diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-08-20 16:46:04 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-08-21 13:34:54 +0200 |
| commit | d82f0b0f6f1a0a25afc288fb7135b1601fe6df18 (patch) | |
| tree | 29991ab508ccfbacec6f6b2a7df714ee9d5c5fb5 /kernel/hrtimer.c | |
| parent | 6a55617ed5d1aa62b850de2cf66f5ede2eef4825 (diff) | |
migrate_timers: add comment, use spinlock_irq()
Add the comment to explain why the double lock in migrate_timers()
can't deadlock.
Change the code to use spinlock_irq() instead of local_irq_disable()
+ spin_lock().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/hrtimer.c')
| -rw-r--r-- | kernel/hrtimer.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index b8e4dce80a74..03ea1378c43b 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1620,9 +1620,11 @@ static void migrate_hrtimers(int cpu) new_base = &get_cpu_var(hrtimer_bases); tick_cancel_sched_timer(cpu); - - local_irq_disable(); - spin_lock(&new_base->lock); + /* + * The caller is globally serialized and nobody else + * takes two locks at once, deadlock is not possible. + */ + spin_lock_irq(&new_base->lock); spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { @@ -1631,8 +1633,7 @@ static void migrate_hrtimers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_enable(); + spin_unlock_irq(&new_base->lock); put_cpu_var(hrtimer_bases); } #endif /* CONFIG_HOTPLUG_CPU */ |