timers/core: Correct callback order during CPU hot plug
authorRichard Cochran <rcochran@linutronix.de>
Wed, 27 Jul 2016 09:08:18 +0000 (11:08 +0200)
committerIngo Molnar <mingo@kernel.org>
Thu, 28 Jul 2016 16:56:22 +0000 (18:56 +0200)
commit4fae16dffb812f0e0d98a0b2b0856ca48ca63e6c
treec661ae0eaa75eb0f4af66870bb0c34a5b1c4c273
parentcd894f149732a06ba4b2ccdc4cb86edf7ff68620
timers/core: Correct callback order during CPU hot plug

On the tear-down path, the dead CPU callback for the timers was
misplaced within the 'cpuhp_state' enumeration.  There is a hidden
dependency between the timers and block multiqueue.  The timers
callback must happen before the block multiqueue callback otherwise a
RCU stall occurs.

Move the timers callback to the proper place in the state machine.

Reported-and-tested-by: Jon Hunter <jonathanh@nvidia.com>
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 24f73b99716a ("timers/core: Convert to hotplug state machine")
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: John Stultz <john.stultz@linaro.org>
Cc: rt@linutronix.de
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1469610498-25914-1-git-send-email-rcochran@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
include/linux/cpuhotplug.h
kernel/cpu.c