[PATCH v2 06/10] select: use freezable blocking call

From: Colin Cross
Date: Wed May 01 2013 - 21:36:59 EST


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.

Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
---
fs/select.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/select.c b/fs/select.c
index 8c1c96c..6b14dc7 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -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);

/*
--
1.8.2.1

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