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select: use freezable blocking call
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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>
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Colin Cross authored and Rafael J. Wysocki committed May 12, 2013
1 parent 1c441e9 commit 9745cdb
Showing 1 changed file with 3 additions and 1 deletion.
4 changes: 3 additions & 1 deletion fs/select.c
Original file line number Diff line number Diff line change
Expand Up @@ -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>

Expand Down Expand Up @@ -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);

/*
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