From: "David Hildenbrand (Red Hat)" <david@kernel.org>
To: Shivank Garg <shivankg@amd.com>,
Andrew Morton <akpm@linux-foundation.org>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Nico Pache <npache@redhat.com>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Masami Hiramatsu <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-trace-kernel@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Zach O'Keefe <zokeefe@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Stephen Rothwell <sfr@canb.auug.org.au>,
Branden Moore <Branden.Moore@amd.com>
Subject: Re: [PATCH V5 2/2] mm/khugepaged: retry with sync writeback for MADV_COLLAPSE
Date: Mon, 19 Jan 2026 11:08:05 +0100 [thread overview]
Message-ID: <df4ca339-15aa-4346-bd66-00dc6002b630@kernel.org> (raw)
In-Reply-To: <20260118190939.8986-7-shivankg@amd.com>
On 1/18/26 20:09, Shivank Garg wrote:
> When MADV_COLLAPSE is called on file-backed mappings (e.g., executable
> text sections), the pages may still be dirty from recent writes.
> collapse_file() will trigger async writeback and fail with
> SCAN_PAGE_DIRTY_OR_WRITEBACK (-EAGAIN).
>
> MADV_COLLAPSE is a synchronous operation where userspace expects
> immediate results. If the collapse fails due to dirty pages, perform
> synchronous writeback on the specific range and retry once.
>
> This avoids spurious failures for freshly written executables while
> avoiding unnecessary synchronous I/O for mappings that are already clean.
>
> Reported-by: Branden Moore <Branden.Moore@amd.com>
> Closes: https://lore.kernel.org/all/4e26fe5e-7374-467c-a333-9dd48f85d7cc@amd.com
> Fixes: 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE")
> Suggested-by: David Hildenbrand <david@kernel.org>
> Tested-by: Lance Yang <lance.yang@linux.dev>
> Signed-off-by: Shivank Garg <shivankg@amd.com>
> ---
Looks good to me now, thanks Shivank!
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
--
Cheers
David
next prev parent reply other threads:[~2026-01-19 10:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-18 19:09 [PATCH V5 0/2] mm/khugepaged: fix dirty page handling " Shivank Garg
2026-01-18 19:09 ` [PATCH V5 1/2] mm/khugepaged: map dirty/writeback pages failures to EAGAIN Shivank Garg
2026-01-18 19:09 ` [PATCH V5 2/2] mm/khugepaged: retry with sync writeback for MADV_COLLAPSE Shivank Garg
2026-01-19 10:08 ` David Hildenbrand (Red Hat) [this message]
2026-01-22 11:07 ` Dev Jain
2026-01-22 22:34 ` David Hildenbrand (Red Hat)
2026-01-18 20:22 ` [PATCH V5 0/2] mm/khugepaged: fix dirty page handling " Andrew Morton
2026-01-19 5:07 ` Garg, Shivank
2026-01-19 9:58 ` David Hildenbrand (Red Hat)
2026-01-19 10:54 ` Lorenzo Stoakes
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=df4ca339-15aa-4346-bd66-00dc6002b630@kernel.org \
--to=david@kernel.org \
--cc=Branden.Moore@amd.com \
--cc=Liam.Howlett@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=baohua@kernel.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=dev.jain@arm.com \
--cc=lance.yang@linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=lorenzo.stoakes@oracle.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=npache@redhat.com \
--cc=rostedt@goodmis.org \
--cc=ryan.roberts@arm.com \
--cc=sfr@canb.auug.org.au \
--cc=shivankg@amd.com \
--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