Commit-ID: 27e4f9d0012a9bb7011aade862f08679d2921ab0 Gitweb: http://git.kernel.org/tip/27e4f9d0012a9bb7011aade862f08679d2921ab0 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Wed, 9 Apr 2014 12:50:34 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 18 Apr 2014 12:07:22 +0200
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 <a...@linux-foundation.org> Signed-off-by: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/n/tip-o2ro6f3vkxklni0bc8f7m...@git.kernel.org Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/wait.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/wait.h b/include/linux/wait.h index 559044c..2b563a1 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) \ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
