
+
+int __sched __cond_resched_softirq(void)
+{
+ BUG_ON(!in_softirq());
+
+ if (should_resched()) {
+ local_bh_enable();
+ __cond_resched();
+ local_bh_disable();
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(__cond_resched_softirq);
+
+/**
+ * yield - yield the current processor to other threads.
+ *
+ * This is a shortcut for kernel-space yielding - it marks the
+ * thread runnable and calls sys_sched_yield().
+ */
+void __sched yield(void)
+{
+ set_current_state(TASK_RUNNING);
+ sys_sched_yield();
+}
+EXPORT_SYMBOL(yield);
+
+/*
+ * This task is about to go to sleep on IO. Increment rq->nr_iowait so
+ * that process accounting knows that this is a task in IO wait state.
+ *
+ * But don't do that if it is a deliberate, throttling IO wait (this task
+ * has set its backing_dev_info: the queue against which it should throttle)
+ */
+void __sched io_schedule(void)
+{
+ struct rq *rq = raw_rq();
+
+ delayacct_blkio_start();
+ atomic_inc(&rq->nr_iowait);
+ current->in_iowait = 1;
+ schedule();
+ current->in_iowait = 0;
+ atomic_dec(&rq->nr_iowait);
+ delayacct_blkio_end();
+}
+EXPORT_SYMBOL(io_schedule);
+
+long __sched io_schedule_timeout(long timeout)
+{
+ struct rq *rq = raw_rq();
+ long ret;
+
+ delayacct_blkio_start();
+ atomic_inc(&rq->nr_iowait);
+ current->in_iowait = 1;
+ ret = schedule_timeout(timeout);
+ current->in_iowait = 0;
+ atomic_dec(&rq->nr_iowait);
+ delayacct_blkio_end();
+ return ret;
+}
+
+/**
+ * sys_sched_get_priority_max - return maximum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the maximum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
+{
+ int ret = -EINVAL;
+
+ switch (policy) {
+ case SCHED_FIFO:
+ case SCHED_RR:
+ ret = MAX_USER_RT_PRIO-1;
+ break;
+ case SCHED_NORMAL:
+ case SCHED_BATCH:
+ case SCHED_ISO:
+ case SCHED_IDLEPRIO:
+ ret = 0;
+ break;
+ }
+ return ret;
+}
+
+/**
+ * sys_sched_get_priority_min - return minimum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the minimum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
+{
+ int ret = -EINVAL;
+
+ switch (policy) {
+ case SCHED_FIFO:
+ case SCHED_RR:
+ ret = 1;
+ break;
+ case SCHED_NORMAL:
+ case SCHED_BATCH:
+ case SCHED_ISO:
+ case SCHED_IDLEPRIO:
+ ret = 0;
+ break;
+ }
+ return ret;
+}
+
+/**
+ * sys_sched_rr_get_interval - return the default timeslice of a process.
+ * @pid: pid of the process.
+ * @interval: userspace pointer to the timeslice value.
+ *
+ * this syscall writes the default timeslice value of a given process
+ * into the user-space timespec buffer. A value of '0' means infinity.
+ */
+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+ struct timespec __user *, interval)
+{
+ struct task_struct *p;
+ int retval = -EINVAL;
+ struct timespec t;
+
+ if (pid < 0)
+ goto out_nounlock;
+
+ retval = -ESRCH;
+ read_lock(&tasklist_lock);
+ p = find_process_by_pid(pid);
+ if (!p)
+ goto out_unlock;
+
+ retval = security_task_getscheduler(p);
+ if (retval)
+ goto out_unlock;
+
+ t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
+ MS_TO_NS(task_timeslice(p)));
+ read_unlock(&tasklist_lock);
+ retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
+out_nounlock:
+ return retval;
+out_unlock:
+ read_unlock(&tasklist_lock);
+ return retval;
+}
+
+static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
+
+void sched_show_task(struct task_struct *p)
+{
+ unsigned long free = 0;
+ unsigned state;
+
+ state = p->state ? __ffs(p->state) + 1 : 0;
+ printk(KERN_INFO "%-13.13s %c", p->comm,
+ state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
+#if BITS_PER_LONG == 32
+ if (state == TASK_RUNNING)
+ printk(KERN_CONT " running ");
+ else
+ printk(KERN_CONT " %08lx ", thread_saved_pc(p));
+#else
+ if (state == TASK_RUNNING)
+ printk(KERN_CONT " running task ");
+ else
+ printk(KERN_CONT " %016lx ", thread_saved_pc(p));
+#endif
+#ifdef CONFIG_DEBUG_STACK_USAGE
+ free = stack_not_used(p);
+#endif
+ printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
+ task_pid_nr(p), task_pid_nr(p->real_parent),
+ (unsigned long)task_thread_info(p)->flags);
+
+ show_stack(p, NULL);
+}
+
+void show_state_filter(unsigned long state_filter)
+{
+ struct task_struct *g, *p;
+
+#if BITS_PER_LONG == 32
+ printk(KERN_INFO
+ " task PC stack pid father\n");
+#else
+ printk(KERN_INFO
+ " task PC stack pid father\n");
+#endif
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ /*
+ * reset the NMI-timeout, listing all files on a slow
+ * console might take alot of time:
+ */
+ touch_nmi_watchdog();
+ if (!state_filter || (p->state & state_filter))
+ sched_show_task(p);
+ } while_each_thread(g, p);
+
+ touch_all_softlockup_watchdogs();
+
+ read_unlock(&tasklist_lock);
+ /*
+ * Only show locks if all tasks are dumped:
+ */
+ if (state_filter == -1)
+ debug_show_all_locks();
+}
+
+/**
+ * init_idle - set up an idle thread for a given CPU
+ * @idle: task in question
+ * @cpu: cpu the idle task belongs to
+ *
+ * NOTE: this function does not set the idle thread's NEED_RESCHED
+ * flag, to make booting more robust.
+ */
+void init_idle(struct task_struct *idle, int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
+
+ time_grq_lock(rq, &flags);
+ idle->last_ran = rq->clock;
+ idle->state = TASK_RUNNING;
+ /* Setting prio to illegal value shouldn't matter when never queued */
+ idle->prio = PRIO_LIMIT;
+ set_rq_task(rq, idle);
+ idle->cpus_allowed = cpumask_of_cpu(cpu);
+ set_task_cpu(idle, cpu);
+ rq->curr = rq->idle = idle;
+ idle->oncpu = 1;
+ set_cpuidle_map(cpu);
+ grq_unlock_irqrestore(&flags);
+
+ /* Set the preempt count _outside_ the spinlocks! */
+#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
+ task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
+#else
+ task_thread_info(idle)->preempt_count = 0;
+#endif
+ ftrace_graph_init_task(idle);
+}
+
+/*
+ * In a system that switches off the HZ timer nohz_cpu_mask
+ * indicates which cpus entered this state. This is used
+ * in the rcu update to wait only for active cpus. For system
+ * which do not switch off the HZ timer nohz_cpu_mask should
+ * always be CPU_BITS_NONE.
+ */
+cpumask_var_t nohz_cpu_mask;
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_NO_HZ
+static struct {
+ atomic_t load_balancer;
+ cpumask_var_t cpu_mask;
+ cpumask_var_t ilb_grp_nohz_mask;
+} nohz ____cacheline_aligned = {
+ .load_balancer = ATOMIC_INIT(-1),
+};
+
+int get_nohz_load_balancer(void)
+{
+ return atomic_read(&nohz.load_balancer);
+}
+
+/*
+ * This routine will try to nominate the ilb (idle load balancing)
+ * owner among the cpus whose ticks are stopped. ilb owner will do the idle
+ * load balancing on behalf of all those cpus. If all the cpus in the system
+ * go into this tickless mode, then there will be no ilb owner (as there is
+ * no need for one) and all the cpus will sleep till the next wakeup event
+ * arrives...
+ *
+ * For the ilb owner, tick is not stopped. And this tick will be used
+ * for idle load balancing. ilb owner will still be part of
+ * nohz.cpu_mask..
+ *
+ * While stopping the tick, this cpu will become the ilb owner if there
+ * is no other owner. And will be the owner till that cpu becomes busy
+ * or if all cpus in the system stop their ticks at which point
+ * there is no need for ilb owner.
+ *
+ * When the ilb owner becomes busy, it nominates another owner, during the
+ * next busy scheduler_tick()
+ */
+int select_nohz_load_balancer(int stop_tick)
+{
+ int cpu = smp_processor_id();
+
+ if (stop_tick) {
+ cpu_rq(cpu)->in_nohz_recently = 1;
+
+ if (!cpu_active(cpu)) {
+ if (atomic_read(&nohz.load_balancer) != cpu)
+ return 0;
+
+ /*
+ * If we are going offline and still the leader,
+ * give up!
+ */
+ if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
+ BUG();
+
+ return 0;
+ }
+
+ cpumask_set_cpu(cpu, nohz.cpu_mask);
+
+ /* time for ilb owner also to sleep */
+ if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
+ if (atomic_read(&nohz.load_balancer) == cpu)
+ atomic_set(&nohz.load_balancer, -1);
+ return 0;
+ }
+
+ if (atomic_read(&nohz.load_balancer) == -1) {
+ /* make me the ilb owner */
+ if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
+ return 1;
+ } else if (atomic_read(&nohz.load_balancer) == cpu)
+ return 1;
+ } else {
+ if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
+ return 0;
+
+ cpumask_clear_cpu(cpu, nohz.cpu_mask);
+
+ if (atomic_read(&nohz.load_balancer) == cpu)
+ if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
+ BUG();
+ }
+ return 0;
+}
+
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
+ */
+void wake_up_idle_cpu(int cpu)
+{
+ struct task_struct *idle;
+ struct rq *rq;
+
+ if (cpu == smp_processor_id())
+ return;
+
+ rq = cpu_rq(cpu);
+ idle = rq->idle;
+
+ /*
+ * This is safe, as this function is called with the timer
+ * wheel base lock of (cpu) held. When the CPU is on the way
+ * to idle and has not yet set rq->curr to idle then it will
+ * be serialised on the timer wheel base lock and take the new
+ * timer into account automatically.
+ */
+ if (unlikely(rq->curr != idle))
+ return;
+
+ /*
+ * We can set TIF_RESCHED on the idle task of the other CPU
+ * lockless. The worst case is that the other CPU runs the
+ * idle task through an additional NOOP schedule()
+ */
+ set_tsk_need_resched(idle);
+
+ /* NEED_RESCHED must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(idle))
+ smp_send_reschedule(cpu);
+}
+
+#endif /* CONFIG_NO_HZ */
+
+/*
+ * Change a given task's CPU affinity. Migrate the thread to a
+ * proper CPU and schedule it away if the CPU it's executing on
+ * is removed from the allowed bitmask.
+ *
+ * NOTE: the caller must have a valid reference to the task, the
+ * task must not exit() & deallocate itself prematurely. The
+ * call is not atomic; no spinlocks may be held.
+ */
+int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
+{
+ unsigned long flags;
+ int running_wrong = 0;
+ int queued = 0;
+ struct rq *rq;
+ int ret = 0;
+
+ rq = task_grq_lock(p, &flags);
+ if (!cpumask_intersects(new_mask, cpu_online_mask)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
+ !cpumask_equal(&p->cpus_allowed, new_mask))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ queued = task_queued(p);
+
+ cpumask_copy(&p->cpus_allowed, new_mask);
+
+ /* Can the task run on the task's current CPU? If so, we're done */
+ if (cpumask_test_cpu(task_cpu(p), new_mask))
+ goto out;
+
+ if (task_running(p)) {
+ /* Task is running on the wrong cpu now, reschedule it. */
+ if (rq == this_rq()) {
+ set_tsk_need_resched(p);
+ running_wrong = 1;
+ } else
+ resched_task(p);
+ } else
+ set_task_cpu(p, cpumask_any_and(cpu_active_mask, new_mask));
+
+out:
+ if (queued)
+ try_preempt(p, rq);
+ task_grq_unlock(&flags);
+
+ if (running_wrong)
+ _cond_resched();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Reschedule a task if it's on a dead CPU.
+ */
+void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
+{
+ unsigned long flags;
+ struct rq *rq, *dead_rq;
+
+ dead_rq = cpu_rq(dead_cpu);
+ rq = task_grq_lock(p, &flags);
+ if (rq == dead_rq && task_running(p))
+ resched_task(p);
+ task_grq_unlock(&flags);
+
+}
+
+/*
+ * Schedules idle task to be the next runnable task on current CPU.
+ * It does so by boosting its priority to highest possible.
+ * Used by CPU offline code.
+ */
+void sched_idle_next(void)
+{
+ int this_cpu = smp_processor_id();
+ struct rq *rq = cpu_rq(this_cpu);
+ struct task_struct *idle = rq->idle;
+ unsigned long flags;
+
+ /* cpu has to be offline */
+ BUG_ON(cpu_online(this_cpu));
+
+ /*
+ * Strictly not necessary since rest of the CPUs are stopped by now
+ * and interrupts disabled on the current cpu.
+ */
+ grq_lock_irqsave(&flags);
+
+ __setscheduler(idle, rq, SCHED_FIFO, MAX_RT_PRIO - 1);
+
+ activate_idle_task(idle);
+ set_tsk_need_resched(rq->curr);
+
+ grq_unlock_irqrestore(&flags);
+}
+
+/*
+ * Ensures that the idle task is using init_mm right before its cpu goes
+ * offline.
+ */
+void idle_task_exit(void)
+{
+ struct mm_struct *mm = current->active_mm;
+
+ BUG_ON(cpu_online(smp_processor_id()));
+
+ if (mm != &init_mm)
+ switch_mm(mm, &init_mm, current);
+ mmdrop(mm);
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
+
+static struct ctl_table sd_ctl_dir[] = {
+ {
+ .procname = "sched_domain",
+ .mode = 0555,
+ },
+ {0, },
+};
+
+static struct ctl_table sd_ctl_root[] = {
+ {
+ .ctl_name = CTL_KERN,
+ .procname = "kernel",
+ .mode = 0555,
+ .child = sd_ctl_dir,
+ },
+ {0, },
+};
+
+static struct ctl_table *sd_alloc_ctl_entry(int n)
+{
+ struct ctl_table *entry =
+ kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
+
+ return entry;
+}
+
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+ struct ctl_table *entry;
+
+ /*
+ * In the intermediate directories, both the child directory and
+ * procname are dynamically allocated and could fail but the mode
+ * will always be set. In the lowest directory the names are
+ * static strings and all have proc handlers.
+ */
+ for (entry = *tablep; entry->mode; entry++) {
+ if (entry->child)
+ sd_free_ctl_entry(&entry->child);
+ if (entry->proc_handler == NULL)
+ kfree(entry->procname);
+ }
+
+ kfree(*tablep);
+ *tablep = NULL;
+}
+
+static void
+set_table_entry(struct ctl_table *entry,
+ const char *procname, void *data, int maxlen,
+ mode_t mode, proc_handler *proc_handler)
+{
+ entry->procname = procname;
+ entry->data = data;
+ entry->maxlen = maxlen;
+ entry->mode = mode;
+ entry->proc_handler = proc_handler;
+}
+
+static struct ctl_table *
+sd_alloc_ctl_domain_table(struct sched_domain *sd)
+{
+ struct ctl_table *table = sd_alloc_ctl_entry(13);
+
+ if (table == NULL)
+ return NULL;
+
+ set_table_entry(&table[0], "min_interval", &sd->min_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax);
+ set_table_entry(&table[1], "max_interval", &sd->max_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax);
+ set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[9], "cache_nice_tries",
+ &sd->cache_nice_tries,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[10], "flags", &sd->flags,
+ sizeof(int), 0644, proc_dointvec_minmax);
+ set_table_entry(&table[11], "name", sd->name,
+ CORENAME_MAX_SIZE, 0444, proc_dostring);
+ /* &table[12] is terminator */
+
+ return table;
+}
+
+static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
+{
+ struct ctl_table *entry, *table;
+ struct sched_domain *sd;
+ int domain_num = 0, i;
+ char buf[32];
+
+ for_each_domain(cpu, sd)
+ domain_num++;
+ entry = table = sd_alloc_ctl_entry(domain_num + 1);
+ if (table == NULL)
+ return NULL;
+
+ i = 0;
+ for_each_domain(cpu, sd) {
+ snprintf(buf, 32, "domain%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_domain_table(sd);
+ entry++;
+ i++;
+ }
+ return table;
+}
+
+static struct ctl_table_header *sd_sysctl_header;
+static void register_sched_domain_sysctl(void)
+{
+ int i, cpu_num = num_online_cpus();
+ struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
+ char buf[32];
+
+ WARN_ON(sd_ctl_dir[0].child);
+ sd_ctl_dir[0].child = entry;
+
+ if (entry == NULL)
+ return;
+
+ for_each_online_cpu(i) {
+ snprintf(buf, 32, "cpu%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_cpu_table(i);
+ entry++;
+ }
+
+ WARN_ON(sd_sysctl_header);
+ sd_sysctl_header = register_sysctl_table(sd_ctl_root);
+}
+
+/* may be called multiple times per register */
+static void unregister_sched_domain_sysctl(void)
+{
+ if (sd_sysctl_header)
+ unregister_sysctl_table(sd_sysctl_header);
+ sd_sysctl_header = NULL;
+ if (sd_ctl_dir[0].child)
+ sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
+#else
+static void register_sched_domain_sysctl(void)
+{
+}
+static void unregister_sched_domain_sysctl(void)
+{
+}
+#endif
+
+static void set_rq_online(struct rq *rq)
+{
+ if (!rq->online) {
+ cpumask_set_cpu(cpu_of(rq), rq->rd->online);
+ rq->online = 1;
+ }
+}
+
+static void set_rq_offline(struct rq *rq)
+{
+ if (rq->online) {
+ cpumask_clear_cpu(cpu_of(rq), rq->rd->online);
+ rq->online = 0;
+ }
+}
+
+/*
+ * migration_call - callback that gets triggered when a CPU is added.
+ */
+static int __cpuinit
+migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ struct task_struct *idle;
+#endif
+ int cpu = (long)hcpu;
+ unsigned long flags;
+ struct rq *rq = cpu_rq(cpu);
+
+ switch (action) {
+
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ break;
+
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ /* Update our root-domain */
+ grq_lock_irqsave(&flags);
+ if (rq->rd) {
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+
+ set_rq_online(rq);
+ }
+ grq_unlock_irqrestore(&flags);
+ break;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ break;
+
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ idle = rq->idle;
+ /* Idle task back to normal (off runqueue, low prio) */
+ grq_lock_irq();
+ return_task(idle, 1);
+ idle->static_prio = MAX_PRIO;
+ __setscheduler(idle, rq, SCHED_NORMAL, 0);
+ idle->prio = PRIO_LIMIT;
+ set_rq_task(rq, idle);
+ update_clocks(rq);
+ grq_unlock_irq();
+ break;
+
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
+ /* Update our root-domain */
+ grq_lock_irqsave(&flags);
+ if (rq->rd) {
+ BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+ set_rq_offline(rq);
+ }
+ grq_unlock_irqrestore(&flags);
+ break;
+#endif
+ }
+ return NOTIFY_OK;
+}
+
+/*
+ * Register at high priority so that task migration (migrate_all_tasks)
+ * happens before everything else. This has to be lower priority than
+ * the notifier in the perf_counter subsystem, though.
+ */
+static struct notifier_block __cpuinitdata migration_notifier = {
+ .notifier_call = migration_call,
+ .priority = 10
+};
+
+int __init migration_init(void)
+{
+ void *cpu = (void *)(long)smp_processor_id();
+ int err;
+
+ /* Start one for the boot CPU: */
+ err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
+ BUG_ON(err == NOTIFY_BAD);
+ migration_call(&migration_notifier, CPU_ONLINE, cpu);
+ register_cpu_notifier(&migration_notifier);
+
+ return 0;
+}
+early_initcall(migration_init);
+#endif
+
+/*
+ * sched_domains_mutex serialises calls to arch_init_sched_domains,
+ * detach_destroy_domains and partition_sched_domains.
+ */
+static DEFINE_MUTEX(sched_domains_mutex);
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_SCHED_DEBUG
+
+static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
+ struct cpumask *groupmask)
+{
+ struct sched_group *group = sd->groups;
+ char str[256];
+
+ cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
+ cpumask_clear(groupmask);
+
+ printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
+
+ if (!(sd->flags & SD_LOAD_BALANCE)) {
+ printk("does not load-balance\n");
+ if (sd->parent)
+ printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
+ " has parent");
+ return -1;
+ }
+
+ printk(KERN_CONT "span %s level %s\n", str, sd->name);
+
+ if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
+ printk(KERN_ERR "ERROR: domain->span does not contain "
+ "CPU%d\n", cpu);
+ }
+ if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
+ printk(KERN_ERR "ERROR: domain->groups does not contain"
+ " CPU%d\n", cpu);
+ }
+
+ printk(KERN_DEBUG "%*s groups:", level + 1, "");
+ do {
+ if (!group) {
+ printk("\n");
+ printk(KERN_ERR "ERROR: group is NULL\n");
+ break;
+ }
+
+ if (!group->cpu_power) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: domain->cpu_power not "
+ "set\n");
+ break;
+ }
+
+ if (!cpumask_weight(sched_group_cpus(group))) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: empty group\n");
+ break;
+ }
+
+ if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
+ printk(KERN_CONT "\n");
+ printk(KERN_ERR "ERROR: repeated CPUs\n");
+ break;
+ }
+
+ cpumask_or(groupmask, groupmask, sched_group_cpus(group));
+
+ cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
+
+ printk(KERN_CONT " %s", str);
+ if (group->cpu_power != SCHED_LOAD_SCALE) {
+ printk(KERN_CONT " (cpu_power = %d)",
+ group->cpu_power);
+ }
+
+ group = group->next;
+ } while (group != sd->groups);
+ printk(KERN_CONT "\n");
+
+ if (!cpumask_equal(sched_domain_span(sd), groupmask))
+ printk(KERN_ERR "ERROR: groups don't span domain->span\n");
+
+ if (sd->parent &&
+ !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
+ printk(KERN_ERR "ERROR: parent span is not a superset "
+ "of domain->span\n");
+ return 0;
+}
+
+static void sched_domain_debug(struct sched_domain *sd, int cpu)
+{
+ cpumask_var_t groupmask;
+ int level = 0;
+
+ if (!sd) {
+ printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
+ return;
+ }
+
+ printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+
+ if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
+ printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
+ return;
+ }
+
+ for (;;) {
+ if (sched_domain_debug_one(sd, cpu, level, groupmask))
+ break;
+ level++;
+ sd = sd->parent;
+ if (!sd)
+ break;
+ }
+ free_cpumask_var(groupmask);
+}
+#else /* !CONFIG_SCHED_DEBUG */
+# define sched_domain_debug(sd, cpu) do { } while (0)
+#endif /* CONFIG_SCHED_DEBUG */
+
+static int sd_degenerate(struct sched_domain *sd)
+{
+ if (cpumask_weight(sched_domain_span(sd)) == 1)
+ return 1;
+
+ /* Following flags need at least 2 groups */
+ if (sd->flags & (SD_LOAD_BALANCE |
+ SD_BALANCE_NEWIDLE |
+ SD_BALANCE_FORK |
+ SD_BALANCE_EXEC |
+ SD_SHARE_CPUPOWER |
+ SD_SHARE_PKG_RESOURCES)) {
+ if (sd->groups != sd->groups->next)
+ return 0;
+ }
+
+ /* Following flags don't use groups */
+ if (sd->flags & (SD_WAKE_AFFINE))
+ return 0;
+
+ return 1;
+}
+
+static int
+sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
+{
+ unsigned long cflags = sd->flags, pflags = parent->flags;
+
+ if (sd_degenerate(parent))
+ return 1;
+
+ if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
+ return 0;
+
+ /* Flags needing groups don't count if only 1 group in parent */
+ if (parent->groups == parent->groups->next) {
+ pflags &= ~(SD_LOAD_BALANCE |
+ SD_BALANCE_NEWIDLE |
+ SD_BALANCE_FORK |
+ SD_BALANCE_EXEC |
+ SD_SHARE_CPUPOWER |
+ SD_SHARE_PKG_RESOURCES);
+ if (nr_node_ids == 1)
+ pflags &= ~SD_SERIALIZE;
+ }
+ if (~cflags & pflags)
+ return 0;
+
+ return 1;
+}
+
+static void free_rootdomain(struct root_domain *rd)
+{
+ free_cpumask_var(rd->rto_mask);
+ free_cpumask_var(rd->online);
+ free_cpumask_var(rd->span);
+ kfree(rd);
+}
+
+static void rq_attach_root(struct rq *rq, struct root_domain *rd)
+{
+ struct root_domain *old_rd = NULL;
+ unsigned long flags;
+
+ grq_lock_irqsave(&flags);
+
+ if (rq->rd) {
+ old_rd = rq->rd;
+
+ if (cpumask_test_cpu(cpu_of(rq), old_rd->online))
+ set_rq_offline(rq);
+
+ cpumask_clear_cpu(cpu_of(rq), old_rd->span);
+
+ /*
+ * If we dont want to free the old_rt yet then
+ * set old_rd to NULL to skip the freeing later
+ * in this function:
+ */
+ if (!atomic_dec_and_test(&old_rd->refcount))
+ old_rd = NULL;
+ }
+
+ atomic_inc(&rd->refcount);
+ rq->rd = rd;
+
+ cpumask_set_cpu(cpu_of(rq), rd->span);
+ if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
+ set_rq_online(rq);
+
+ grq_unlock_irqrestore(&flags);
+
+ if (old_rd)
+ free_rootdomain(old_rd);
+}
+
+static int init_rootdomain(struct root_domain *rd, bool bootmem)
+{
+ gfp_t gfp = GFP_KERNEL;
+
+ memset(rd, 0, sizeof(*rd));
+
+ if (bootmem)
+ gfp = GFP_NOWAIT;
+
+ if (!alloc_cpumask_var(&rd->span, gfp))
+ goto out;
+ if (!alloc_cpumask_var(&rd->online, gfp))
+ goto free_span;
+ if (!alloc_cpumask_var(&rd->rto_mask, gfp))
+ goto free_online;
+
+ return 0;
+
+free_online:
+ free_cpumask_var(rd->online);
+free_span:
+ free_cpumask_var(rd->span);
+out:
+ return -ENOMEM;
+}
+
+static void init_defrootdomain(void)
+{
+ init_rootdomain(&def_root_domain, true);
+
+ atomic_set(&def_root_domain.refcount, 1);
+}
+
+static struct root_domain *alloc_rootdomain(void)
+{
+ struct root_domain *rd;
+
+ rd = kmalloc(sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return NULL;
+
+ if (init_rootdomain(rd, false) != 0) {
+ kfree(rd);
+ return NULL;
+ }
+
+ return rd;
+}
+
+/*
+ * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
+ * hold the hotplug lock.
+ */
+static void
+cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ struct sched_domain *tmp;
+
+ /* Remove the sched domains which do not contribute to scheduling. */
+ for (tmp = sd; tmp; ) {
+ struct sched_domain *parent = tmp->parent;
+ if (!parent)
+ break;
+
+ if (sd_parent_degenerate(tmp, parent)) {
+ tmp->parent = parent->parent;
+ if (parent->parent)
+ parent->parent->child = tmp;
+ } else
+ tmp = tmp->parent;
+ }
+
+ if (sd && sd_degenerate(sd)) {
+ sd = sd->parent;
+ if (sd)
+ sd->child = NULL;
+ }
+
+ sched_domain_debug(sd, cpu);
+
+ rq_attach_root(rq, rd);
+ rcu_assign_pointer(rq->sd, sd);
+}
+
+/* cpus with isolated domains */
+static cpumask_var_t cpu_isolated_map;
+
+/* Setup the mask of cpus configured for isolated domains */
+static int __init isolated_cpu_setup(char *str)
+{
+ cpulist_parse(str, cpu_isolated_map);
+ return 1;
+}
+
+__setup("isolcpus=", isolated_cpu_setup);
+
+/*
+ * init_sched_build_groups takes the cpumask we wish to span, and a pointer
+ * to a function which identifies what group(along with sched group) a CPU
+ * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
+ * (due to the fact that we keep track of groups covered with a struct cpumask).
+ *
+ * init_sched_build_groups will build a circular linked list of the groups
+ * covered by the given span, and will set each group's ->cpumask correctly,
+ * and ->cpu_power to 0.
+ */
+static void
+init_sched_build_groups(const struct cpumask *span,
+ const struct cpumask *cpu_map,
+ int (*group_fn)(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg,
+ struct cpumask *tmpmask),
+ struct cpumask *covered, struct cpumask *tmpmask)
+{
+ struct sched_group *first = NULL, *last = NULL;
+ int i;
+
+ cpumask_clear(covered);
+
+ for_each_cpu(i, span) {
+ struct sched_group *sg;
+ int group = group_fn(i, cpu_map, &sg, tmpmask);
+ int j;
+
+ if (cpumask_test_cpu(i, covered))
+ continue;
+
+ cpumask_clear(sched_group_cpus(sg));
+ sg->cpu_power = 0;
+
+ for_each_cpu(j, span) {
+ if (group_fn(j, cpu_map, NULL, tmpmask) != group)
+ continue;
+
+ cpumask_set_cpu(j, covered);
+ cpumask_set_cpu(j, sched_group_cpus(sg));
+ }
+ if (!first)
+ first = sg;
+ if (last)
+ last->next = sg;
+ last = sg;
+ }
+ last->next = first;
+}
+
+#define SD_NODES_PER_DOMAIN 16
+
+#ifdef CONFIG_NUMA
+
+/**
+ * find_next_best_node - find the next node to include in a sched_domain
+ * @node: node whose sched_domain we're building
+ * @used_nodes: nodes already in the sched_domain
+ *
+ * Find the next node to include in a given scheduling domain. Simply
+ * finds the closest node not already in the @used_nodes map.
+ *
+ * Should use nodemask_t.
+ */
+static int find_next_best_node(int node, nodemask_t *used_nodes)
+{
+ int i, n, val, min_val, best_node = 0;
+
+ min_val = INT_MAX;
+
+ for (i = 0; i < nr_node_ids; i++) {
+ /* Start at @node */
+ n = (node + i) % nr_node_ids;
+
+ if (!nr_cpus_node(n))
+ continue;
+
+ /* Skip already used nodes */
+ if (node_isset(n, *used_nodes))
+ continue;
+
+ /* Simple min distance search */
+ val = node_distance(node, n);
+
+ if (val < min_val) {
+ min_val = val;
+ best_node = n;
+ }
+ }
+
+ node_set(best_node, *used_nodes);
+ return best_node;
+}
+
+/**
+ * sched_domain_node_span - get a cpumask for a node's sched_domain
+ * @node: node whose cpumask we're constructing
+ * @span: resulting cpumask
+ *
+ * Given a node, construct a good cpumask for its sched_domain to span. It
+ * should be one that prevents unnecessary balancing, but also spreads tasks
+ * out optimally.
+ */
+static void sched_domain_node_span(int node, struct cpumask *span)
+{
+ nodemask_t used_nodes;
+ int i;
+
+ cpumask_clear(span);
+ nodes_clear(used_nodes);
+
+ cpumask_or(span, span, cpumask_of_node(node));
+ node_set(node, used_nodes);
+
+ for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
+ int next_node = find_next_best_node(node, &used_nodes);
+
+ cpumask_or(span, span, cpumask_of_node(next_node));
+ }
+}
+#endif /* CONFIG_NUMA */
+
+int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
+
+/*
+ * The cpus mask in sched_group and sched_domain hangs off the end.
+ *
+ * ( See the the comments in include/linux/sched.h:struct sched_group
+ * and struct sched_domain. )
+ */
+struct static_sched_group {
+ struct sched_group sg;
+ DECLARE_BITMAP(cpus, CONFIG_NR_CPUS);
+};
+
+struct static_sched_domain {
+ struct sched_domain sd;
+ DECLARE_BITMAP(span, CONFIG_NR_CPUS);
+};
+
+struct s_data {
+#ifdef CONFIG_NUMA
+ int sd_allnodes;
+ cpumask_var_t domainspan;
+ cpumask_var_t covered;
+ cpumask_var_t notcovered;
+#endif
+ cpumask_var_t nodemask;
+ cpumask_var_t this_sibling_map;
+ cpumask_var_t this_core_map;
+ cpumask_var_t send_covered;
+ cpumask_var_t tmpmask;
+ struct sched_group **sched_group_nodes;
+ struct root_domain *rd;
+};
+
+enum s_alloc {
+ sa_sched_groups = 0,
+ sa_rootdomain,
+ sa_tmpmask,
+ sa_send_covered,
+ sa_this_core_map,
+ sa_this_sibling_map,
+ sa_nodemask,
+ sa_sched_group_nodes,
+#ifdef CONFIG_NUMA
+ sa_notcovered,
+ sa_covered,
+ sa_domainspan,
+#endif
+ sa_none,
+};
+
+/*
+ * SMT sched-domains:
+ */
+#ifdef CONFIG_SCHED_SMT
+static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
+static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
+
+static int
+cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg, struct cpumask *unused)
+{
+ if (sg)
+ *sg = &per_cpu(sched_group_cpus, cpu).sg;
+ return cpu;
+}
+#endif /* CONFIG_SCHED_SMT */
+
+/*
+ * multi-core sched-domains:
+ */
+#ifdef CONFIG_SCHED_MC
+static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
+static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
+#endif /* CONFIG_SCHED_MC */
+
+#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
+static int
+cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg, struct cpumask *mask)
+{
+ int group;
+
+ cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
+ group = cpumask_first(mask);
+ if (sg)
+ *sg = &per_cpu(sched_group_core, group).sg;
+ return group;
+}
+#elif defined(CONFIG_SCHED_MC)
+static int
+cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg, struct cpumask *unused)
+{
+ if (sg)
+ *sg = &per_cpu(sched_group_core, cpu).sg;
+ return cpu;
+}
+#endif
+
+static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
+static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
+
+static int
+cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg, struct cpumask *mask)
+{
+ int group;
+#ifdef CONFIG_SCHED_MC
+ cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
+ group = cpumask_first(mask);
+#elif defined(CONFIG_SCHED_SMT)
+ cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
+ group = cpumask_first(mask);
+#else
+ group = cpu;
+#endif
+ if (sg)
+ *sg = &per_cpu(sched_group_phys, group).sg;
+ return group;
+}
+
+/**
+ * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
+ * @group: The group whose first cpu is to be returned.
+ */
+static inline unsigned int group_first_cpu(struct sched_group *group)
+{
+ return cpumask_first(sched_group_cpus(group));
+}
+
+#ifdef CONFIG_NUMA
+/*
+ * The init_sched_build_groups can't handle what we want to do with node
+ * groups, so roll our own. Now each node has its own list of groups which
+ * gets dynamically allocated.
+ */
+static DEFINE_PER_CPU(struct static_sched_domain, node_domains);
+static struct sched_group ***sched_group_nodes_bycpu;
+
+static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains);
+static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes);
+
+static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg,
+ struct cpumask *nodemask)
+{
+ int group;
+
+ cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);
+ group = cpumask_first(nodemask);
+
+ if (sg)
+ *sg = &per_cpu(sched_group_allnodes, group).sg;
+ return group;
+}
+
+static void init_numa_sched_groups_power(struct sched_group *group_head)
+{
+ struct sched_group *sg = group_head;
+ int j;
+
+ if (!sg)
+ return;
+ do {
+ for_each_cpu(j, sched_group_cpus(sg)) {
+ struct sched_domain *sd;
+
+ sd = &per_cpu(phys_domains, j).sd;
+ if (j != group_first_cpu(sd->groups)) {
+ /*
+ * Only add "power" once for each
+ * physical package.
+ */
+ continue;
+ }
+
+ sg->cpu_power += sd->groups->cpu_power;
+ }
+ sg = sg->next;
+ } while (sg != group_head);
+}
+
+static int build_numa_sched_groups(struct s_data *d,
+ const struct cpumask *cpu_map, int num)
+{
+ struct sched_domain *sd;
+ struct sched_group *sg, *prev;
+ int n, j;
+
+ cpumask_clear(d->covered);
+ cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map);
+ if (cpumask_empty(d->nodemask)) {
+ d->sched_group_nodes[num] = NULL;
+ goto out;
+ }
+
+ sched_domain_node_span(num, d->domainspan);
+ cpumask_and(d->domainspan, d->domainspan, cpu_map);
+
+ sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, num);
+ if (!sg) {
+ printk(KERN_WARNING "Can not alloc domain group for node %d\n",
+ num);
+ return -ENOMEM;
+ }
+ d->sched_group_nodes[num] = sg;
+
+ for_each_cpu(j, d->nodemask) {
+ sd = &per_cpu(node_domains, j).sd;
+ sd->groups = sg;
+ }
+
+ sg->cpu_power = 0;
+ cpumask_copy(sched_group_cpus(sg), d->nodemask);
+ sg->next = sg;
+ cpumask_or(d->covered, d->covered, d->nodemask);
+
+ prev = sg;
+ for (j = 0; j < nr_node_ids; j++) {
+ n = (num + j) % nr_node_ids;
+ cpumask_complement(d->notcovered, d->covered);
+ cpumask_and(d->tmpmask, d->notcovered, cpu_map);
+ cpumask_and(d->tmpmask, d->tmpmask, d->domainspan);
+ if (cpumask_empty(d->tmpmask))
+ break;
+ cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n));
+ if (cpumask_empty(d->tmpmask))
+ continue;
+ sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, num);
+ if (!sg) {
+ printk(KERN_WARNING
+ "Can not alloc domain group for node %d\n", j);
+ return -ENOMEM;
+ }
+ sg->cpu_power = 0;
+ cpumask_copy(sched_group_cpus(sg), d->tmpmask);
+ sg->next = prev->next;
+ cpumask_or(d->covered, d->covered, d->tmpmask);
+ prev->next = sg;
+ prev = sg;
+ }
+out:
+ return 0;
+}
+#endif /* CONFIG_NUMA */
+
+#ifdef CONFIG_NUMA
+/* Free memory allocated for various sched_group structures */
+static void free_sched_groups(const struct cpumask *cpu_map,
+ struct cpumask *nodemask)
+{
+ int cpu, i;
+
+ for_each_cpu(cpu, cpu_map) {
+ struct sched_group **sched_group_nodes
+ = sched_group_nodes_bycpu[cpu];
+
+ if (!sched_group_nodes)
+ continue;
+
+ for (i = 0; i < nr_node_ids; i++) {
+ struct sched_group *oldsg, *sg = sched_group_nodes[i];
+
+ cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
+ if (cpumask_empty(nodemask))
+ continue;
+
+ if (sg == NULL)
+ continue;
+ sg = sg->next;
+next_sg:
+ oldsg = sg;
+ sg = sg->next;
+ kfree(oldsg);
+ if (oldsg != sched_group_nodes[i])
+ goto next_sg;
+ }
+ kfree(sched_group_nodes);
+ sched_group_nodes_bycpu[cpu] = NULL;
+ }
+}
+#else /* !CONFIG_NUMA */
+static void free_sched_groups(const struct cpumask *cpu_map,
+ struct cpumask *nodemask)
+{
+}
+#endif /* CONFIG_NUMA */
+
+/*
+ * Initialise sched groups cpu_power.
+ *
+ * cpu_power indicates the capacity of sched group, which is used while
+ * distributing the load between different sched groups in a sched domain.
+ * Typically cpu_power for all the groups in a sched domain will be same unless
+ * there are asymmetries in the topology. If there are asymmetries, group
+ * having more cpu_power will pickup more load compared to the group having
+ * less cpu_power.
+ *
+ * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
+ * the maximum number of tasks a group can handle in the presence of other idle
+ * or lightly loaded groups in the same sched domain.
+ */
+static void init_sched_groups_power(int cpu, struct sched_domain *sd)
+{
+ struct sched_domain *child;
+ struct sched_group *group;
+ long power;
+ int weight;
+
+ WARN_ON(!sd || !sd->groups);
+
+ if (cpu != group_first_cpu(sd->groups))
+ return;
+
+ child = sd->child;
+
+ sd->groups->cpu_power = 0;
+
+ if (!child) {
+ power = SCHED_LOAD_SCALE;
+ weight = cpumask_weight(sched_domain_span(sd));
+ /*
+ * SMT siblings share the power of a single core.
+ * Usually multiple threads get a better yield out of
+ * that one core than a single thread would have,
+ * reflect that in sd->smt_gain.
+ */
+ if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
+ power *= sd->smt_gain;
+ power /= weight;
+ power >>= SCHED_LOAD_SHIFT;
+ }
+ sd->groups->cpu_power += power;
+ return;
+ }
+
+ /*
+ * Add cpu_power of each child group to this groups cpu_power
+ */
+ group = child->groups;
+ do {
+ sd->groups->cpu_power += group->cpu_power;
+ group = group->next;
+ } while (group != child->groups);
+}
+
+/*
+ * Initialisers for schedule domains
+ * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
+ */
+
+#ifdef CONFIG_SCHED_DEBUG
+# define SD_INIT_NAME(sd, type) sd->name = #type
+#else
+# define SD_INIT_NAME(sd, type) do { } while (0)
+#endif
+
+#define SD_INIT(sd, type) sd_init_##type(sd)
+
+#define SD_INIT_FUNC(type) \
+static noinline void sd_init_##type(struct sched_domain *sd) \
+{ \
+ memset(sd, 0, sizeof(*sd)); \
+ *sd = SD_##type##_INIT; \
+ sd->level = SD_LV_##type; \
+ SD_INIT_NAME(sd, type); \
+}
+
+SD_INIT_FUNC(CPU)
+#ifdef CONFIG_NUMA
+ SD_INIT_FUNC(ALLNODES)
+ SD_INIT_FUNC(NODE)
+#endif
+#ifdef CONFIG_SCHED_SMT
+ SD_INIT_FUNC(SIBLING)
+#endif
+#ifdef CONFIG_SCHED_MC
+ SD_INIT_FUNC(MC)
+#endif
+
+static int default_relax_domain_level = -1;
+
+static int __init setup_relax_domain_level(char *str)
+{
+ unsigned long val;
+
+ val = simple_strtoul(str, NULL, 0);
+ if (val < SD_LV_MAX)
+ default_relax_domain_level = val;
+
+ return 1;
+}
+__setup("relax_domain_level=", setup_relax_domain_level);
+
+static void set_domain_attribute(struct sched_domain *sd,
+ struct sched_domain_attr *attr)
+{
+ int request;
+
+ if (!attr || attr->relax_domain_level < 0) {
+ if (default_relax_domain_level < 0)
+ return;
+ else
+ request = default_relax_domain_level;
+ } else
+ request = attr->relax_domain_level;
+ if (request < sd->level) {
+ /* turn off idle balance on this domain */
+ sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
+ } else {
+ /* turn on idle balance on this domain */
+ sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
+ }
+}
+
+static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
+ const struct cpumask *cpu_map)
+{
+ switch (what) {
+ case sa_sched_groups:
+ free_sched_groups(cpu_map, d->tmpmask); /* fall through */
+ d->sched_group_nodes = NULL;
+ case sa_rootdomain:
+ free_rootdomain(d->rd); /* fall through */
+ case sa_tmpmask:
+ free_cpumask_var(d->tmpmask); /* fall through */
+ case sa_send_covered:
+ free_cpumask_var(d->send_covered); /* fall through */
+ case sa_this_core_map:
+ free_cpumask_var(d->this_core_map); /* fall through */
+ case sa_this_sibling_map:
+ free_cpumask_var(d->this_sibling_map); /* fall through */
+ case sa_nodemask:
+ free_cpumask_var(d->nodemask); /* fall through */
+ case sa_sched_group_nodes:
+#ifdef CONFIG_NUMA
+ kfree(d->sched_group_nodes); /* fall through */
+ case sa_notcovered:
+ free_cpumask_var(d->notcovered); /* fall through */
+ case sa_covered:
+ free_cpumask_var(d->covered); /* fall through */
+ case sa_domainspan:
+ free_cpumask_var(d->domainspan); /* fall through */
+#endif
+ case sa_none:
+ break;
+ }
+}
+
+static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
+ const struct cpumask *cpu_map)
+{
+#ifdef CONFIG_NUMA
+ if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL))
+ return sa_none;
+ if (!alloc_cpumask_var(&d->covered, GFP_KERNEL))
+ return sa_domainspan;
+ if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL))
+ return sa_covered;
+ /* Allocate the per-node list of sched groups */
+ d->sched_group_nodes = kcalloc(nr_node_ids,
+ sizeof(struct sched_group *), GFP_KERNEL);
+ if (!d->sched_group_nodes) {
+ printk(KERN_WARNING "Can not alloc sched group node list\n");
+ return sa_notcovered;
+ }
+ sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes;
+#endif
+ if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL))
+ return sa_sched_group_nodes;
+ if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL))
+ return sa_nodemask;
+ if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL))
+ return sa_this_sibling_map;
+ if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL))
+ return sa_this_core_map;
+ if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL))
+ return sa_send_covered;
+ d->rd = alloc_rootdomain();
+ if (!d->rd) {
+ printk(KERN_WARNING "Cannot alloc root domain\n");
+ return sa_tmpmask;
+ }
+ return sa_rootdomain;
+}
+
+static struct sched_domain *__build_numa_sched_domains(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i)
+{
+ struct sched_domain *sd = NULL;
+#ifdef CONFIG_NUMA
+ struct sched_domain *parent;
+
+ d->sd_allnodes = 0;
+ if (cpumask_weight(cpu_map) >
+ SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) {
+ sd = &per_cpu(allnodes_domains, i).sd;
+ SD_INIT(sd, ALLNODES);
+ set_domain_attribute(sd, attr);
+ cpumask_copy(sched_domain_span(sd), cpu_map);
+ cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask);
+ d->sd_allnodes = 1;
+ }
+ parent = sd;
+
+ sd = &per_cpu(node_domains, i).sd;
+ SD_INIT(sd, NODE);
+ set_domain_attribute(sd, attr);
+ sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
+ sd->parent = parent;
+ if (parent)
+ parent->child = sd;
+ cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map);
+#endif
+ return sd;
+}
+
+static struct sched_domain *__build_cpu_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd;
+ sd = &per_cpu(phys_domains, i).sd;
+ SD_INIT(sd, CPU);
+ set_domain_attribute(sd, attr);
+ cpumask_copy(sched_domain_span(sd), d->nodemask);
+ sd->parent = parent;
+ if (parent)
+ parent->child = sd;
+ cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask);
+ return sd;
+}
+
+static struct sched_domain *__build_mc_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd = parent;
+#ifdef CONFIG_SCHED_MC
+ sd = &per_cpu(core_domains, i).sd;
+ SD_INIT(sd, MC);
+ set_domain_attribute(sd, attr);
+ cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i));
+ sd->parent = parent;
+ parent->child = sd;
+ cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask);
+#endif
+ return sd;
+}
+
+static struct sched_domain *__build_smt_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd = parent;
+#ifdef CONFIG_SCHED_SMT
+ sd = &per_cpu(cpu_domains, i).sd;
+ SD_INIT(sd, SIBLING);
+ set_domain_attribute(sd, attr);
+ cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i));
+ sd->parent = parent;
+ parent->child = sd;
+ cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask);
+#endif
+ return sd;
+}
+
+static void build_sched_groups(struct s_data *d, enum sched_domain_level l,
+ const struct cpumask *cpu_map, int cpu)
+{
+ switch (l) {
+#ifdef CONFIG_SCHED_SMT
+ case SD_LV_SIBLING: /* set up CPU (sibling) groups */
+ cpumask_and(d->this_sibling_map, cpu_map,
+ topology_thread_cpumask(cpu));
+ if (cpu == cpumask_first(d->this_sibling_map))
+ init_sched_build_groups(d->this_sibling_map, cpu_map,
+ &cpu_to_cpu_group,
+ d->send_covered, d->tmpmask);
+ break;
+#endif
+#ifdef CONFIG_SCHED_MC
+ case SD_LV_MC: /* set up multi-core groups */
+ cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu));
+ if (cpu == cpumask_first(d->this_core_map))
+ init_sched_build_groups(d->this_core_map, cpu_map,
+ &cpu_to_core_group,
+ d->send_covered, d->tmpmask);
+ break;
+#endif
+ case SD_LV_CPU: /* set up physical groups */
+ cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map);
+ if (!cpumask_empty(d->nodemask))
+ init_sched_build_groups(d->nodemask, cpu_map,
+ &cpu_to_phys_group,
+ d->send_covered, d->tmpmask);
+ break;
+#ifdef CONFIG_NUMA
+ case SD_LV_ALLNODES:
+ init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group,
+ d->send_covered, d->tmpmask);
+ break;
+#endif
+ default:
+ break;
+ }
+}
+
+/*
+ * Build sched domains for a given set of cpus and attach the sched domains
+ * to the individual cpus
+ */
+static int __build_sched_domains(const struct cpumask *cpu_map,
+ struct sched_domain_attr *attr)
+{
+ enum s_alloc alloc_state = sa_none;
+ struct s_data d;
+ struct sched_domain *sd;
+ int i;
+#ifdef CONFIG_NUMA
+ d.sd_allnodes = 0;
+#endif
+
+ alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
+ if (alloc_state != sa_rootdomain)
+ goto error;
+ alloc_state = sa_sched_groups;
+
+ /*
+ * Set up domains for cpus specified by the cpu_map.
+ */
+ for_each_cpu(i, cpu_map) {
+ cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)),
+ cpu_map);
+
+ sd = __build_numa_sched_domains(&d, cpu_map, attr, i);
+ sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i);
+ sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i);
+ sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i);
+ }
+
+ for_each_cpu(i, cpu_map) {
+ build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i);
+ build_sched_groups(&d, SD_LV_MC, cpu_map, i);
+ }
+
+ /* Set up physical groups */
+ for (i = 0; i < nr_node_ids; i++)
+ build_sched_groups(&d, SD_LV_CPU, cpu_map, i);
+
+#ifdef CONFIG_NUMA
+ /* Set up node groups */
+ if (d.sd_allnodes)
+ build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0);
+
+ for (i = 0; i < nr_node_ids; i++)
+ if (build_numa_sched_groups(&d, cpu_map, i))
+ goto error;
+#endif
+
+ /* Calculate CPU power for physical packages and nodes */
+#ifdef CONFIG_SCHED_SMT
+ for_each_cpu(i, cpu_map) {
+ sd = &per_cpu(cpu_domains, i).sd;
+ init_sched_groups_power(i, sd);
+ }
+#endif
+#ifdef CONFIG_SCHED_MC
+ for_each_cpu(i, cpu_map) {
+ sd = &per_cpu(core_domains, i).sd;
+ init_sched_groups_power(i, sd);
+ }
+#endif
+
+ for_each_cpu(i, cpu_map) {
+ sd = &per_cpu(phys_domains, i).sd;
+ init_sched_groups_power(i, sd);
+ }
+
+#ifdef CONFIG_NUMA
+ for (i = 0; i < nr_node_ids; i++)
+ init_numa_sched_groups_power(d.sched_group_nodes[i]);
+
+ if (d.sd_allnodes) {
+ struct sched_group *sg;
+
+ cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
+ d.tmpmask);
+ init_numa_sched_groups_power(sg);
+ }
+#endif
+
+ /* Attach the domains */
+ for_each_cpu(i, cpu_map) {
+#ifdef CONFIG_SCHED_SMT
+ sd = &per_cpu(cpu_domains, i).sd;
+#elif defined(CONFIG_SCHED_MC)
+ sd = &per_cpu(core_domains, i).sd;
+#else
+ sd = &per_cpu(phys_domains, i).sd;
+#endif
+ cpu_attach_domain(sd, d.rd, i);
+ }
+
+ d.sched_group_nodes = NULL; /* don't free this we still need it */
+ __free_domain_allocs(&d, sa_tmpmask, cpu_map);
+ return 0;
+
+error:
+ __free_domain_allocs(&d, alloc_state, cpu_map);
+ return -ENOMEM;
+}
+
+static int build_sched_domains(const struct cpumask *cpu_map)
+{
+ return __build_sched_domains(cpu_map, NULL);
+}
+
+static struct cpumask *doms_cur; /* current sched domains */
+static int ndoms_cur; /* number of sched domains in 'doms_cur' */
+static struct sched_domain_attr *dattr_cur;
+ /* attribues of custom domains in 'doms_cur' */
+
+/*
+ * Special case: If a kmalloc of a doms_cur partition (array of
+ * cpumask) fails, then fallback to a single sched domain,
+ * as determined by the single cpumask fallback_doms.
+ */
+static cpumask_var_t fallback_doms;
+
+/*
+ * arch_update_cpu_topology lets virtualised architectures update the
+ * cpu core maps. It is supposed to return 1 if the topology changed
+ * or 0 if it stayed the same.
+ */
+int __attribute__((weak)) arch_update_cpu_topology(void)
+{
+ return 0;
+}
+
+/*
+ * Set up scheduler domains and groups. Callers must hold the hotplug lock.
+ * For now this just excludes isolated cpus, but could be used to
+ * exclude other special cases in the future.
+ */
+static int arch_init_sched_domains(const struct cpumask *cpu_map)
+{
+ int err;
+
+ arch_update_cpu_topology();
+ ndoms_cur = 1;
+ doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
+ if (!doms_cur)
+ doms_cur = fallback_doms;
+ cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
+ dattr_cur = NULL;
+ err = build_sched_domains(doms_cur);
+ register_sched_domain_sysctl();
+
+ return err;
+}
+
+static void arch_destroy_sched_domains(const struct cpumask *cpu_map,
+ struct cpumask *tmpmask)
+{
+ free_sched_groups(cpu_map, tmpmask);
+}
+
+/*
+ * Detach sched domains from a group of cpus specified in cpu_map
+ * These cpus will now be attached to the NULL domain
+ */
+static void detach_destroy_domains(const struct cpumask *cpu_map)
+{
+ /* Save because hotplug lock held. */
+ static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
+ int i;
+
+ for_each_cpu(i, cpu_map)
+ cpu_attach_domain(NULL, &def_root_domain, i);
+ synchronize_sched();
+ arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask));
+}
+
+/* handle null as "default" */
+static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
+ struct sched_domain_attr *new, int idx_new)
+{
+ struct sched_domain_attr tmp;
+
+ /* fast path */
+ if (!new && !cur)
+ return 1;
+
+ tmp = SD_ATTR_INIT;
+ return !memcmp(cur ? (cur + idx_cur) : &tmp,
+ new ? (new + idx_new) : &tmp,
+ sizeof(struct sched_domain_attr));
+}
+
+/*
+ * Partition sched domains as specified by the 'ndoms_new'
+ * cpumasks in the array doms_new[] of cpumasks. This compares
+ * doms_new[] to the current sched domain partitioning, doms_cur[].
+ * It destroys each deleted domain and builds each new domain.
+ *
+ * 'doms_new' is an array of cpumask's of length 'ndoms_new'.
+ * The masks don't intersect (don't overlap.) We should setup one
+ * sched domain for each mask. CPUs not in any of the cpumasks will
+ * not be load balanced. If the same cpumask appears both in the
+ * current 'doms_cur' domains and in the new 'doms_new', we can leave
+ * it as it is.
+ *
+ * The passed in 'doms_new' should be kmalloc'd. This routine takes
+ * ownership of it and will kfree it when done with it. If the caller
+ * failed the kmalloc call, then it can pass in doms_new == NULL &&
+ * ndoms_new == 1, and partition_sched_domains() will fallback to
+ * the single partition 'fallback_doms', it also forces the domains
+ * to be rebuilt.
+ *
+ * If doms_new == NULL it will be replaced with cpu_online_mask.
+ * ndoms_new == 0 is a special case for destroying existing domains,
+ * and it will not create the default domain.
+ *
+ * Call with hotplug lock held
+ */
+/* FIXME: Change to struct cpumask *doms_new[] */
+void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
+ struct sched_domain_attr *dattr_new)
+{
+ int i, j, n;
+ int new_topology;
+
+ mutex_lock(&sched_domains_mutex);
+
+ /* always unregister in case we don't destroy any domains */
+ unregister_sched_domain_sysctl();
+
+ /* Let architecture update cpu core mappings. */
+ new_topology = arch_update_cpu_topology();
+
+ n = doms_new ? ndoms_new : 0;
+
+ /* Destroy deleted domains */
+ for (i = 0; i < ndoms_cur; i++) {
+ for (j = 0; j < n && !new_topology; j++) {
+ if (cpumask_equal(&doms_cur[i], &doms_new[j])
+ && dattrs_equal(dattr_cur, i, dattr_new, j))
+ goto match1;
+ }
+ /* no match - a current sched domain not in new doms_new[] */
+ detach_destroy_domains(doms_cur + i);
+match1:
+ ;
+ }
+
+ if (doms_new == NULL) {
+ ndoms_cur = 0;
+ doms_new = fallback_doms;
+ cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
+ WARN_ON_ONCE(dattr_new);
+ }
+
+ /* Build new domains */
+ for (i = 0; i < ndoms_new; i++) {
+ for (j = 0; j < ndoms_cur && !new_topology; j++) {
+ if (cpumask_equal(&doms_new[i], &doms_cur[j])
+ && dattrs_equal(dattr_new, i, dattr_cur, j))
+ goto match2;
+ }
+ /* no match - add a new doms_new */
+ __build_sched_domains(doms_new + i,
+ dattr_new ? dattr_new + i : NULL);
+match2:
+ ;
+ }
+
+ /* Remember the new sched domains */
+ if (doms_cur != fallback_doms)
+ kfree(doms_cur);
+ kfree(dattr_cur); /* kfree(NULL) is safe */
+ doms_cur = doms_new;
+ dattr_cur = dattr_new;
+ ndoms_cur = ndoms_new;
+
+ register_sched_domain_sysctl();
+
+ mutex_unlock(&sched_domains_mutex);
+}
+
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+static void arch_reinit_sched_domains(void)
+{
+ get_online_cpus();
+
+ /* Destroy domains first to force the rebuild */
+ partition_sched_domains(0, NULL, NULL);
+
+ rebuild_sched_domains();
+ put_online_cpus();
+}
+
+static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
+{
+ unsigned int level = 0;
+
+ if (sscanf(buf, "%u", &level) != 1)
+ return -EINVAL;
+
+ /*
+ * level is always be positive so don't check for
+ * level < POWERSAVINGS_BALANCE_NONE which is 0
+ * What happens on 0 or 1 byte write,
+ * need to check for count as well?
+ */
+
+ if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
+ return -EINVAL;
+
+ if (smt)
+ sched_smt_power_savings = level;
+ else
+ sched_mc_power_savings = level;
+
+ arch_reinit_sched_domains();
+
+ return count;
+}
+
+#ifdef CONFIG_SCHED_MC
+static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
+ char *page)
+{
+ return sprintf(page, "%u\n", sched_mc_power_savings);
+}
+static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
+ const char *buf, size_t count)
+{
+ return sched_power_savings_store(buf, count, 0);
+}
+static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
+ sched_mc_power_savings_show,
+ sched_mc_power_savings_store);
+#endif
+
+#ifdef CONFIG_SCHED_SMT
+static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
+ char *page)
+{
+ return sprintf(page, "%u\n", sched_smt_power_savings);
+}
+static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
+ const char *buf, size_t count)
+{
+ return sched_power_savings_store(buf, count, 1);
+}
+static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
+ sched_smt_power_savings_show,
+ sched_smt_power_savings_store);
+#endif
+
+int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
+{
+ int err = 0;
+
+#ifdef CONFIG_SCHED_SMT
+ if (smt_capable())
+ err = sysfs_create_file(&cls->kset.kobj,
+ &attr_sched_smt_power_savings.attr);
+#endif
+#ifdef CONFIG_SCHED_MC
+ if (!err && mc_capable())
+ err = sysfs_create_file(&cls->kset.kobj,
+ &attr_sched_mc_power_savings.attr);
+#endif
+ return err;
+}
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
+
+#ifndef CONFIG_CPUSETS
+/*
+ * Add online and remove offline CPUs from the scheduler domains.
+ * When cpusets are enabled they take over this function.
+ */
+static int update_sched_domains(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ partition_sched_domains(1, NULL, NULL);
+ return NOTIFY_OK;
+
+ default:
+ return NOTIFY_DONE;
+ }
+}
+#endif
+
+static int update_runtime(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ switch (action) {
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ return NOTIFY_OK;
+
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ return NOTIFY_OK;
+
+ default:
+ return NOTIFY_DONE;
+ }
+}
+
+#if defined(CONFIG_SCHED_SMT) || defined(CONFIG_SCHED_MC)
+/*
+ * Cheaper version of the below functions in case support for SMT and MC is
+ * compiled in but CPUs have no siblings.
+ */
+static int sole_cpu_idle(unsigned long cpu)
+{
+ return rq_idle(cpu_rq(cpu));
+}
+#endif
+#ifdef CONFIG_SCHED_SMT
+/* All this CPU's SMT siblings are idle */
+static int siblings_cpu_idle(unsigned long cpu)
+{
+ return cpumask_subset(&(cpu_rq(cpu)->smt_siblings),
+ &grq.cpu_idle_map);
+}
+#endif
+#ifdef CONFIG_SCHED_MC
+/* All this CPU's shared cache siblings are idle */
+static int cache_cpu_idle(unsigned long cpu)
+{
+ return cpumask_subset(&(cpu_rq(cpu)->cache_siblings),
+ &grq.cpu_idle_map);
+}
+#endif
+
+void __init sched_init_smp(void)
+{
+ struct sched_domain *sd;
+ int cpu, cpus;
+
+ cpumask_var_t non_isolated_cpus;
+
+ alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
+ alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
+
+#if defined(CONFIG_NUMA)
+ sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
+ GFP_KERNEL);
+ BUG_ON(sched_group_nodes_bycpu == NULL);
+#endif
+ get_online_cpus();
+ mutex_lock(&sched_domains_mutex);
+ arch_init_sched_domains(cpu_online_mask);
+ cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
+ if (cpumask_empty(non_isolated_cpus))
+ cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
+ mutex_unlock(&sched_domains_mutex);
+ put_online_cpus();
+
+#ifndef CONFIG_CPUSETS
+ /* XXX: Theoretical race here - CPU may be hotplugged now */
+ hotcpu_notifier(update_sched_domains, 0);
+#endif
+
+ /* RT runtime code needs to handle some hotplug events */
+ hotcpu_notifier(update_runtime, 0);
+
+ /* Move init over to a non-isolated CPU */
+ if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
+ BUG();
+ free_cpumask_var(non_isolated_cpus);
+
+ /*
+ * Assume that every added cpu gives us slightly less overall latency
+ * allowing us to increase the base rr_interval, non-linearly and with
+ * an upper bound.
+ */
+ cpus = num_online_cpus();
+ rr_interval = rr_interval * (4 * cpus + 4) / (cpus + 6);
+
+ grq_lock_irq();
+ /*
+ * Set up the relative cache distance of each online cpu from each
+ * other in a simple array for quick lookup. Locality is determined
+ * by the closest sched_domain that CPUs are separated by. CPUs with
+ * shared cache in SMT and MC are treated as local. Separate CPUs
+ * (within the same package or physically) within the same node are
+ * treated as not local. CPUs not even in the same domain (different
+ * nodes) are treated as very distant.
+ */
+ for_each_online_cpu(cpu) {
+ struct rq *rq = cpu_rq(cpu);
+ for_each_domain(cpu, sd) {
+ unsigned long locality;
+ int other_cpu;
+
+#ifdef CONFIG_SCHED_SMT
+ if (sd->level == SD_LV_SIBLING) {
+ for_each_cpu_mask(other_cpu, *sched_domain_span(sd))
+ cpumask_set_cpu(other_cpu, &rq->smt_siblings);
+ }
+#endif
+#ifdef CONFIG_SCHED_MC
+ if (sd->level == SD_LV_MC) {
+ for_each_cpu_mask(other_cpu, *sched_domain_span(sd))
+ cpumask_set_cpu(other_cpu, &rq->cache_siblings);
+ }
+#endif
+ if (sd->level <= SD_LV_MC)
+ locality = 0;
+ else if (sd->level <= SD_LV_NODE)
+ locality = 1;
+ else
+ continue;
+
+ for_each_cpu_mask(other_cpu, *sched_domain_span(sd)) {
+ if (locality < rq->cpu_locality[other_cpu])
+ rq->cpu_locality[other_cpu] = locality;
+ }
+ }
+
+/*
+ * Each runqueue has its own function in case it doesn't have
+ * siblings of its own allowing mixed topologies.
+ */
+#ifdef CONFIG_SCHED_SMT
+ if (cpus_weight(rq->smt_siblings) > 1)
+ rq->siblings_idle = siblings_cpu_idle;
+#endif
+#ifdef CONFIG_SCHED_MC
+ if (cpus_weight(rq->cache_siblings) > 1)
+ rq->cache_idle = cache_cpu_idle;
+#endif
+ }
+ grq_unlock_irq();
+}
+#else
+void __init sched_init_smp(void)
+{
+}
+#endif /* CONFIG_SMP */
+
+unsigned int sysctl_timer_migration = 1;
+
+int in_sched_functions(unsigned long addr)
+{
+ return in_lock_functions(addr) ||
+ (addr >= (unsigned long)__sched_text_start
+ && addr < (unsigned long)__sched_text_end);
+}
+
+void __init sched_init(void)
+{
+ int i;
+ struct rq *rq;
+
+ prio_ratios[0] = 128;
+ for (i = 1 ; i < PRIO_RANGE ; i++)
+ prio_ratios[i] = prio_ratios[i - 1] * 11 / 10;
+
+ spin_lock_init(&grq.lock);
+ grq.nr_running = grq.nr_uninterruptible = grq.nr_switches = 0;
+ grq.niffies = 0;
+ grq.last_jiffy = jiffies;
+ spin_lock_init(&grq.iso_lock);
+ grq.iso_ticks = grq.iso_refractory = 0;
+#ifdef CONFIG_SMP
+ init_defrootdomain();
+ grq.qnr = grq.idle_cpus = 0;
+ cpumask_clear(&grq.cpu_idle_map);
+#else
+ uprq = &per_cpu(runqueues, 0);
+#endif
+ for_each_possible_cpu(i) {
+ rq = cpu_rq(i);
+ rq->user_pc = rq->nice_pc = rq->softirq_pc = rq->system_pc =
+ rq->iowait_pc = rq->idle_pc = 0;
+ rq->dither = 0;
+#ifdef CONFIG_SMP
+ rq->last_niffy = 0;
+ rq->sd = NULL;
+ rq->rd = NULL;
+ rq->online = 0;
+ rq->cpu = i;
+ rq_attach_root(rq, &def_root_domain);
+#endif
+ atomic_set(&rq->nr_iowait, 0);
+ }
+
+#ifdef CONFIG_SMP
+ nr_cpu_ids = i;
+ /*
+ * Set the base locality for cpu cache distance calculation to
+ * "distant" (3). Make sure the distance from a CPU to itself is 0.
+ */
+ for_each_possible_cpu(i) {
+ int j;
+
+ rq = cpu_rq(i);
+#ifdef CONFIG_SCHED_SMT
+ cpumask_clear(&rq->smt_siblings);
+ cpumask_set_cpu(i, &rq->smt_siblings);
+ rq->siblings_idle = sole_cpu_idle;
+ cpumask_set_cpu(i, &rq->smt_siblings);
+#endif
+#ifdef CONFIG_SCHED_MC
+ cpumask_clear(&rq->cache_siblings);
+ cpumask_set_cpu(i, &rq->cache_siblings);
+ rq->cache_idle = sole_cpu_idle;
+ cpumask_set_cpu(i, &rq->cache_siblings);
+#endif
+ rq->cpu_locality = kmalloc(nr_cpu_ids * sizeof(unsigned long),
+ GFP_NOWAIT);
+ for_each_possible_cpu(j) {
+ if (i == j)
+ rq->cpu_locality[j] = 0;
+ else
+ rq->cpu_locality[j] = 3;
+ }
+ }
+#endif
+
+ for (i = 0; i < PRIO_LIMIT; i++)
+ INIT_LIST_HEAD(grq.queue + i);
+ /* delimiter for bitsearch */
+ __set_bit(PRIO_LIMIT, grq.prio_bitmap);
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+ INIT_HLIST_HEAD(&init_task.preempt_notifiers);
+#endif
+
+#ifdef CONFIG_RT_MUTEXES
+ plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
+#endif
+
+ /*
+ * The boot idle thread does lazy MMU switching as well:
+ */
+ atomic_inc(&init_mm.mm_count);
+ enter_lazy_tlb(&init_mm, current);
+
+ /*
+ * Make us the idle thread. Technically, schedule() should not be
+ * called from this thread, however somewhere below it might be,
+ * but because we are the idle thread, we just pick up running again
+ * when this runqueue becomes "idle".
+ */
+ init_idle(current, smp_processor_id());
+
+ /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
+ zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
+#ifdef CONFIG_SMP
+#ifdef CONFIG_NO_HZ
+ zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
+ alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
+#endif
+ zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+#endif /* SMP */
+ perf_event_init();
+}
+
+#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
+static inline int preempt_count_equals(int preempt_offset)
+{
+ int nested = preempt_count() & ~PREEMPT_ACTIVE;
+
+ return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
+}
+
+void __might_sleep(char *file, int line, int preempt_offset)
+{
+#ifdef in_atomic
+ static unsigned long prev_jiffy; /* ratelimiting */
+
+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+ system_state != SYSTEM_RUNNING || oops_in_progress)
+ return;
+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+ return;
+ prev_jiffy = jiffies;
+
+ printk(KERN_ERR
+ "BUG: sleeping function called from invalid context at %s:%d\n",
+ file, line);
+ printk(KERN_ERR
+ "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+ in_atomic(), irqs_disabled(),
+ current->pid, current->comm);
+
+ debug_show_held_locks(current);
+ if (irqs_disabled())
+ print_irqtrace_events(current);
+ dump_stack();
+#endif
+}
+EXPORT_SYMBOL(__might_sleep);
+#endif
+
+#ifdef CONFIG_MAGIC_SYSRQ
+void normalize_rt_tasks(void)
+{
+ struct task_struct *g, *p;
+ unsigned long flags;
+ struct rq *rq;
+ int queued;
+
+ read_lock_irq(&tasklist_lock);
+
+ do_each_thread(g, p) {
+ if (!rt_task(p) && !iso_task(p))
+ continue;
+
+ spin_lock_irqsave(&p->pi_lock, flags);
+ rq = __task_grq_lock(p);
+
+ queued = task_queued(p);
+ if (queued)
+ dequeue_task(p);
+ __setscheduler(p, rq, SCHED_NORMAL, 0);
+ if (queued) {
+ enqueue_task(p);
+ try_preempt(p, rq);
+ }
+
+ __task_grq_unlock();
+ spin_unlock_irqrestore(&p->pi_lock, flags);
+ } while_each_thread(g, p);
+
+ read_unlock_irq(&tasklist_lock);
+}
+#endif /* CONFIG_MAGIC_SYSRQ */
+
+#ifdef CONFIG_IA64
+/*
+ * These functions are only useful for the IA64 MCA handling.
+ *
+ * They can only be called when the whole system has been
+ * stopped - every CPU needs to be quiescent, and no scheduling
+ * activity can take place. Using them for anything else would
+ * be a serious bug, and as a result, they aren't even visible
+ * under any other configuration.
+ */
+
+/**
+ * curr_task - return the current task for a given cpu.
+ * @cpu: the processor in question.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+struct task_struct *curr_task(int cpu)
+{
+ return cpu_curr(cpu);
+}
+
+/**
+ * set_curr_task - set the current task for a given cpu.
+ * @cpu: the processor in question.
+ * @p: the task pointer to set.
+ *
+ * Description: This function must only be used when non-maskable interrupts
+ * are serviced on a separate stack. It allows the architecture to switch the
+ * notion of the current task on a cpu in a non-blocking manner. This function
+ * must be called with all CPU's synchronised, and interrupts disabled, the
+ * and caller must save the original value of the current task (see
+ * curr_task() above) and restore that value before reenabling interrupts and
+ * re-starting the system.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+void set_curr_task(int cpu, struct task_struct *p)
+{
+ cpu_curr(cpu) = p;
+}
+
+#endif
+
+/*
+ * Use precise platform statistics if available:
+ */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+cputime_t task_utime(struct task_struct *p)
+{
+ return p->utime;
+}
+
+cputime_t task_stime(struct task_struct *p)
+{
+ return p->stime;
+}
+
+void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputime(p, &cputime);
+
+ *ut = cputime.utime;
+ *st = cputime.stime;
+}
+#else
+
+#ifndef nsecs_to_cputime
+/**
+ * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
+ *
+ * @n: nsecs in u64
+ *
+ * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
+ * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
+ * for scheduler, not for use in device drivers to calculate timeout value.
+ *
+ * note:
+ * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
+ * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
+ */
+static unsigned long nsecs_to_jiffies(u64 n)
+{
+#if (NSEC_PER_SEC % HZ) == 0
+ /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
+ return div_u64(n, NSEC_PER_SEC / HZ);
+#elif (HZ % 512) == 0
+ /* overflow after 292 years if HZ = 1024 */
+ return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
+#else
+ /*
+ * Generic case - optimized for cases where HZ is a multiple of 3.
+ * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
+ */
+ return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
+#endif
+}
+
+# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
+#endif
+
+cputime_t task_utime(struct task_struct *p)
+{
+ clock_t utime = cputime_to_clock_t(p->utime),
+ total = utime + cputime_to_clock_t(p->stime);
+ u64 temp;
+
+ temp = (u64)nsec_to_clock_t(p->sched_time);
+
+ if (total) {
+ temp *= utime;
+ do_div(temp, total);
+ }
+ utime = (clock_t)temp;
+
+ p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
+ return p->prev_utime;
+}
+
+cputime_t task_stime(struct task_struct *p)
+{
+ clock_t stime;
+
+ stime = nsec_to_clock_t(p->sched_time) -
+ cputime_to_clock_t(task_utime(p));
+
+ if (stime >= 0)
+ p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
+
+ return p->prev_stime;
+}
+
+/*
+ * Must be called with siglock held.
+ */
+void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ struct signal_struct *sig = p->signal;
+ struct task_cputime cputime;
+ cputime_t rtime, utime, total;
+
+ thread_group_cputime(p, &cputime);
+
+ total = cputime_add(cputime.utime, cputime.stime);
+ rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
+
+ if (total) {
+ u64 temp;
+
+ temp = (u64)(rtime * cputime.utime);
+ do_div(temp, total);
+ utime = (cputime_t)temp;
+ } else
+ utime = rtime;
+
+ sig->prev_utime = max(sig->prev_utime, utime);
+ sig->prev_stime = max(sig->prev_stime,
+ cputime_sub(rtime, sig->prev_utime));
+
+ *ut = sig->prev_utime;
+ *st = sig->prev_stime;
+}
+#endif
+
+inline cputime_t task_gtime(struct task_struct *p)
+{
+ return p->gtime;
+}
+
+void __cpuinit init_idle_bootup_task(struct task_struct *idle)
+{}
+
+#ifdef CONFIG_SCHED_DEBUG
+void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
+{}
+
+void proc_sched_set_task(struct task_struct *p)
+{}
+#endif
+
+/* No RCU torture test support */
+void synchronize_sched_expedited(void)
+{
+ barrier();
+}
+EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
+
+#ifdef CONFIG_SMP
+unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+ return SCHED_LOAD_SCALE;
+}
+
+unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+ unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long smt_gain = sd->smt_gain;
+
+ smt_gain /= weight;
+
+ return smt_gain;
+}
+#endif
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -106,7 +106,12 @@ static int zero;
static int __maybe_unused one = 1;
static int __maybe_unused two = 2;
static unsigned long one_ul = 1;
-static int one_hundred = 100;
+static int __maybe_unused one_hundred = 100;
+#ifdef CONFIG_SCHED_BFS
+extern int rr_interval;
+extern int sched_iso_cpu;
+static int __read_mostly one_thousand = 1000;
+#endif
#ifdef CONFIG_PRINTK
static int ten_thousand = 10000;
#endif
@@ -244,7 +249,7 @@ static struct ctl_table root_table[] = {
{ .ctl_name = 0 }
};
-#ifdef CONFIG_SCHED_DEBUG
+#if defined(CONFIG_SCHED_DEBUG) && !defined(CONFIG_SCHED_BFS)
static int min_sched_granularity_ns = 100000; /* 100 usecs */
static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_wakeup_granularity_ns; /* 0 usecs */
@@ -252,6 +257,7 @@ static int max_wakeup_granularity_ns = N
#endif
static struct ctl_table kern_table[] = {
+#ifndef CONFIG_SCHED_BFS
{
.ctl_name = CTL_UNNUMBERED,
.procname = "sched_child_runs_first",
@@ -380,6 +386,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+#endif /* !CONFIG_SCHED_BFS */
#ifdef CONFIG_SCHED_AUTOGROUP
{
.ctl_name = CTL_UNNUMBERED,
@@ -843,6 +850,30 @@ static struct ctl_table kern_table[] = {
.proc_handler = &proc_dointvec,
},
#endif
+#ifdef CONFIG_SCHED_BFS
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "rr_interval",
+ .data = &rr_interval,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &one,
+ .extra2 = &one_thousand,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "iso_cpu",
+ .data = &sched_iso_cpu,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ .extra2 = &one_hundred,
+ },
+#endif
#if defined(CONFIG_S390) && defined(CONFIG_SMP)
{
.ctl_name = KERN_SPIN_RETRY,
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -718,7 +718,7 @@ config BOOT_PRINTK_DELAY
config RCU_TORTURE_TEST
tristate "torture tests for RCU"
- depends on DEBUG_KERNEL
+ depends on DEBUG_KERNEL && !SCHED_BFS
default n
help
This option provides a kernel module that runs torture tests
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -454,8 +454,8 @@ out:
}
EXPORT_SYMBOL(add_to_page_cache_locked);
-int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
- pgoff_t offset, gfp_t gfp_mask)
+int __add_to_page_cache_lru(struct page *page, struct address_space *mapping,
+ pgoff_t offset, gfp_t gfp_mask, int tail)
{
int ret;
@@ -471,12 +471,19 @@ int add_to_page_cache_lru(struct page *p
ret = add_to_page_cache(page, mapping, offset, gfp_mask);
if (ret == 0) {
if (page_is_file_cache(page))
- lru_cache_add_file(page);
+ lru_cache_add_file(page, tail);
else
lru_cache_add_anon(page);
}
return ret;
}
+
+int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
+ pgoff_t offset, gfp_t gfp_mask)
+{
+ return __add_to_page_cache_lru(page, mapping, offset, gfp_mask, 0);
+}
+
EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
#ifdef CONFIG_NUMA
@@ -970,6 +977,28 @@ static void shrink_readahead_size_eio(st
ra->ra_pages /= 4;
}
+static inline int nr_mapped(void)
+{
+ return global_page_state(NR_FILE_MAPPED) +
+ global_page_state(NR_ANON_PAGES);
+}
+
+/*
+ * This examines how large in pages a file size is and returns 1 if it is
+ * more than half the unmapped ram. Avoid doing read_page_state which is
+ * expensive unless we already know it is likely to be large enough.
+ */
+static int large_isize(unsigned long nr_pages)
+{
+ if (nr_pages * 6 > vm_total_pages) {
+ unsigned long unmapped_ram = vm_total_pages - nr_mapped();
+
+ if (nr_pages * 2 > unmapped_ram)
+ return 1;
+ }
+ return 0;
+}
+
/**
* do_generic_file_read - generic file read routine
* @filp: the file to read
@@ -994,7 +1023,7 @@ static void do_generic_file_read(struct
pgoff_t prev_index;
unsigned long offset; /* offset into pagecache page */
unsigned int prev_offset;
- int error;
+ int error, tail = 0;
index = *ppos >> PAGE_CACHE_SHIFT;
prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT;
@@ -1005,7 +1034,7 @@ static void do_generic_file_read(struct
for (;;) {
struct page *page;
pgoff_t end_index;
- loff_t isize;
+ loff_t isize = 0;
unsigned long nr, ret;
cond_resched();
@@ -1179,8 +1208,16 @@ no_cached_page:
desc->error = -ENOMEM;
goto out;
}
- error = add_to_page_cache_lru(page, mapping,
- index, GFP_KERNEL);
+ /*
+ * If we know the file is large we add the pages read to the
+ * end of the lru as we're unlikely to be able to cache the
+ * whole file in ram so make those pages the first to be
+ * dropped if not referenced soon.
+ */
+ if (large_isize(end_index))
+ tail = 1;
+ error = __add_to_page_cache_lru(page, mapping,
+ index, GFP_KERNEL, tail);
if (error) {
page_cache_release(page);
if (error == -EEXIST)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -365,7 +365,7 @@ static void __oom_kill_task(struct task_
* all the memory it needs. That way it should be able to
* exit() and clear out its resources quickly...
*/
- p->rt.time_slice = HZ;
+ set_oom_timeslice(p);
set_tsk_thread_flag(p, TIF_MEMDIE);
force_sig(SIGKILL, p);
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1770,13 +1770,13 @@ __alloc_pages_high_priority(gfp_t gfp_ma
static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
- enum zone_type high_zoneidx)
+ enum zone_type high_zoneidx, struct task_struct *p)
{
struct zoneref *z;
struct zone *zone;
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
- wakeup_kswapd(zone, order);
+ wakeup_kswapd(zone, order, p);
}
static inline int
@@ -1853,7 +1853,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u
goto nopage;
restart:
- wake_all_kswapd(order, zonelist, high_zoneidx);
+ wake_all_kswapd(order, zonelist, high_zoneidx, p);
/*
* OK, we're below the kswapd watermark and have kicked background
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -214,22 +214,29 @@ void mark_page_accessed(struct page *pag
EXPORT_SYMBOL(mark_page_accessed);
-void __lru_cache_add(struct page *page, enum lru_list lru)
+void ______pagevec_lru_add(struct pagevec *pvec, enum lru_list lru, int tail);
+
+void ____lru_cache_add(struct page *page, enum lru_list lru, int tail)
{
struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru];
page_cache_get(page);
if (!pagevec_add(pvec, page))
- ____pagevec_lru_add(pvec, lru);
+ ______pagevec_lru_add(pvec, lru, tail);
put_cpu_var(lru_add_pvecs);
}
+void __lru_cache_add(struct page *page, enum lru_list lru)
+{
+ ____lru_cache_add(page, lru, 0);
+}
+
/**
* lru_cache_add_lru - add a page to a page list
* @page: the page to be added to the LRU.
* @lru: the LRU list to which the page is added.
*/
-void lru_cache_add_lru(struct page *page, enum lru_list lru)
+void __lru_cache_add_lru(struct page *page, enum lru_list lru, int tail)
{
if (PageActive(page)) {
VM_BUG_ON(PageUnevictable(page));
@@ -240,7 +247,12 @@ void lru_cache_add_lru(struct page *page
}
VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page));
- __lru_cache_add(page, lru);
+ ____lru_cache_add(page, lru, tail);
+}
+
+void lru_cache_add_lru(struct page *page, enum lru_list lru)
+{
+ __lru_cache_add_lru(page, lru, 0);
}
/**
@@ -400,7 +412,7 @@ EXPORT_SYMBOL(__pagevec_release);
* Add the passed pages to the LRU, then drop the caller's refcount
* on them. Reinitialises the caller's pagevec.
*/
-void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+void ______pagevec_lru_add(struct pagevec *pvec, enum lru_list lru, int tail)
{
int i;
struct zone *zone = NULL;
@@ -428,7 +440,7 @@ void ____pagevec_lru_add(struct pagevec
if (active)
SetPageActive(page);
update_page_reclaim_stat(zone, page, file, active);
- add_page_to_lru_list(zone, page, lru);
+ __add_page_to_lru_list(zone, page, lru, tail);
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
@@ -436,6 +448,11 @@ void ____pagevec_lru_add(struct pagevec
pagevec_reinit(pvec);
}
+void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
+{
+ ______pagevec_lru_add(pvec, lru, 0);
+}
+
EXPORT_SYMBOL(____pagevec_lru_add);
/*
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -36,6 +36,7 @@
#include <linux/rwsem.h>
#include <linux/delay.h>
#include <linux/kthread.h>
+#include <linux/timer.h>
#include <linux/freezer.h>
#include <linux/memcontrol.h>
#include <linux/delayacct.h>
@@ -1640,6 +1641,7 @@ static void shrink_zone(int priority, st
unsigned long swap_cluster_max = sc->swap_cluster_max;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
int noswap = 0;
+ int tmp_priority;
/* If we have no swap space, do not bother scanning anon pages. */
if (!sc->may_swap || (nr_swap_pages <= 0)) {
@@ -1655,7 +1657,11 @@ static void shrink_zone(int priority, st
scan = zone_nr_lru_pages(zone, sc, l);
if (priority || noswap) {
- scan >>= priority;
+ tmp_priority = priority;
+
+ if (file && priority > 0)
+ tmp_priority = DEF_PRIORITY;
+ scan >>= tmp_priority;
scan = (scan * percent[file]) / 100;
}
nr[l] = nr_scan_try_batch(scan,
@@ -1700,6 +1706,38 @@ static void shrink_zone(int priority, st
}
/*
+ * Helper functions to adjust nice level of kswapd, based on the priority of
+ * the task (p) that called it. If it is already higher priority we do not
+ * demote its nice level since it is still working on behalf of a higher
+ * priority task. With kernel threads we leave it at nice 0.
+ *
+ * We don't ever run kswapd real time, so if a real time task calls kswapd we
+ * set it to highest SCHED_NORMAL priority.
+ */
+static int effective_sc_prio(struct task_struct *p)
+{
+ if (likely(p->mm)) {
+ if (rt_task(p))
+ return -20;
+#ifdef CONFIG_SCHED_BFS
+ if (p->policy == SCHED_IDLEPRIO)
+ return 19;
+#endif
+ return task_nice(p);
+ }
+ return 0;
+}
+
+static void set_kswapd_nice(struct task_struct *kswapd, struct task_struct *p,
+ int active)
+{
+ long nice = effective_sc_prio(p);
+
+ if (task_nice(kswapd) > nice || !active)
+ set_user_nice(kswapd, nice);
+}
+
+/*
* This is the direct reclaim path, for page-allocating processes. We only
* try to reclaim pages from zones which will satisfy the caller's allocation
* request.
@@ -2168,6 +2206,8 @@ out:
return sc.nr_reclaimed;
}
+#define WT_EXPIRY (HZ * 5) /* Time to wakeup watermark_timer */
+
/*
* The background pageout daemon, started as a kernel thread
* from the init process.
@@ -2217,6 +2257,8 @@ static int kswapd(void *p)
for ( ; ; ) {
unsigned long new_order;
+ /* kswapd has been busy so delay watermark_timer */
+ mod_timer(&pgdat->watermark_timer, jiffies + WT_EXPIRY);
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
new_order = pgdat->kswapd_max_order;
pgdat->kswapd_max_order = 0;
@@ -2230,6 +2272,7 @@ static int kswapd(void *p)
if (!freezing(current))
schedule();
+ set_user_nice(tsk, 0);
order = pgdat->kswapd_max_order;
}
finish_wait(&pgdat->kswapd_wait, &wait);
@@ -2247,9 +2290,10 @@ static int kswapd(void *p)
/*
* A zone is low on free memory, so wake its kswapd task to service it.
*/
-void wakeup_kswapd(struct zone *zone, int order)
+void wakeup_kswapd(struct zone *zone, int order, struct task_struct *p)
{
pg_data_t *pgdat;
+ int active;
if (!populated_zone(zone))
return;
@@ -2261,7 +2305,9 @@ void wakeup_kswapd(struct zone *zone, in
pgdat->kswapd_max_order = order;
if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
return;
- if (!waitqueue_active(&pgdat->kswapd_wait))
+ active = waitqueue_active(&pgdat->kswapd_wait);
+ set_kswapd_nice(pgdat->kswapd, p, active);
+ if (!active)
return;
wake_up_interruptible(&pgdat->kswapd_wait);
}
@@ -2473,20 +2519,61 @@ static int __devinit cpu_callback(struct
}
/*
+ * We wake up kswapd every WT_EXPIRY till free ram is above pages_lots
+ */
+static void watermark_wakeup(unsigned long data)
+{
+ pg_data_t *pgdat = (pg_data_t *)data;
+ struct timer_list *wt = &pgdat->watermark_timer;
+ int i;
+
+#ifdef CONFIG_SCHED_BFS
+ if (!waitqueue_active(&pgdat->kswapd_wait) || above_background_load())
+#else
+ if (!waitqueue_active(&pgdat->kswapd_wait))
+#endif
+ goto out;
+ for (i = pgdat->nr_zones - 1; i >= 0; i--) {
+ struct zone *z = pgdat->node_zones + i;
+
+ if (!populated_zone(z) || is_highmem(z)) {
+ /* We are better off leaving highmem full */
+ continue;
+ }
+ if (!zone_watermark_ok(z, 0, lots_wmark_pages(z), 0, 0)) {
+ wake_up_interruptible(&pgdat->kswapd_wait);
+ goto out;
+ }
+ }
+out:
+ mod_timer(wt, jiffies + WT_EXPIRY);
+ return;
+}
+
+/*
* This kswapd start function will be called by init and node-hot-add.
* On node-hot-add, kswapd will moved to proper cpus if cpus are hot-added.
*/
int kswapd_run(int nid)
{
pg_data_t *pgdat = NODE_DATA(nid);
+ struct timer_list *wt;
int ret = 0;
if (pgdat->kswapd)
return 0;
+ wt = &pgdat->watermark_timer;
+ init_timer(wt);
+ wt->data = (unsigned long)pgdat;
+ wt->function = watermark_wakeup;
+ wt->expires = jiffies + WT_EXPIRY;
+ add_timer(wt);
+
pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
if (IS_ERR(pgdat->kswapd)) {
/* failure at boot is fatal */
+ del_timer(wt);
BUG_ON(system_state == SYSTEM_BOOTING);
printk("Failed to start kswapd on node %d\n",nid);
ret = -1;
projects / ziggy471-frankenstein-kernel.git / commitdiff