Re: [PATCH V5 00/22] arch: Add basic LoongArch support

From: Xi Ruoyao
Date: Wed Jan 05 2022 - 12:22:15 EST


On Wed, 2022-01-05 at 19:51 +0800, Xi Ruoyao wrote:
> On Wed, 2022-01-05 at 17:40 +0800, Huacai Chen wrote:
> > Hi, Ruoyao,
> >
> > The problem still exists in 5.16-rc8, can you try to change
> > cpu_relax() definition to smp_mb()? It seems can fix the problem.
>
> Is there any workload which can triggers the panic?  I can't trigger it
> by building and testing GCC, or building the kernel anymore.
>
> And is your "stable" issue the same one I'd encountered?  To me changing
> barrier() to smp_mb() may fix some deadlock, but not a panic.  (I'm not
> an expert on CPU architecture or kernel programming, so maybe I'm wrong
> here.)
>
> I'll put my 3A5000 machine into a loop building kernel and see if I can
> trigger the panic again...

I can't reproduce the issue on 5.16-rc8. But I can reproduce it on
5.16-rc5 and the s/barrier/smp_mb/ change fixes the issue.

I'm still puzzled: if there some workload which can reproduce the issue
more deterministic?
--
Xi Ruoyao <xry111@xxxxxxxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University