Re: v6.12-rc workqueue lockups

[John Garry]

On 23/10/2024 21:39, Jan Kara wrote:
> On Wed 23-10-24 11:19:24, John Garry wrote:
> > Hi All,
> >
> > I have been seeing lockups reliably occur on v6.12-rc1, 3, 4 and linus'
> > master branch:
> >
> > Message from syslogd@jgarry-atomic-write-exp-e4-8-instance-20231214-1221 at
> > Oct 22 09:07:15 ...
> >   kernel:watchdog: BUG: soft lockup - CPU#12 stuck for 26s! [khugepaged:154]
>
> BTW, can you please share logs which would contain full stacktraces that
> this softlockup reports produce? The attached dmesg is just from fresh
> boot...  Thanks!

thanks for getting back to me.

So I think that enabling /proc/sys/kernel/softlockup_all_cpu_backtrace 
is required there. Unfortunately my VM often just locks up without any 
sign of life.

But I'll continue to try. And I'll also try reverting that commit you 
mentioned.

Cheers,
John