--- kernel/cpu.c
+++ kernel/cpu.c
@@ -151,7 +151,7 @@ static inline void check_for_tasks(int c
write_lock_irq(&tasklist_lock);
for_each_process(p) {
- if (task_cpu(p) == cpu &&
+ if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
(!cputime_eq(p->utime, cputime_zero) ||
!cputime_eq(p->stime, cputime_zero)))
printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\
@@ -163,6 +163,7 @@ static inline void check_for_tasks(int c
}
struct take_cpu_down_param {
+ struct task_struct *caller;
unsigned long mod;
void *hcpu;
};
@@ -171,6 +172,7 @@ struct take_cpu_down_param {
static int __ref take_cpu_down(void *_param)
{
struct take_cpu_down_param *param = _param;
+ unsigned int cpu = (unsigned long)param->hcpu;
int err;
/* Ensure this CPU doesn't handle any more interrupts. */
@@ -181,6 +183,8 @@ static int __ref take_cpu_down(void *_pa
raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
param->hcpu);
+ if (task_cpu(param->caller) == cpu)
+ move_task_off_dead_cpu(cpu, param->caller);
/* Force idle task to run as soon as we yield: it should
immediately notice cpu is offline and die quickly. */
sched_idle_next();
@@ -191,10 +195,10 @@ static int __ref take_cpu_down(void *_pa
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- cpumask_var_t old_allowed;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
+ .caller = current,
.mod = mod,
.hcpu = hcpu,
};
@@ -205,10 +209,8 @@ static int __ref _cpu_down(unsigned int
if (!cpu_online(cpu))
return -EINVAL;
- if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL))
- return -ENOMEM;
-
cpu_hotplug_begin();
+ set_cpu_active(cpu, false);
err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
hcpu, -1, &nr_calls);
if (err == NOTIFY_BAD) {
@@ -223,10 +225,6 @@ static int __ref _cpu_down(unsigned int
goto out_release;
}
- /* Ensure that we are not runnable on dying cpu */
- cpumask_copy(old_allowed, ¤t->cpus_allowed);
- set_cpus_allowed_ptr(current, cpu_active_mask);
-
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
set_cpu_active(cpu, true);
@@ -235,7 +233,7 @@ static int __ref _cpu_down(unsigned int
hcpu) == NOTIFY_BAD)
BUG();
- goto out_allowed;
+ goto out_release;
}
BUG_ON(cpu_online(cpu));
@@ -253,8 +251,6 @@ static int __ref _cpu_down(unsigned int
check_for_tasks(cpu);
-out_allowed:
- set_cpus_allowed_ptr(current, old_allowed);
out_release:
cpu_hotplug_done();
if (!err) {
@@ -262,7 +258,6 @@ out_release:
hcpu) == NOTIFY_BAD)
BUG();
}
- free_cpumask_var(old_allowed);
return err;
}
@@ -280,18 +275,6 @@ int __ref cpu_down(unsigned int cpu)
goto out;
}
- set_cpu_active(cpu, false);
-
- /*
- * Make sure the all cpus did the reschedule and are not
- * using stale version of the cpu_active_mask.
- * This is not strictly necessary becuase stop_machine()
- * that we run down the line already provides the required
- * synchronization. But it's really a side effect and we do not
- * want to depend on the innards of the stop_machine here.
- */
- synchronize_sched();
-
err = _cpu_down(cpu, 0);
out:
@@ -382,19 +365,12 @@ int disable_nonboot_cpus(void)
return error;
cpu_maps_update_begin();
first_cpu = cpumask_first(cpu_online_mask);
- /* We take down all of the non-boot CPUs in one shot to avoid races
+ /*
+ * We take down all of the non-boot CPUs in one shot to avoid races
* with the userspace trying to use the CPU hotplug at the same time
*/
cpumask_clear(frozen_cpus);
- for_each_online_cpu(cpu) {
- if (cpu == first_cpu)
- continue;
- set_cpu_active(cpu, false);
- }
-
- synchronize_sched();
-
printk("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
projects / ziggy471-frankenstein-kernel.git / blobdiff