Re: [PATCH v2 1/4] mm/hwpoison: mf_mutex for soft offline and unpoison

[Naoya Horiguchi <naoya.horiguchi@linux.dev>]

On Tue, Oct 26, 2021 at 06:32:36PM -0700, Yang Shi wrote:
> On Mon, Oct 25, 2021 at 4:06 PM Naoya Horiguchi
> <naoya.horiguchi@linux.dev> wrote:
> >
> > From: Naoya Horiguchi <naoya.horiguchi@nec.com>
> >
> > Originally mf_mutex is introduced to serialize multiple MCE events, but
> > it's also helpful to exclude races among  soft_offline_page() and
> > unpoison_memory().  So apply mf_mutex to them.
> 
> My understanding is it is not that useful to make unpoison run
> parallel with memory_failure() and soft offline, so they can be
> serialized by mf_mutex and we could make the memory failure handler
> and soft offline simpler.

Thank you for the suggestion, this sounds correct and more specific.

> 
> If the above statement is correct, could you please tweak this commit
> log to reflect it with patch #2 squashed into this patch?

Sure, I'm thinking of revising like below:

  Originally mf_mutex is introduced to serialize multiple MCE events, but
  it is not that useful to allow unpoison to run in parallel with memory_failure()
  and soft offline.  So apply mf_they to soft offline and unpoison.
  The memory failure handler and soft offline handler get simpler with this.

Thanks,
Naoya Horiguchi