--- kernel/sched.c
+++ kernel/sched.c
@@ -1,3 +1,6 @@
+#ifdef CONFIG_SCHED_BFS
+#include "sched_bfs.c"
+#else
/*
* kernel/sched.c
*
@@ -76,6 +79,7 @@
#include <asm/irq_regs.h>
#include "sched_cpupri.h"
+#include "sched_autogroup.h"
#define CREATE_TRACE_POINTS
#include <trace/events/sched.h>
@@ -352,13 +356,20 @@ static inline struct task_group *task_gr
rcu_read_lock();
tg = __task_cred(p)->user->tg;
rcu_read_unlock();
+
+ return tg;
#elif defined(CONFIG_CGROUP_SCHED)
- tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
- struct task_group, css);
+ struct cgroup_subsys_state *css;
+
+ css = task_subsys_state(p, cpu_cgroup_subsys_id);
+ tg = container_of(css, struct task_group, css);
+
+ return autogroup_task_group(p, tg);
#else
tg = &init_task_group;
-#endif
+
return tg;
+#endif
}
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
@@ -542,7 +553,6 @@ struct rq {
struct load_weight load;
unsigned long nr_load_updates;
u64 nr_switches;
- u64 nr_migrations_in;
struct cfs_rq cfs;
struct rt_rq rt;
@@ -742,7 +752,7 @@ sched_feat_write(struct file *filp, cons
size_t cnt, loff_t *ppos)
{
char buf[64];
- char *cmp = buf;
+ char *cmp;
int neg = 0;
int i;
@@ -753,6 +763,7 @@ sched_feat_write(struct file *filp, cons
return -EFAULT;
buf[cnt] = 0;
+ cmp = strstrip(buf);
if (strncmp(buf, "NO_", 3) == 0) {
neg = 1;
@@ -760,9 +771,7 @@ sched_feat_write(struct file *filp, cons
}
for (i = 0; sched_feat_names[i]; i++) {
- int len = strlen(sched_feat_names[i]);
-
- if (strncmp(cmp, sched_feat_names[i], len) == 0) {
+ if (strcmp(cmp, sched_feat_names[i]) == 0) {
if (neg)
sysctl_sched_features &= ~(1UL << i);
else
@@ -943,14 +952,25 @@ static inline void finish_lock_switch(st
#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
/*
+ * Check whether the task is waking, we use this to synchronize ->cpus_allowed
+ * against ttwu().
+ */
+static inline int task_is_waking(struct task_struct *p)
+{
+ return unlikely(p->state == TASK_WAKING);
+}
+
+/*
* __task_rq_lock - lock the runqueue a given task resides on.
* Must be called interrupts disabled.
*/
static inline struct rq *__task_rq_lock(struct task_struct *p)
__acquires(rq->lock)
{
+ struct rq *rq;
+
for (;;) {
- struct rq *rq = task_rq(p);
+ rq = task_rq(p);
spin_lock(&rq->lock);
if (likely(rq == task_rq(p)))
return rq;
@@ -1623,7 +1643,7 @@ static void update_group_shares_cpu(stru
*/
static int tg_shares_up(struct task_group *tg, void *data)
{
- unsigned long weight, rq_weight = 0, shares = 0;
+ unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
unsigned long *usd_rq_weight;
struct sched_domain *sd = data;
unsigned long flags;
@@ -1639,6 +1659,7 @@ static int tg_shares_up(struct task_grou
weight = tg->cfs_rq[i]->load.weight;
usd_rq_weight[i] = weight;
+ rq_weight += weight;
/*
* If there are currently no tasks on the cpu pretend there
* is one of average load so that when a new task gets to
@@ -1647,10 +1668,13 @@ static int tg_shares_up(struct task_grou
if (!weight)
weight = NICE_0_LOAD;
- rq_weight += weight;
+ sum_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
+ if (!rq_weight)
+ rq_weight = sum_weight;
+
if ((!shares && rq_weight) || shares > tg->shares)
shares = tg->shares;
@@ -1818,10 +1842,25 @@ static void cfs_rq_set_shares(struct cfs
static void calc_load_account_active(struct rq *this_rq);
static void update_sysctl(void);
+static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
+{
+ set_task_rq(p, cpu);
+#ifdef CONFIG_SMP
+ /*
+ * After ->cpu is set up to a new value, task_rq_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
+}
+
#include "sched_stats.h"
#include "sched_idletask.c"
#include "sched_fair.c"
#include "sched_rt.c"
+#include "sched_autogroup.c"
#ifdef CONFIG_SCHED_DEBUG
# include "sched_debug.c"
#endif
@@ -1867,13 +1906,14 @@ static void update_avg(u64 *avg, u64 sam
*avg += diff >> 3;
}
-static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
+static void
+enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
{
if (wakeup)
p->se.start_runtime = p->se.sum_exec_runtime;
sched_info_queued(p);
- p->sched_class->enqueue_task(rq, p, wakeup);
+ p->sched_class->enqueue_task(rq, p, wakeup, head);
p->se.on_rq = 1;
}
@@ -1949,7 +1989,7 @@ static void activate_task(struct rq *rq,
if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
- enqueue_task(rq, p, wakeup);
+ enqueue_task(rq, p, wakeup, false);
inc_nr_running(rq);
}
@@ -1974,20 +2014,6 @@ inline int task_curr(const struct task_s
return cpu_curr(task_cpu(p)) == p;
}
-static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
-{
- set_task_rq(p, cpu);
-#ifdef CONFIG_SMP
- /*
- * After ->cpu is set up to a new value, task_rq_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
-}
-
static inline void check_class_changed(struct rq *rq, struct task_struct *p,
const struct sched_class *prev_class,
int oldprio, int running)
@@ -2014,21 +2040,15 @@ static inline void check_class_changed(s
*/
void kthread_bind(struct task_struct *p, unsigned int cpu)
{
- struct rq *rq = cpu_rq(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;
}
- spin_lock_irqsave(&rq->lock, flags);
- set_task_cpu(p, cpu);
p->cpus_allowed = cpumask_of_cpu(cpu);
p->rt.nr_cpus_allowed = 1;
p->flags |= PF_THREAD_BOUND;
- spin_unlock_irqrestore(&rq->lock, flags);
}
EXPORT_SYMBOL(kthread_bind);
@@ -2066,35 +2086,23 @@ task_hot(struct task_struct *p, u64 now,
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
int old_cpu = task_cpu(p);
- struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
- struct cfs_rq *old_cfsrq = task_cfs_rq(p),
- *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
- u64 clock_offset;
- clock_offset = old_rq->clock - new_rq->clock;
+#ifdef CONFIG_SCHED_DEBUG
+ /*
+ * We should never call set_task_cpu() on a blocked task,
+ * ttwu() will sort out the placement.
+ */
+ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
+ !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
+#endif
trace_sched_migrate_task(p, new_cpu);
-#ifdef CONFIG_SCHEDSTATS
- if (p->se.wait_start)
- p->se.wait_start -= clock_offset;
- if (p->se.sleep_start)
- p->se.sleep_start -= clock_offset;
- if (p->se.block_start)
- p->se.block_start -= clock_offset;
-#endif
if (old_cpu != new_cpu) {
p->se.nr_migrations++;
- new_rq->nr_migrations_in++;
-#ifdef CONFIG_SCHEDSTATS
- if (task_hot(p, old_rq->clock, NULL))
- schedstat_inc(p, se.nr_forced2_migrations);
-#endif
perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
1, 1, NULL, 0);
}
- p->se.vruntime -= old_cfsrq->min_vruntime -
- new_cfsrq->min_vruntime;
__set_task_cpu(p, new_cpu);
}
@@ -2327,6 +2335,69 @@ void task_oncpu_function_call(struct tas
preempt_enable();
}
+#ifdef CONFIG_SMP
+/*
+ * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held.
+ */
+static int select_fallback_rq(int cpu, struct task_struct *p)
+{
+ int dest_cpu;
+ const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+
+ /* Look for allowed, online CPU in same node. */
+ for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
+ if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+ return dest_cpu;
+
+ /* Any allowed, online CPU? */
+ dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
+ if (dest_cpu < nr_cpu_ids)
+ return dest_cpu;
+
+ /* No more Mr. Nice Guy. */
+ if (unlikely(dest_cpu >= nr_cpu_ids)) {
+ dest_cpu = cpuset_cpus_allowed_fallback(p);
+ /*
+ * Don't tell them about moving exiting tasks or
+ * kernel threads (both mm NULL), since they never
+ * leave kernel.
+ */
+ if (p->mm && printk_ratelimit()) {
+ printk(KERN_INFO "process %d (%s) no "
+ "longer affine to cpu%d\n",
+ task_pid_nr(p), p->comm, cpu);
+ }
+ }
+
+ return dest_cpu;
+}
+
+/*
+ * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable.
+ */
+static inline
+int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags)
+{
+ int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags);
+
+ /*
+ * In order not to call set_task_cpu() on a blocking task we need
+ * to rely on ttwu() to place the task on a valid ->cpus_allowed
+ * cpu.
+ *
+ * Since this is common to all placement strategies, this lives here.
+ *
+ * [ this allows ->select_task() to simply return task_cpu(p) and
+ * not worry about this generic constraint ]
+ */
+ if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
+ !cpu_online(cpu)))
+ cpu = select_fallback_rq(task_cpu(p), p);
+
+ return cpu;
+}
+#endif
+
/***
* try_to_wake_up - wake up a thread
* @p: the to-be-woken-up thread
@@ -2375,22 +2446,34 @@ static int try_to_wake_up(struct task_st
*
* First fix up the nr_uninterruptible count:
*/
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible--;
+ if (task_contributes_to_load(p)) {
+ if (likely(cpu_online(orig_cpu)))
+ rq->nr_uninterruptible--;
+ else
+ this_rq()->nr_uninterruptible--;
+ }
p->state = TASK_WAKING;
- task_rq_unlock(rq, &flags);
- cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+ if (p->sched_class->task_waking)
+ p->sched_class->task_waking(rq, p);
+
+ cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu)
set_task_cpu(p, cpu);
+ __task_rq_unlock(rq);
- rq = task_rq_lock(p, &flags);
-
- if (rq != orig_rq)
- update_rq_clock(rq);
+ rq = cpu_rq(cpu);
+ spin_lock(&rq->lock);
+ update_rq_clock(rq);
+ /*
+ * We migrated the task without holding either rq->lock, however
+ * since the task is not on the task list itself, nobody else
+ * will try and migrate the task, hence the rq should match the
+ * cpu we just moved it to.
+ */
+ WARN_ON(task_cpu(p) != cpu);
WARN_ON(p->state != TASK_WAKING);
- cpu = task_cpu(p);
#ifdef CONFIG_SCHEDSTATS
schedstat_inc(rq, ttwu_count);
@@ -2443,8 +2526,8 @@ out_running:
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
- if (p->sched_class->task_wake_up)
- p->sched_class->task_wake_up(rq, p);
+ if (p->sched_class->task_woken)
+ p->sched_class->task_woken(rq, p);
if (unlikely(rq->idle_stamp)) {
u64 delta = rq->clock - rq->idle_stamp;
@@ -2524,7 +2607,6 @@ static void __sched_fork(struct task_str
p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0;
- p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0;
@@ -2545,14 +2627,6 @@ static void __sched_fork(struct task_str
#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;
}
/*
@@ -2563,6 +2637,12 @@ void sched_fork(struct task_struct *p, i
int cpu = get_cpu();
__sched_fork(p);
+ /*
+ * We mark the process as running here. 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;
/*
* Revert to default priority/policy on fork if requested.
@@ -2594,9 +2674,9 @@ void sched_fork(struct task_struct *p, i
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
-#ifdef CONFIG_SMP
- cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
-#endif
+ if (p->sched_class->task_fork)
+ p->sched_class->task_fork(p);
+
set_task_cpu(p, cpu);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
@@ -2626,28 +2706,38 @@ void wake_up_new_task(struct task_struct
{
unsigned long flags;
struct rq *rq;
+ int cpu = get_cpu();
+#ifdef CONFIG_SMP
rq = task_rq_lock(p, &flags);
- BUG_ON(p->state != TASK_RUNNING);
- update_rq_clock(rq);
+ p->state = TASK_WAKING;
- if (!p->sched_class->task_new || !current->se.on_rq) {
- activate_task(rq, p, 0);
- } else {
- /*
- * Let the scheduling class do new task startup
- * management (if any):
- */
- p->sched_class->task_new(rq, p);
- inc_nr_running(rq);
- }
+ /*
+ * Fork balancing, do it here and not earlier because:
+ * - cpus_allowed can change in the fork path
+ * - any previously selected cpu might disappear through hotplug
+ *
+ * We set TASK_WAKING so that select_task_rq() can drop rq->lock
+ * without people poking at ->cpus_allowed.
+ */
+ cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0);
+ set_task_cpu(p, cpu);
+
+ p->state = TASK_RUNNING;
+ task_rq_unlock(rq, &flags);
+#endif
+
+ rq = task_rq_lock(p, &flags);
+ update_rq_clock(rq);
+ activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
- if (p->sched_class->task_wake_up)
- p->sched_class->task_wake_up(rq, p);
+ if (p->sched_class->task_woken)
+ p->sched_class->task_woken(rq, p);
#endif
task_rq_unlock(rq, &flags);
+ put_cpu();
}
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -3034,15 +3124,6 @@ static void calc_load_account_active(str
}
/*
- * Externally visible per-cpu scheduler statistics:
- * cpu_nr_migrations(cpu) - number of migrations into that cpu
- */
-u64 cpu_nr_migrations(int cpu)
-{
- return cpu_rq(cpu)->nr_migrations_in;
-}
-
-/*
* Update rq->cpu_load[] statistics. This function is usually called every
* scheduler tick (TICK_NSEC).
*/
@@ -3124,24 +3205,28 @@ static void double_rq_unlock(struct rq *
}
/*
- * If dest_cpu is allowed for this process, migrate the task to it.
- * This is accomplished by forcing the cpu_allowed mask to only
- * allow dest_cpu, which will force the cpu onto dest_cpu. Then
- * the cpu_allowed mask is restored.
+ * sched_exec - execve() is a valuable balancing opportunity, because at
+ * this point the task has the smallest effective memory and cache footprint.
*/
-static void sched_migrate_task(struct task_struct *p, int dest_cpu)
+void sched_exec(void)
{
+ struct task_struct *p = current;
struct migration_req req;
unsigned long flags;
struct rq *rq;
+ int dest_cpu;
rq = task_rq_lock(p, &flags);
- if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)
- || unlikely(!cpu_active(dest_cpu)))
- goto out;
+ dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0);
+ if (dest_cpu == smp_processor_id())
+ goto unlock;
- /* force the process onto the specified CPU */
- if (migrate_task(p, dest_cpu, &req)) {
+ /*
+ * select_task_rq() can race against ->cpus_allowed
+ */
+ if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) &&
+ likely(cpu_active(dest_cpu)) &&
+ migrate_task(p, dest_cpu, &req)) {
/* Need to wait for migration thread (might exit: take ref). */
struct task_struct *mt = rq->migration_thread;
@@ -3153,24 +3238,11 @@ static void sched_migrate_task(struct ta
return;
}
-out:
+unlock:
task_rq_unlock(rq, &flags);
}
/*
- * sched_exec - execve() is a valuable balancing opportunity, because at
- * this point the task has the smallest effective memory and cache footprint.
- */
-void sched_exec(void)
-{
- int new_cpu, this_cpu = get_cpu();
- new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0);
- put_cpu();
- if (new_cpu != this_cpu)
- sched_migrate_task(current, new_cpu);
-}
-
-/*
* pull_task - move a task from a remote runqueue to the local runqueue.
* Both runqueues must be locked.
*/
@@ -3617,7 +3689,7 @@ unsigned long __weak arch_scale_freq_pow
unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
{
- unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long weight = sd->span_weight;
unsigned long smt_gain = sd->smt_gain;
smt_gain /= weight;
@@ -3650,7 +3722,7 @@ unsigned long scale_rt_power(int cpu)
static void update_cpu_power(struct sched_domain *sd, int cpu)
{
- unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long weight = sd->span_weight;
unsigned long power = SCHED_LOAD_SCALE;
struct sched_group *sdg = sd->groups;
@@ -5149,21 +5221,9 @@ void account_idle_time(cputime_t cputime
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
cputime64_t cputime64 = cputime_to_cputime64(cputime);
struct rq *rq = this_rq();
- struct task_struct *task;
- if (atomic_read(&rq->nr_iowait) > 0) {
- for (task = current; task != &init_task; task = task->parent)
- ;
- /* task now points to init */
- for_each_process(task) {
- /* this pointlessly prints the name and PID of each task */
- if (task->in_iowait) {
- task->iowait = cputime64_add(task->iowait, cputime64);
- //printk("%s[%d]\n", task->comm, task->pid);
- }
- }
+ if (atomic_read(&rq->nr_iowait) > 0)
cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
- }
else
cpustat->idle = cputime64_add(cpustat->idle, cputime64);
}
@@ -5223,45 +5283,90 @@ cputime_t task_stime(struct task_struct
{
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
+# define nsecs_to_cputime(__nsecs) \
+ msecs_to_cputime(div_u64((__nsecs), NSEC_PER_MSEC))
+#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);
+ cputime_t utime = p->utime, total = utime + p->stime;
u64 temp;
/*
* Use CFS's precise accounting:
*/
- temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
+ temp = (u64)nsecs_to_cputime(p->se.sum_exec_runtime);
if (total) {
temp *= utime;
do_div(temp, total);
}
- utime = (clock_t)temp;
+ utime = (cputime_t)temp;
- p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
+ p->prev_utime = max(p->prev_utime, utime);
return p->prev_utime;
}
cputime_t task_stime(struct task_struct *p)
{
- clock_t stime;
+ cputime_t stime;
/*
* Use CFS's precise accounting. (we subtract utime from
* the total, to make sure the total observed by userspace
* grows monotonically - apps rely on that):
*/
- stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
- cputime_to_clock_t(task_utime(p));
+ stime = nsecs_to_cputime(p->se.sum_exec_runtime) - task_utime(p);
if (stime >= 0)
- p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
+ p->prev_stime = max(p->prev_stime, 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 = rtime;
+
+ temp *= 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)
@@ -5553,7 +5658,7 @@ int mutex_spin_on_owner(struct mutex *lo
* the mutex owner just released it and exited.
*/
if (probe_kernel_address(&owner->cpu, cpu))
- goto out;
+ return 0;
#else
cpu = owner->cpu;
#endif
@@ -5563,14 +5668,14 @@ int mutex_spin_on_owner(struct mutex *lo
* the cpu field may no longer be valid.
*/
if (cpu >= nr_cpumask_bits)
- goto out;
+ return 0;
/*
* We need to validate that we can do a
* get_cpu() and that we have the percpu area.
*/
if (!cpu_online(cpu))
- goto out;
+ return 0;
rq = cpu_rq(cpu);
@@ -5589,7 +5694,7 @@ int mutex_spin_on_owner(struct mutex *lo
cpu_relax();
}
-out:
+
return 1;
}
#endif
@@ -5937,14 +6042,15 @@ EXPORT_SYMBOL(wait_for_completion_killab
*/
bool try_wait_for_completion(struct completion *x)
{
+ unsigned long flags;
int ret = 1;
- spin_lock_irq(&x->wait.lock);
+ spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
- spin_unlock_irq(&x->wait.lock);
+ spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
@@ -5959,12 +6065,13 @@ EXPORT_SYMBOL(try_wait_for_completion);
*/
bool completion_done(struct completion *x)
{
+ unsigned long flags;
int ret = 1;
- spin_lock_irq(&x->wait.lock);
+ spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
- spin_unlock_irq(&x->wait.lock);
+ spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(completion_done);
@@ -6058,7 +6165,7 @@ void rt_mutex_setprio(struct task_struct
if (running)
p->sched_class->set_curr_task(rq);
if (on_rq) {
- enqueue_task(rq, p, 0);
+ enqueue_task(rq, p, 0, oldprio < prio);
check_class_changed(rq, p, prev_class, oldprio, running);
}
@@ -6102,7 +6209,7 @@ void set_user_nice(struct task_struct *p
delta = p->prio - old_prio;
if (on_rq) {
- enqueue_task(rq, p, 0);
+ enqueue_task(rq, p, 0, false);
/*
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
@@ -6493,7 +6600,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_
return -EINVAL;
retval = -ESRCH;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_process_by_pid(pid);
if (p) {
retval = security_task_getscheduler(p);
@@ -6501,7 +6608,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_
retval = p->policy
| (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
}
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return retval;
}
@@ -6519,7 +6626,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, p
if (!param || pid < 0)
return -EINVAL;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_process_by_pid(pid);
retval = -ESRCH;
if (!p)
@@ -6530,7 +6637,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, p
goto out_unlock;
lp.sched_priority = p->rt_priority;
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
/*
* This one might sleep, we cannot do it with a spinlock held ...
@@ -6540,7 +6647,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, p
return retval;
out_unlock:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return retval;
}
@@ -6551,22 +6658,18 @@ long sched_setaffinity(pid_t pid, const
int retval;
get_online_cpus();
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_process_by_pid(pid);
if (!p) {
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
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.
- */
+ /* Prevent p going away */
get_task_struct(p);
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
retval = -ENOMEM;
@@ -6647,10 +6750,12 @@ SYSCALL_DEFINE3(sched_setaffinity, pid_t
long sched_getaffinity(pid_t pid, struct cpumask *mask)
{
struct task_struct *p;
+ unsigned long flags;
+ struct rq *rq;
int retval;
get_online_cpus();
- read_lock(&tasklist_lock);
+ rcu_read_lock();
retval = -ESRCH;
p = find_process_by_pid(pid);
@@ -6661,10 +6766,12 @@ long sched_getaffinity(pid_t pid, struct
if (retval)
goto out_unlock;
+ rq = task_rq_lock(p, &flags);
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+ task_rq_unlock(rq, &flags);
out_unlock:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
put_online_cpus();
return retval;
@@ -6903,6 +7010,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, p
{
struct task_struct *p;
unsigned int time_slice;
+ unsigned long flags;
+ struct rq *rq;
int retval;
struct timespec t;
@@ -6910,7 +7019,7 @@ SYSCALL_DEFINE2(sched_rr_get_interval, p
return -EINVAL;
retval = -ESRCH;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_process_by_pid(pid);
if (!p)
goto out_unlock;
@@ -6919,15 +7028,17 @@ SYSCALL_DEFINE2(sched_rr_get_interval, p
if (retval)
goto out_unlock;
- time_slice = p->sched_class->get_rr_interval(p);
+ rq = task_rq_lock(p, &flags);
+ time_slice = p->sched_class->get_rr_interval(rq, p);
+ task_rq_unlock(rq, &flags);
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
jiffies_to_timespec(time_slice, &t);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
return retval;
out_unlock:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return retval;
}
@@ -6939,7 +7050,7 @@ void sched_show_task(struct task_struct
unsigned state;
state = p->state ? __ffs(p->state) + 1 : 0;
- printk(KERN_INFO "%-15.15s %c", p->comm,
+ 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)
@@ -7018,6 +7129,7 @@ void __cpuinit init_idle(struct task_str
spin_lock_irqsave(&rq->lock, flags);
__sched_fork(idle);
+ idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
@@ -7112,7 +7224,19 @@ int set_cpus_allowed_ptr(struct task_str
struct rq *rq;
int ret = 0;
+ /*
+ * Serialize against TASK_WAKING so that ttwu() and wunt() can
+ * drop the rq->lock and still rely on ->cpus_allowed.
+ */
+again:
+ while (task_is_waking(p))
+ cpu_relax();
rq = task_rq_lock(p, &flags);
+ if (task_is_waking(p)) {
+ task_rq_unlock(rq, &flags);
+ goto again;
+ }
+
if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL;
goto out;
@@ -7141,7 +7265,7 @@ int set_cpus_allowed_ptr(struct task_str
get_task_struct(mt);
task_rq_unlock(rq, &flags);
- wake_up_process(rq->migration_thread);
+ wake_up_process(mt);
put_task_struct(mt);
wait_for_completion(&req.done);
tlb_migrate_finish(p->mm);
@@ -7168,7 +7292,7 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
{
struct rq *rq_dest, *rq_src;
- int ret = 0, on_rq;
+ int ret = 0;
if (unlikely(!cpu_active(dest_cpu)))
return ret;
@@ -7180,19 +7304,17 @@ static int __migrate_task(struct task_st
/* Already moved. */
if (task_cpu(p) != src_cpu)
goto done;
- /* Waking up, don't get in the way of try_to_wake_up(). */
- if (p->state == TASK_WAKING)
- goto fail;
/* Affinity changed (again). */
if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
goto fail;
- on_rq = p->se.on_rq;
- if (on_rq)
+ /*
+ * If we're not on a rq, the next wake-up will ensure we're
+ * placed properly.
+ */
+ if (p->se.on_rq) {
deactivate_task(rq_src, p, 0);
-
- set_task_cpu(p, dest_cpu);
- if (on_rq) {
+ set_task_cpu(p, dest_cpu);
activate_task(rq_dest, p, 0);
check_preempt_curr(rq_dest, p, 0);
}
@@ -7271,57 +7393,29 @@ static int migration_thread(void *data)
}
#ifdef CONFIG_HOTPLUG_CPU
-
-static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
-{
- int ret;
-
- local_irq_disable();
- ret = __migrate_task(p, src_cpu, dest_cpu);
- local_irq_enable();
- return ret;
-}
-
/*
* Figure out where task on dead CPU should go, use force if necessary.
*/
-static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
+void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
{
- int dest_cpu;
- const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu));
-
-again:
- /* Look for allowed, online CPU in same node. */
- for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
- if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
- goto move;
-
- /* Any allowed, online CPU? */
- dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
- if (dest_cpu < nr_cpu_ids)
- goto move;
-
- /* No more Mr. Nice Guy. */
- if (dest_cpu >= nr_cpu_ids) {
- cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
- dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
+ struct rq *rq = cpu_rq(dead_cpu);
+ int needs_cpu, uninitialized_var(dest_cpu);
+ unsigned long flags;
- /*
- * Don't tell them about moving exiting tasks or
- * kernel threads (both mm NULL), since they never
- * leave kernel.
- */
- if (p->mm && printk_ratelimit()) {
- printk(KERN_INFO "process %d (%s) no "
- "longer affine to cpu%d\n",
- task_pid_nr(p), p->comm, dead_cpu);
- }
- }
+ local_irq_save(flags);
-move:
- /* It can have affinity changed while we were choosing. */
- if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu)))
- goto again;
+ spin_lock(&rq->lock);
+ needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING);
+ if (needs_cpu)
+ dest_cpu = select_fallback_rq(dead_cpu, p);
+ spin_unlock(&rq->lock);
+ /*
+ * It can only fail if we race with set_cpus_allowed(),
+ * in the racer should migrate the task anyway.
+ */
+ if (needs_cpu)
+ __migrate_task(p, dead_cpu, dest_cpu);
+ local_irq_restore(flags);
}
/*
@@ -7669,10 +7763,9 @@ migration_call(struct notifier_block *nf
unsigned long flags;
struct rq *rq;
- switch (action) {
+ switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
p = kthread_create(migration_thread, hcpu, "migration/%d", cpu);
if (IS_ERR(p))
return NOTIFY_BAD;
@@ -7687,7 +7780,6 @@ migration_call(struct notifier_block *nf
break;
case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
/* Strictly unnecessary, as first user will wake it. */
wake_up_process(cpu_rq(cpu)->migration_thread);
@@ -7704,7 +7796,6 @@ migration_call(struct notifier_block *nf
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
if (!cpu_rq(cpu)->migration_thread)
break;
/* Unbind it from offline cpu so it can run. Fall thru. */
@@ -7715,14 +7806,22 @@ migration_call(struct notifier_block *nf
cpu_rq(cpu)->migration_thread = NULL;
break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
- migrate_live_tasks(cpu);
+ case CPU_POST_DEAD:
+ /*
+ * Bring the migration thread down in CPU_POST_DEAD event,
+ * since the timers should have got migrated by now and thus
+ * we should not see a deadlock between trying to kill the
+ * migration thread and the sched_rt_period_timer.
+ */
rq = cpu_rq(cpu);
kthread_stop(rq->migration_thread);
put_task_struct(rq->migration_thread);
rq->migration_thread = NULL;
+ break;
+
+ case CPU_DEAD:
+ migrate_live_tasks(cpu);
+ rq = cpu_rq(cpu);
/* Idle task back to normal (off runqueue, low prio) */
spin_lock_irq(&rq->lock);
update_rq_clock(rq);
@@ -7731,7 +7830,6 @@ migration_call(struct notifier_block *nf
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
spin_unlock_irq(&rq->lock);
- cpuset_unlock();
migrate_nr_uninterruptible(rq);
BUG_ON(rq->nr_running != 0);
calc_global_load_remove(rq);
@@ -7755,7 +7853,6 @@ migration_call(struct notifier_block *nf
break;
case CPU_DYING:
- case CPU_DYING_FROZEN:
/* Update our root-domain */
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
@@ -8075,6 +8172,9 @@ cpu_attach_domain(struct sched_domain *s
struct rq *rq = cpu_rq(cpu);
struct sched_domain *tmp;
+ for (tmp = sd; tmp; tmp = tmp->parent)
+ tmp->span_weight = cpumask_weight(sched_domain_span(tmp));
+
/* Remove the sched domains which do not contribute to scheduling. */
for (tmp = sd; tmp; ) {
struct sched_domain *parent = tmp->parent;
@@ -9499,6 +9599,8 @@ void __init sched_init(void)
init_task_group.parent = &root_task_group;
list_add(&init_task_group.siblings, &root_task_group.children);
#endif /* CONFIG_USER_SCHED */
+
+ autogroup_init(&init_task);
#endif /* CONFIG_GROUP_SCHED */
#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
@@ -9656,24 +9758,13 @@ static inline int preempt_count_equals(i
return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
}
-static int __might_sleep_init_called;
-int __init __might_sleep_init(void)
-{
- __might_sleep_init_called = 1;
- return 0;
-}
-early_initcall(__might_sleep_init);
-
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()) ||
- oops_in_progress)
- return;
- if (system_state != SYSTEM_RUNNING &&
- (!__might_sleep_init_called || system_state != SYSTEM_BOOTING))
+ system_state != SYSTEM_RUNNING || oops_in_progress)
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
@@ -10049,15 +10140,11 @@ void sched_destroy_group(struct task_gro
/* change task's runqueue when it moves between groups.
* The caller of this function should have put the task in its new group
* by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
- * reflect its new group.
+ * reflect its new group. Called with the runqueue lock held.
*/
-void sched_move_task(struct task_struct *tsk)
+void __sched_move_task(struct task_struct *tsk, struct rq *rq)
{
int on_rq, running;
- unsigned long flags;
- struct rq *rq;
-
- rq = task_rq_lock(tsk, &flags);
update_rq_clock(rq);
@@ -10073,13 +10160,22 @@ void sched_move_task(struct task_struct
#ifdef CONFIG_FAIR_GROUP_SCHED
if (tsk->sched_class->moved_group)
- tsk->sched_class->moved_group(tsk);
+ tsk->sched_class->moved_group(tsk, on_rq);
#endif
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (on_rq)
- enqueue_task(rq, tsk, 0);
+ enqueue_task(rq, tsk, 0, false);
+}
+
+void sched_move_task(struct task_struct *tsk)
+{
+ struct rq *rq;
+ unsigned long flags;
+
+ rq = task_rq_lock(tsk, &flags);
+ __sched_move_task(tsk, rq);
task_rq_unlock(rq, &flags);
}
@@ -10493,15 +10589,6 @@ cpu_cgroup_destroy(struct cgroup_subsys
static int
cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
- if ((current != tsk) && (!capable(CAP_SYS_NICE))) {
- const struct cred *cred = current_cred(), *tcred;
-
- tcred = __task_cred(tsk);
-
- if (cred->euid != tcred->uid && cred->euid != tcred->suid)
- return -EPERM;
- }
-
#ifdef CONFIG_RT_GROUP_SCHED
if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
return -EINVAL;
@@ -10860,12 +10947,30 @@ static void cpuacct_charge(struct task_s
}
/*
+ * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large
+ * in cputime_t units. As a result, cpuacct_update_stats calls
+ * percpu_counter_add with values large enough to always overflow the
+ * per cpu batch limit causing bad SMP scalability.
+ *
+ * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we
+ * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled
+ * and enabled. We cap it at INT_MAX which is the largest allowed batch value.
+ */
+#ifdef CONFIG_SMP
+#define CPUACCT_BATCH \
+ min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX)
+#else
+#define CPUACCT_BATCH 0
+#endif
+
+/*
* Charge the system/user time to the task's accounting group.
*/
static void cpuacct_update_stats(struct task_struct *tsk,
enum cpuacct_stat_index idx, cputime_t val)
{
struct cpuacct *ca;
+ int batch = CPUACCT_BATCH;
if (unlikely(!cpuacct_subsys.active))
return;
@@ -10874,7 +10979,7 @@ static void cpuacct_update_stats(struct
ca = task_ca(tsk);
do {
- percpu_counter_add(&ca->cpustat[idx], val);
+ __percpu_counter_add(&ca->cpustat[idx], val, batch);
ca = ca->parent;
} while (ca);
rcu_read_unlock();
@@ -10998,3 +11103,4 @@ void synchronize_sched_expedited(void)
EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
#endif /* #else #ifndef CONFIG_SMP */
+#endif /* CONFIG_SCHED_BFS */
projects / ziggy471-frankenstein-kernel.git / blobdiff