diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2010-03-15 10:10:23 +0100 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-01-06 18:07:50 -0500 |
| commit | 16a938245f932bd0ccda8262bae52eb783684749 (patch) | |
| tree | 53c2677f2c7ffe547898f90d9d48153f3ac9016c /include | |
| parent | e58c3ed611b189990521a1cd23a5576385b2b038 (diff) | |
sched: _cpu_down(): Don't play with current->cpus_allowed
commit 6a1bdc1b577ebcb65f6603c57f8347309bc4ab13 upstream.
_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.
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: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'include')
| -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 2b7b81df78b3..fbdbc26a31e1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1846,6 +1846,7 @@ 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) {} |