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| author | Oleg Nesterov <oleg@redhat.com> | 2010-03-15 10:10:23 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-07-20 19:11:47 +0200 |
| commit | bb8eef78087fd2f10bcfca68f794640f7d37592c (patch) | |
| tree | 360806301ba7f98b34178b8e89c958df1d3d535f /include/linux/sched.h | |
| parent | a325588ec5c7384514a79f01ddebf274477eaf51 (diff) | |
| download | lwn-bb8eef78087fd2f10bcfca68f794640f7d37592c.tar.gz lwn-bb8eef78087fd2f10bcfca68f794640f7d37592c.zip | |
sched: _cpu_down(): Don't play with current->cpus_allowed
_cpu_down() changes the current task's affinity and then recovers it at
the end. The problems are well known: we can't restore old_allowed if it
was bound to the now-dead-cpu, and we can race with the userspace which
can change cpu-affinity during unplug.
_cpu_down() should not play with current->cpus_allowed at all. Instead,
take_cpu_down() can migrate the caller of _cpu_down() after __cpu_disable()
removes the dying cpu from cpu_online_mask.
[ upstream commit: 6a1bdc1b577ebcb65f6603c57f8347309bc4ab13 ]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091023.GA9148@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 21947b587171..32c3f6cd4d7f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2036,6 +2036,7 @@ extern void sched_clock_idle_sleep_event(void); extern void sched_clock_idle_wakeup_event(u64 delta_ns); #ifdef CONFIG_HOTPLUG_CPU +extern void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p); extern void idle_task_exit(void); #else static inline void idle_task_exit(void) {} |