sched/wait: Remove might_sleep() from wait_event_cmd()

Mikulas Patocka · Ingo Molnar · commit 3e87523897e1 · 2015-02-03T12:14:25.000+01:00
The patch e22b886 ("sched/wait: Add might_sleep() checks") introduced a bug in the raid5 subsystem. The function raid5_quiesce() (and resize_stripes()) uses the 'cmd' part to release and acquire a spinlock (so we call the sleep primitives in atomic context), and therefore we cannot do the might_sleep() check. Remove it. Fixes: e22b886 ("sched/wait: Add might_sleep() checks") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1502020935580.13510@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/wait.h b/include/linux/wait.h
@@ -363,7 +363,6 @@ do {									\
  */
 #define wait_event_cmd(wq, condition, cmd1, cmd2)			\
 do {									\
-	might_sleep();							\
 	if (condition)							\
 		break;							\
 	__wait_event_cmd(wq, condition, cmd1, cmd2);			\
