From: Matthew Wilcox <willy@infradead.org>
To: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, cfijalkovich@google.com,
song@kernel.org, william.kucharski@oracle.com, hughd@google.com
Subject: Re: [PATCH v2 1/2] mm, thp: check page mapping when truncating page cache
Date: Wed, 22 Sep 2021 12:37:20 +0100 [thread overview]
Message-ID: <YUsVcEDcQ2vEzjGg@casper.infradead.org> (raw)
In-Reply-To: <20210922070645.47345-2-rongwei.wang@linux.alibaba.com>
On Wed, Sep 22, 2021 at 03:06:44PM +0800, Rongwei Wang wrote:
> Transparent huge page has supported read-only non-shmem files. The file-
> backed THP is collapsed by khugepaged and truncated when written (for
> shared libraries).
>
> However, there is race in two possible places.
>
> 1) multiple writers truncate the same page cache concurrently;
> 2) collapse_file rolls back when writer truncates the page cache;
As I've said before, the bug here is that somehow there is a writable fd
to a file with THPs. That's what we need to track down and fix.
https://lore.kernel.org/linux-mm/YUdL3lFLFHzC80Wt@casper.infradead.org/
next prev parent reply other threads:[~2021-09-22 11:38 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-06 12:11 [PATCH 0/2] mm, thp: fix file-backed THP race in collapse_file Rongwei Wang
2021-09-06 12:11 ` [PATCH 1/2] mm, thp: check page mapping when truncating page cache Rongwei Wang
2021-09-07 2:49 ` Yu Xu
2021-09-07 18:08 ` Yang Shi
2021-09-08 2:35 ` Rongwei Wang
2021-09-08 21:48 ` Yang Shi
2021-09-09 1:25 ` Rongwei Wang
2021-09-13 14:49 ` [mm, thp] 20753096b6: BUG:unable_to_handle_page_fault_for_address kernel test robot
2021-09-06 12:12 ` [PATCH 2/2] mm, thp: bail out early in collapse_file for writeback page Rongwei Wang
2021-09-07 16:56 ` Yang Shi
2021-09-08 2:16 ` Rongwei Wang
2021-09-08 21:51 ` Yang Shi
2021-09-09 1:33 ` Rongwei Wang
2021-09-22 7:06 ` [PATCH v2 0/2] mm, thp: fix file-backed THP race in collapse_file and truncate pagecache Rongwei Wang
2021-09-22 7:06 ` [PATCH v2 1/2] mm, thp: check page mapping when truncating page cache Rongwei Wang
2021-09-22 11:37 ` Matthew Wilcox [this message]
2021-09-22 17:04 ` Rongwei Wang
2021-09-24 2:43 ` Andrew Morton
2021-09-24 3:08 ` Yang Shi
2021-09-24 3:35 ` Rongwei Wang
2021-09-24 7:12 ` Rongwei Wang
2021-09-27 22:24 ` Song Liu
2021-09-28 12:06 ` Matthew Wilcox
2021-09-28 16:59 ` Song Liu
2021-09-28 16:20 ` Rongwei Wang
2021-09-29 7:14 ` Song Liu
2021-09-29 7:50 ` Rongwei Wang
2021-09-29 16:59 ` Song Liu
2021-09-29 17:55 ` Matthew Wilcox
2021-09-29 23:41 ` Song Liu
2021-09-30 0:00 ` Matthew Wilcox
2021-09-30 0:41 ` Song Liu
2021-09-30 2:14 ` Rongwei Wang
2021-10-04 17:26 ` Rongwei Wang
2021-10-04 19:05 ` Matthew Wilcox
2021-10-05 1:58 ` Rongwei Wang
2021-10-04 20:26 ` Song Liu
2021-10-05 2:58 ` Hugh Dickins
2021-10-05 3:07 ` Matthew Wilcox
2021-10-05 9:03 ` Rongwei Wang
2021-09-30 1:54 ` Rongwei Wang
2021-09-30 3:26 ` Song Liu
2021-09-30 5:24 ` Hugh Dickins
2021-09-30 15:28 ` Matthew Wilcox
2021-09-30 16:49 ` Hugh Dickins
2021-09-30 17:39 ` Yang Shi
2021-10-02 17:08 ` Matthew Wilcox
2021-10-04 18:28 ` Yang Shi
2021-10-04 19:31 ` Matthew Wilcox
2021-10-05 2:26 ` Hugh Dickins
2021-10-02 2:22 ` Rongwei Wang
2021-09-22 7:06 ` [PATCH v2 2/2] mm, thp: bail out early in collapse_file for writeback page Rongwei Wang
2021-10-06 2:18 ` [PATCH v3 v3 0/2] mm, thp: fix file-backed THP race in collapse_file and truncate pagecache Rongwei Wang
2021-10-06 2:18 ` [PATCH v3 v3 1/2] mm, thp: lock filemap when truncating page cache Rongwei Wang
2021-10-06 2:18 ` [PATCH v3 v3 2/2] mm, thp: bail out early in collapse_file for writeback page Rongwei Wang
2021-10-06 2:41 ` Matthew Wilcox
2021-10-06 8:39 ` Rongwei Wang
2021-10-06 17:58 ` Yang Shi
2021-10-11 2:22 ` [PATCH v4 0/2] mm, thp: fix file-backed THP race in collapse_file and truncate pagecache Rongwei Wang
2021-10-11 2:22 ` [PATCH v4 1/2] mm, thp: lock filemap when truncating page cache Rongwei Wang
2021-10-13 7:55 ` Rongwei Wang
2021-10-11 2:22 ` [PATCH v4 2/2] mm, thp: bail out early in collapse_file for writeback page Rongwei Wang
2021-10-11 3:08 ` Matthew Wilcox
2021-10-11 3:22 ` Rongwei Wang
2021-10-11 5:08 ` [PATCH v4 RESEND " Rongwei Wang
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=YUsVcEDcQ2vEzjGg@casper.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=cfijalkovich@google.com \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rongwei.wang@linux.alibaba.com \
--cc=song@kernel.org \
--cc=william.kucharski@oracle.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