From: Andi Kleen <ak@linux.intel.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-mm@kvack.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Hugh Dickins <hughd@google.com>
Subject: Re: File THP and HWPoison
Date: Tue, 16 Mar 2021 09:36:49 -0700 [thread overview]
Message-ID: <20210316163649.GR203350@tassilo.jf.intel.com> (raw)
In-Reply-To: <20210316140947.GA3420@casper.infradead.org>
> So we now map the PMD-sized page into userspace, even though it has a
> HWPoison in it.
Yes that's bad. It might panic the system.
>
> I think there are two things that we should be doing:
>
> 1. Attempt to split THPs which are file-backed. That makes most of this
> problem disappear because there won't be THPs with HWPoison, mostly.
That seems simple and sensible.
> 2. When the THP fails to split, use a spare page flag to indicate that
> the THP contains a HWPoison bit in one of its subpages. There are a
> lot of PF_SECOND flags available for this purpose.
Why should it fail? I thought splitting always succeeds.
-Andi
next prev parent reply other threads:[~2021-03-16 16:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 14:09 File THP and HWPoison Matthew Wilcox
2021-03-16 16:36 ` Andi Kleen [this message]
2021-03-16 16:52 ` Matthew Wilcox
2021-03-18 14:08 ` Kirill A. Shutemov
2021-03-18 14:57 ` Matthew Wilcox
2021-03-18 17:25 ` HORIGUCHI NAOYA(堀口 直也)
2021-03-18 18:05 ` Yang Shi
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