sched/wait: Fix signal handling in bit wait helpers
authorPeter Zijlstra <peterz@infradead.org>
Tue, 1 Dec 2015 13:04:04 +0000 (14:04 +0100)
committerIngo Molnar <mingo@kernel.org>
Fri, 4 Dec 2015 09:10:15 +0000 (10:10 +0100)
commit68985633bccb6066bf1803e316fbc6c1f5b796d6
tree0756c924eb126f00b1a6c45db30ac6c0893c1327
parent89b411081d70fe3772efa4665279293269c1150d
sched/wait: Fix signal handling in bit wait helpers

Vladimir reported getting RCU stall warnings and bisected it back to
commit:

  743162013d40 ("sched: Remove proliferation of wait_on_bit() action functions")

That commit inadvertently reversed the calls to schedule() and signal_pending(),
thereby not handling the case where the signal receives while we sleep.

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mark.rutland@arm.com
Cc: neilb@suse.de
Cc: oleg@redhat.com
Fixes: 743162013d40 ("sched: Remove proliferation of wait_on_bit() action functions")
Fixes: cbbce8220949 ("SCHED: add some "wait..on_bit...timeout()" interfaces.")
Link: http://lkml.kernel.org/r/20151201130404.GL3816@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/wait.c