Re: [PATCH v4] stop_machine: Disable preemption after queueing stopper threads

From: isaacm
Date: Tue Jul 17 2018 - 15:34:39 EST


Alright, we will make a new patch for this. Thanks for the feedback.

Thanks,
Isaac Manjarres
On 2018-07-17 11:34, Peter Zijlstra wrote:
On Tue, Jul 17, 2018 at 09:30:17AM -0700, Isaac J. Manjarres wrote:
After cpu_stop_queue_two_works() queues the cpu_stop works
for the stopper threads, it releases the locks held for
both threads, which enables preemption, which allows the
following race condition to occur:


Does not apply because an earlier version is already applied.

https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/kernel/stop_machine.c?id=9fb8d5dc4b649dd190e1af4ead670753e71bf907

if there still is a problem, please send a new patch that describes the
remaining problem.