Re: Suspicious RCU usage in enable_drhd_fault_handling()

[Baolu Lu]

On 1/16/25 21:34, Breno Leitao wrote:
> On Tue, Oct 29, 2024 at 09:15:55AM +0800, Baolu Lu wrote:
> > On 2024/10/28 16:43, Ido Schimmel wrote:
> > > Hi,
> > >
> > > I have recently enabled CONFIG_RCU_EXPERT and CONFIG_PROVE_RCU_LIST in
> > > our debug configuration file and started observing the following splat
> > > [1] on one of our machines during boot. Searched the archives, but did
> > > not find a similar report.
> > >
> > > Not sure what is the right fix as I am not familiar with this code, but
> > > I can easily test patches.
> > Thanks for reporting this issue. I've been able to reproduce it locally
> > and will work on a fix. I'll let you know as soon as I have an update.
> Have you had a chance to look at this problem? I am still seeing it in
> 6.13-rc7.

Yes. I have spent some time on this, but I haven't yet figured out a
simple way to fix it.

I tried to add the rcu lock or use the dmar_global_lock instead, but
neither proved successful. Perhaps it's time to reconsider the locking
scheme for those lists.

Thanks,
baolu