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From:   "Theodore Ts'o" <tytso@mit.edu>
To:     adilger.kernel@dilger.ca, hanjinke.666@bytedance.com
Cc:     "Theodore Ts'o" <tytso@mit.edu>, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, yi.zhang@huawei.com
Subject: Re: [PATCH v2] ext4: place buffer head allocation before handle start
Date:   Thu, 29 Sep 2022 23:19:35 -0400
Message-Id: <166450797714.256913.16618397949640055168.b4-ty@mit.edu>
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On Sat, 3 Sep 2022 09:24:29 +0800, Jinke Han wrote:
> From: Jinke Han <hanjinke.666@bytedance.com>
> 
> In our product environment, we encounter some jbd hung waiting handles to
> stop while several writters were doing memory reclaim for buffer head
> allocation in delay alloc write path. Ext4 do buffer head allocation with
> holding transaction handle which may be blocked too long if the reclaim
> works not so smooth. According to our bcc trace, the reclaim time in
> buffer head allocation can reach 258s and the jbd transaction commit also
> take almost the same time meanwhile. Except for these extreme cases,
> we often see several seconds delays for cgroup memory reclaim on our
> servers. This is more likely to happen considering docker environment.
> 
> [...]

Applied, thanks!

[1/1] ext4: place buffer head allocation before handle start
      commit: 843b6ee4b8d0d9e7507dad491920db1fbde12439

Best regards,
-- 
Theodore Ts'o <tytso@mit.edu>