Re: [PATCH] rcu: Enable runtime reset of the RCU stall panic count

[Cunlong Li <shenxiaogll@gmail.com>]

On Tue, Oct 06, 2026 at 05:27:51PM -0400, Joel Fernandes wrote:
> 
> 
> On 10/6/2026 9:17 AM, Cunlong Li wrote:
> >> It sounds like you do know that it is likely transient - but based on this description and the below, it sounds like you have not yet found a use of this patch.
> >>
> >>
> > To be precise, we worry that some of the stalls were transient, so a
> > panic reboot would affect the users.  But we have no hard evidence
> > either way: every incident ended in a forced reset, and the dmesg was
> > lost.  Going forward, we plan to enable the NMI and kdump to keep
> > investigating the cause of the RCU stalls. We will also monitor dmesg
> > to confirm whether transient RCU stalls actually occur.
> 
> 
> Right, I just worry that if you're not seeing recoverable/transient stalls and
> you start using this patch, then you might be causing side-effects that don't
> really help your problem and might be masking the real issue. It would be good
> to debug this further, and fix the right way IMO.
> 
> If you show that this patch indeed helps your problem, we can consider it for
> 7.5, but there's little bit of time. :-)

Hi Joel,

Understood, thanks.  We will keep monitoring dmesg for the root cause.
Once we observe self-recovering RCU stalls, we will resubmit the patch
with the evidence.

Thanks,
Cunlong

> 
> Thanks,
> 
> Joel Fernandes
> 
>