Commit a2d5f1f5 authored May 06, 2013 by Colin Cross Committed by Rafael J. Wysocki May 12, 2013

sigtimedwait: use freezable blocking call



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@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent b0f8c44f

kernel/signal.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -2848,7 +2848,7 @@ int do_sigtimedwait(const sigset_t which, siginfo_t info,
	recalc_sigpending();		recalc_sigpending();
	spin_unlock_irq(&tsk->sighand->siglock);		spin_unlock_irq(&tsk->sighand->siglock);

	timeout = schedule_timeout_interruptible(timeout);		timeout = freezable_schedule_timeout_interruptible(timeout);

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