From 0c9af09262864a2744091ee94c98c4a8fd60c98b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 21 Nov 2011 12:32:24 -0800 Subject: 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 --- kernel/power/process.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/power') 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 { -- cgit v1.2.3