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author | Peter Zijlstra <peterz@infradead.org> | 2014-10-29 12:21:57 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2014-11-04 07:17:45 +0100 |
commit | 36df04bc5273a046f53b5e359febc1225f85aa7b (patch) | |
tree | dac2719884ca16c1c11b003be614ad0a1bb1fee0 /include/linux/wait.h | |
parent | cb6538e740d7543cd989128625cf8cac4b471e0a (diff) | |
download | linux-stable-36df04bc5273a046f53b5e359febc1225f85aa7b.tar.gz linux-stable-36df04bc5273a046f53b5e359febc1225f85aa7b.tar.bz2 linux-stable-36df04bc5273a046f53b5e359febc1225f85aa7b.zip |
sched/wait: Reimplement wait_event_freezable()
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>
Diffstat (limited to 'include/linux/wait.h')
-rw-r--r-- | include/linux/wait.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 0421775e0b9f..2232ed16635a 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -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; \ |