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sched/wait: Reimplement wait_event_freezable()

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Provide better implementations of wait_event_freezable() APIs.

The problem is with freezer_do_not_count(), it hides the thread from
the freezer, even though this thread might not actually freeze/sleep
at all.

Cc: oleg@redhat.com
Cc: Rafael Wysocki <rjw@rjwysocki.net>

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-d86fz1jmso9wjxa8jfpinp8o@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra
2014-10-29 12:21:57 +01:00
committed by Ingo Molnar
parent cb6538e740
commit 36df04bc52
2 changed files with 57 additions and 38 deletions
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57
include/linux/wait.h
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@@ -267,6 +267,31 @@ do { \
__wait_event(wq, condition); \
} while (0)
#define __wait_event_freezable(wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
schedule(); try_to_freeze())
/**
* wait_event - sleep (or freeze) until a condition gets true
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
*
* The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
* to system load) until the @condition evaluates to true. The
* @condition is checked each time the waitqueue @wq is woken up.
*
* wake_up() has to be called after changing any variable that could
* change the result of the wait condition.
*/
#define wait_event_freezable(wq, condition) \
({ \
int __ret = 0; \
might_sleep(); \
if (!(condition)) \
__ret = __wait_event_freezable(wq, condition); \
__ret; \
})
#define __wait_event_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_UNINTERRUPTIBLE, 0, timeout, \
@@ -300,6 +325,24 @@ do { \
__ret; \
})
#define __wait_event_freezable_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, timeout, \
__ret = schedule_timeout(__ret); try_to_freeze())
/*
* like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
* increasing load and is freezable.
*/
#define wait_event_freezable_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_freezable_timeout(wq, condition, timeout); \
__ret; \
})
#define __wait_event_cmd(wq, condition, cmd1, cmd2) \
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
cmd1; schedule(); cmd2)
@@ -480,6 +523,20 @@ do { \
})
#define __wait_event_freezable_exclusive(wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
schedule(); try_to_freeze())
#define wait_event_freezable_exclusive(wq, condition) \
({ \
int __ret = 0; \
might_sleep(); \
if (!(condition)) \
__ret = __wait_event_freezable_exclusive(wq, condition);\
__ret; \
})
#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
({ \
int __ret = 0; \