From: Baolin Wang <baolin.wang@linux.alibaba.com>
To: "David Hildenbrand (Arm)" <david@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Zi Yan <ziy@nvidia.com>, Hugh Dickins <hughd@google.com>,
"Liam R. Howlett" <liam@infradead.org>,
Nico Pache <nico.pache@linux.dev>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Usama Arif <usama.arif@linux.dev>,
Kiryl Shutsemau <kas@kernel.org>,
Zach O'Keefe <zokeefe@google.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Chris Mason <mason@kernel.org>,
stable@vger.kernel.org
Subject: Re: [PATCH] mm/khugepaged: don't map folios that are not uptodate in MADV_COLLAPSE
Date: Fri, 6 Nov 2026 10:49:09 +0800 [thread overview]
Message-ID: <b3035814-fa08-4e85-b3fd-a254e5b0a825@linux.alibaba.com> (raw)
In-Reply-To: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org>
On 11/6/26 2:16 AM, David Hildenbrand (Arm) wrote:
> madvise(MADV_COLLAPSE) can map PMD-sized pagecache folios that are not
> uptodate. For example, shmem fallocate() can put such folios into the
> page cache.
>
> collapse_file() already refuses to proceed with folios that are not
> uptodate. Let's just do the same in try_collapse_pte_mapped_thp() and skip
> such folios, leaving handling to the page faults.
>
> Note that collapse_file() effectively clears shmem folios through
> shmem_get_folio(); let's keep this fix simple and simply let the page
> fault path deal with that.
>
> Fixes: 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE")
> Reported-by: Chris Mason <mason@kernel.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
> ---
Make sense to me.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
next prev parent reply other threads:[~2026-11-06 2:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-05 18:16 David Hildenbrand (Arm)
2026-11-05 19:34 ` Lorenzo Stoakes (ARM)
2026-11-05 19:58 ` Hugh Dickins
2026-11-05 20:09 ` Zi Yan
2026-11-05 21:24 ` Zach O'Keefe
2026-11-06 1:08 ` SJ Park
2026-11-06 2:49 ` Baolin Wang [this message]
2026-11-06 2:53 ` Lance Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b3035814-fa08-4e85-b3fd-a254e5b0a825@linux.alibaba.com \
--to=baolin.wang@linux.alibaba.com \
--cc=akpm@linux-foundation.org \
--cc=baohua@kernel.org \
--cc=david@kernel.org \
--cc=dev.jain@arm.com \
--cc=hughd@google.com \
--cc=kas@kernel.org \
--cc=lance.yang@linux.dev \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mason@kernel.org \
--cc=nico.pache@linux.dev \
--cc=ryan.roberts@arm.com \
--cc=stable@vger.kernel.org \
--cc=usama.arif@linux.dev \
--cc=ziy@nvidia.com \
--cc=zokeefe@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®