From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: <linux-fsdevel@vger.kernel.org>,
Andreas Dilger <adilger.kernel@dilger.ca>,
<linux-ext4@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ext4: add sysfs attr /sys/fs/ext4/<disk>/journal_task
Date: Thu, 21 Feb 2019 11:52:58 -0500 [thread overview]
Message-ID: <20190221165258.GE10245@mit.edu> (raw)
In-Reply-To: <154927546304.133377.2385004506198637025.stgit@buzz>
On Mon, Feb 04, 2019 at 01:17:43PM +0300, Konstantin Khlebnikov wrote:
> This is useful for moving journal thread into cgroup or
> for tracing it with ftrace/perf/blktrace.
>
> For now the only way is `pgrep jbd2/$DISK` but this is not reliable:
> name may be longer than "comm" limit and any task could mock it.
>
> Attribute shows pid in current pid-namespace or 0 if task is unreachable.
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Thanks, applied with one change; if the file system does not have a
journal, reading the /sys/fs/ext4/<disk>/journal_task will return
"<none>" instead of returning a ESRCH error.
- Ted
prev parent reply other threads:[~2019-02-21 16:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-04 10:17 [PATCH] ext4: add sysfs attr /sys/fs/ext4/<disk>/journal_task Konstantin Khlebnikov
2019-02-21 16:52 ` Theodore Y. Ts'o [this message]
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