Re: [PATCH] cgroup/cpuset: Fix a race condition when reading cpuset.*

From: Qais Yousef
Date: Thu Feb 13 2020 - 09:36:45 EST


On 02/13/20 08:56, Tejun Heo wrote:
> Hello,
>
> On Thu, Feb 13, 2020 at 11:50:16AM +0000, Qais Yousef wrote:
> > I ran 500 iterations of cpuset_hotplug_test.sh on the branch, it passed.
> >
> > I also cherry-picked commit 6426bfb1d5f0 ("cpuset: Make cpuset hotplug synchronous")
> > into v5.6-rc1 and ran 100 iterations and it passed too.
>
> Awesome, thanks for verifying.
>
> > While investigating the problem, I could reproduce it all the way back to v5.0.
> > Stopped there so earlier versions could still have the problem.
> >
> > Do you think it's worth porting the change to stable trees? Admittedly the
> > problem should be benign, but it did trigger an LTP failure.
>
> I'm afraid not. It's not an issue which would affect actual use cases
> and there's (as always) some risks involved with backporting it, so
> the benefit just doesn't seem justifiable here.

Yeah I can't see how a real application would depend on this functionality
other than for informational reasons. Or testing like in this case.

Thanks

--
Qais Yousef