epoll: use freezable blocking call

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 <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/fs/eventpoll.c b/fs/eventpoll.c
index deecc72..0cff443 100644 (file)
--- 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>
@@ -1602,7 +1603,8 @@ 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);