[PATCH v3 15/16] sigtimedwait: use freezable blocking call

From: Colin Cross
Date: Mon May 06 2013 - 19:50:52 EST


Avoid waking up every thread sleeping in a sigtimedwait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
---
kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 598dc06..10a70a0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2845,7 +2845,7 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
recalc_sigpending();
spin_unlock_irq(&tsk->sighand->siglock);

- timeout = schedule_timeout_interruptible(timeout);
+ timeout = freezable_schedule_timeout_interruptible(timeout);

spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, &tsk->real_blocked);
--
1.8.2.1

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