2021-05-19 20:22:30

by Aaron Tomlin

[permalink] [raw]
Subject: Re: [PATCH v2] mm/page_alloc: bail out on fatal signal during reclaim/compaction retry attempt

On Wed 2021-05-19 20:32 +0100, Matthew Wilcox wrote:
> On Wed, May 19, 2021 at 08:23:21PM +0100, Aaron Tomlin wrote:
> > +++ b/mm/page_alloc.c
> > @@ -4252,6 +4252,9 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
> > if (!order)
> > return false;
> >
> > + if (fatal_signal_pending(current))
> > + goto out;
>
> I think 'goto out' will be confusing. It'll output a tracepoint, which
> isn't going to record that a fatal signal is pending, so it'll cause
> some head scratching for someone looking through the traces. I
> think we should just return false here and skip the tracepoint.

I agree. Having said this, I do plan to send a patch to illustrate why
compaction should not retry to avoid possible confusion. Nevertheless, I am
happy to modify as per your request.


Kind regards,

--
Aaron Tomlin