UPSTREAM next (v3.11): nanosleep: use freezable blocking call
Colin Cross [Mon, 6 May 2013 23:50:19 +0000 (23:50 +0000)]
Avoid waking up every thread sleeping in a nanosleep 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>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit b0f8c44f30e58c3aaaaaf864d5c3d3cc2e8a4c2d)
Change-Id: Ib8dbab690b5adf33a8fe4194ae961ed7d58d3f26
Reviewed-on: http://git-master/r/228699
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

kernel/hrtimer.c

index 2288fbd..e268e26 100644 (file)
@@ -47,6 +47,7 @@
 #include <linux/sched/sysctl.h>
 #include <linux/sched/rt.h>
 #include <linux/timer.h>
+#include <linux/freezer.h>
 
 #include <asm/uaccess.h>
 
@@ -1543,7 +1544,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
                        t->task = NULL;
 
                if (likely(t->task))
-                       schedule();
+                       freezable_schedule();
 
                hrtimer_cancel(&t->timer);
                mode = HRTIMER_MODE_ABS;