Re: Backport d583d360a6 into 5.12 stable

On Tue, Jun 22, 2021 at 06:30:46PM +0200, Oleksandr Natalenko wrote:

Hello.

I'd like to nominate d583d360a6 ("psi: Fix psi state corruption when schedule() races with cgroup move") for 5.12 stable tree.

Recently, I've hit this:

kernel: psi: inconsistent task state! task=2667:clementine cpu=21 psi_flags=0 
clear=1 set=0

and after that PSI IO went crazy high. That seems to match the symptoms described in the commit message.

But this says it fixes 4117cebf1a9f ("psi: Optimize task switch inside shared cgroups") which did not show up until 5.13-rc1, so how are you hitting this issue?

Did you try this patch on 5.12.y and see that it solved your problem?

thanks,

greg k-h