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| author | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:24 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:24 -0800 |
| commit | 0c9af09262864a2744091ee94c98c4a8fd60c98b (patch) | |
| tree | e7dacbb7f370e0d7c515ed743a2c5b5179a1de5e /kernel/power/process.c | |
| parent | 6cd8dedcdd8e8de01391a7cf25f0b2afeb24f8f4 (diff) | |
| download | linux-0c9af09262864a2744091ee94c98c4a8fd60c98b.tar.bz2 | |
freezer: use dedicated lock instead of task_lock() + memory barrier
Freezer synchronization is needlessly complicated - it's by no means a
hot path and the priority is staying unintrusive and safe. This patch
makes it simply use a dedicated lock instead of piggy-backing on
task_lock() and playing with memory barriers.
On the failure path of try_to_freeze_tasks(), locking is moved from it
to cancel_freezing(). This makes the frozen() test racy but the race
here is a non-issue as the warning is printed for tasks which failed
to enter frozen for 20 seconds and race on PF_FROZEN at the last
moment doesn't change anything.
This simplifies freezer implementation and eases further changes
including some race fixes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/power/process.c')
| -rw-r--r-- | kernel/power/process.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c index 9db048fb0d70..bd420ca48261 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -118,11 +118,9 @@ static int try_to_freeze_tasks(bool sig_only) read_lock(&tasklist_lock); do_each_thread(g, p) { - task_lock(p); if (!wakeup && freezing(p) && !freezer_should_skip(p)) sched_show_task(p); cancel_freezing(p); - task_unlock(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); } else { |