diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-08-20 23:46:04 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-08-21 11:34:54 (GMT) |
| commit | d82f0b0f6f1a0a25afc288fb7135b1601fe6df18 (patch) | |
| tree | 29991ab508ccfbacec6f6b2a7df714ee9d5c5fb5 /kernel/timer.c | |
| parent | 6a55617ed5d1aa62b850de2cf66f5ede2eef4825 (diff) | |
| download | linux-d82f0b0f6f1a0a25afc288fb7135b1601fe6df18.tar.xz | |
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/timer.c')
| -rw-r--r-- | kernel/timer.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index 03bc7f1..e8019cc 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1435,9 +1435,11 @@ static void __cpuinit migrate_timers(int cpu) BUG_ON(cpu_online(cpu)); old_base = per_cpu(tvec_bases, cpu); new_base = get_cpu_var(tvec_bases); - - 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); BUG_ON(old_base->running_timer); @@ -1452,8 +1454,7 @@ static void __cpuinit migrate_timers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_enable(); + spin_unlock_irq(&new_base->lock); put_cpu_var(tvec_bases); } #endif /* CONFIG_HOTPLUG_CPU */ |