[v3,11/16] epoll: use freezable blocking call

Commit Message

Colin Cross May 6, 2013, 11:50 p.m. UTC

Avoid waking up every thread sleeping in an epoll_wait 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 <[e-mail]>
Signed-off-by: Colin Cross <[e-mail]>
---
 fs/eventpoll.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 9fec183..65245e7 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -34,6 +34,7 @@ 
 #include <linux/mutex.h>
 #include <linux/anon_inodes.h>
 #include <linux/device.h>
+#include <linux/freezer.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <asm/mman.h>
@@ -1543,7 +1544,8 @@  fetch_events:
 			}
 
 			spin_unlock_irqrestore(&ep->lock, flags);
-			if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+			if (!freezable_schedule_hrtimeout_range(to, slack,
+								HRTIMER_MODE_ABS))
 				timed_out = 1;
 
 			spin_lock_irqsave(&ep->lock, flags);