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>

diff --git a/kernel/signal.c b/kernel/signal.c
index 113411bfe8b1205ad0f26556776f2a317e06eb0c..50e41075ac77105fd26d190b2068929af6c4becc 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2848,7 +2848,7 @@ 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);