select: use freezable blocking call
authorColin Cross <ccross@android.com>
Mon, 6 May 2013 23:50:17 +0000 (23:50 +0000)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Sun, 12 May 2013 12:16:22 +0000 (14:16 +0200)
Avoid waking up every thread sleeping in a select 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>
fs/select.c

index 8c1c96c27062a504bfc151f33d335fcd8f6779b5..6b14dc7df3a46df3293da538abc2d65b3b67f94f 100644 (file)
@@ -27,6 +27,7 @@
 #include <linux/rcupdate.h>
 #include <linux/hrtimer.h>
 #include <linux/sched/rt.h>
+#include <linux/freezer.h>
 
 #include <asm/uaccess.h>
 
@@ -236,7 +237,8 @@ int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
 
        set_current_state(state);
        if (!pwq->triggered)
-               rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
+               rc = freezable_schedule_hrtimeout_range(expires, slack,
+                                                       HRTIMER_MODE_ABS);
        __set_current_state(TASK_RUNNING);
 
        /*