nanosleep: use freezable blocking call

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>

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index fd4b13b131f8db23fb17055caf5d33e23bec7b50..3ee4d06c6fc20bda08fa052a1c42d70c7d094cb8 100644 (file)
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -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>
 
@@ -1545,7 +1546,7 @@ 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;