diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2014-04-09 12:50:34 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-04-18 12:07:22 +0200 |
| commit | 27e4f9d0012a9bb7011aade862f08679d2921ab0 (patch) | |
| tree | 93bc52db6aba1a6c11d4f72f8eab6ded443b5c99 /include/linux/wait.h | |
| parent | sched: Make scale_rt_power() deal with backward clocks (diff) | |
| download | linux-27e4f9d0012a9bb7011aade862f08679d2921ab0.tar.xz linux-27e4f9d0012a9bb7011aade862f08679d2921ab0.zip | |
sched/wait: Explain the shadowing and type inconsistencies
Stick in a comment before someone else tries to fix the sparse warning
this generates.
Requested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-o2ro6f3vkxklni0bc8f7m68s@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | include/linux/wait.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 559044c79232..2b563a15a77d 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -191,11 +191,23 @@ wait_queue_head_t *bit_waitqueue(void *, int); (!__builtin_constant_p(state) || \ state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ +/* + * The below macro ___wait_event() has an explicit shadow of the __ret + * variable when used from the wait_event_*() macros. + * + * This is so that both can use the ___wait_cond_timeout() construct + * to wrap the condition. + * + * The type inconsistency of the wait_event_*() __ret variable is also + * on purpose; we use long where we can return timeout values and int + * otherwise. + */ + #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ ({ \ __label__ __out; \ wait_queue_t __wait; \ - long __ret = ret; \ + long __ret = ret; /* explicit shadow */ \ \ INIT_LIST_HEAD(&__wait.task_list); \ if (exclusive) \ |