[PATCH v3 14/16] nanosleep: use freezable blocking call

From: Colin Cross
Date: Mon May 06 2013 - 19:51:49 EST


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@xxxxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
---
kernel/hrtimer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 14be27f..e036276 100644
--- 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>

@@ -1525,7 +1526,7 @@ 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;
--
1.8.2.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/