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Message-ID: <8aafa00865f564d58dfa39a1e2816a8ec0eab097.camel@surriel.com>
Subject: Re: [PATCH] mm: clean up hwpoison page cache page in fault path
From:   Rik van Riel <riel@surriel.com>
To:     John Hubbard <jhubbard@nvidia.com>
Cc:     linux-kernel@vger.kernel.org, kernel-team@fb.com,
        linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Matthew Wilcox <willy@infradead.org>
Date:   Sun, 13 Feb 2022 14:21:26 -0500
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         <10f4319c-45fe-2a7b-db6f-2d5fe8ae98a0@nvidia.com>
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On Sun, 2022-02-13 at 00:56 -0800, John Hubbard wrote:
> On Fri, 11 Feb 2022, Rik van Riel wrote:
>=20
> > =C2=A0=C2=A0=C2=A0=20
> > This is particularly embarrassing when the page was offlined due to
> > having too many corrected memory errors. Now we are killing tasks
> > due to them trying to access memory that probably isn't even
> > corrupted.
>=20
> I'd recommend deleting that paragraph entirely. It's a separate
> question, and it is not necessarily an accurate assessment of that
> question either: the engineers who set the thresholds for "too many
> corrected errors" may not--in fact, probably *will not*--agree with
> your
> feeling that the memory is still working and reliable!

Fair enough. We try to offline pages before we get to
a point where the error correction might no longer be
able to correct the error correctly, but I am pretty
sure I have seen a few odd kernel crashes following a
stream of corrected errors that strongly suggested
corruption had in fact happened.

I'll take that paragraph out if anybody else asks
for further changes for v3 of the patch.

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