All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jonathan Corbet <corbet@lwn.net>
To: Christian Brauner <brauner@kernel.org>, Tejun Heo <tj@kernel.org>,
	Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>,
	Zefan Li <lizefan.x@bytedance.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	cgroups@vger.kernel.org, containers@lists.linux.dev,
	Christian Brauner <christian.brauner@ubuntu.com>,
	Serge Hallyn <serge@hallyn.com>
Subject: Re: [PATCH v3 1/5] cgroup: introduce cgroup.kill
Date: Mon, 10 May 2021 09:39:02 -0600	[thread overview]
Message-ID: <874kfaha3t.fsf@meer.lwn.net> (raw)
In-Reply-To: <20210508121542.1269256-1-brauner@kernel.org>

Christian Brauner <brauner@kernel.org> writes:

> Introduce the cgroup.kill file. It does what it says on the tin and
> allows a caller to kill a cgroup by writing "1" into cgroup.kill.
> The file is available in non-root cgroups.

So I feel like I'm missing something fundamental here...perhaps somebody
can supply a suitable cluebat.  It seems inevitable to me that, sooner
or later, somebody will surely wish that this mechanism could send a
signal other than SIGKILL, but this interface won't allow that.  Even if
you won't want to implement an arbitrary signal now, it seems like
defining the interface to require writing "9" rather than "1" would
avoid closing that option off in the future.

I assume there's some reason why you don't want to do that, but I'm to
slow to figure out what it is...?

Thanks,

jon

WARNING: multiple messages have this Message-ID (diff)
From: Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>
To: Christian Brauner
	<brauner-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>
Cc: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Zefan Li <lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
	Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	containers-cunTk1MwBs/YUNznpcFYbw@public.gmane.org,
	Christian Brauner
	<christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>,
	Serge Hallyn <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH v3 1/5] cgroup: introduce cgroup.kill
Date: Mon, 10 May 2021 09:39:02 -0600	[thread overview]
Message-ID: <874kfaha3t.fsf@meer.lwn.net> (raw)
In-Reply-To: <20210508121542.1269256-1-brauner-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

Christian Brauner <brauner-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> writes:

> Introduce the cgroup.kill file. It does what it says on the tin and
> allows a caller to kill a cgroup by writing "1" into cgroup.kill.
> The file is available in non-root cgroups.

So I feel like I'm missing something fundamental here...perhaps somebody
can supply a suitable cluebat.  It seems inevitable to me that, sooner
or later, somebody will surely wish that this mechanism could send a
signal other than SIGKILL, but this interface won't allow that.  Even if
you won't want to implement an arbitrary signal now, it seems like
defining the interface to require writing "9" rather than "1" would
avoid closing that option off in the future.

I assume there's some reason why you don't want to do that, but I'm to
slow to figure out what it is...?

Thanks,

jon

  parent reply	other threads:[~2021-05-10 15:46 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-08 12:15 [PATCH v3 1/5] cgroup: introduce cgroup.kill Christian Brauner
2021-05-08 12:15 ` Christian Brauner
2021-05-08 12:15 ` [PATCH v3 2/5] docs/cgroup: add entry for cgroup.kill Christian Brauner
2021-05-08 12:15   ` Christian Brauner
2021-05-08 12:15 ` [PATCH v3 3/5] tests/cgroup: use cgroup.kill in cg_killall() Christian Brauner
2021-05-08 12:15   ` Christian Brauner
2021-05-08 12:15 ` [PATCH v3 4/5] tests/cgroup: move cg_wait_for(), cg_prepare_for_wait() Christian Brauner
2021-05-08 12:15   ` Christian Brauner
2021-05-08 12:15 ` [PATCH v3 5/5] tests/cgroup: test cgroup.kill Christian Brauner
2021-05-08 12:15   ` Christian Brauner
2021-05-10 22:02   ` Shakeel Butt
2021-05-10 22:02     ` Shakeel Butt
2021-05-10 14:42 ` [PATCH v3 1/5] cgroup: introduce cgroup.kill Tejun Heo
2021-05-10 14:42   ` Tejun Heo
2021-05-10 14:49   ` Christian Brauner
2021-05-10 14:49     ` Christian Brauner
2021-05-10 15:39 ` Jonathan Corbet [this message]
2021-05-10 15:39   ` Jonathan Corbet
2021-05-10 16:43   ` Roman Gushchin
2021-05-10 16:43     ` Roman Gushchin

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=874kfaha3t.fsf@meer.lwn.net \
    --to=corbet@lwn.net \
    --cc=brauner@kernel.org \
    --cc=cgroups@vger.kernel.org \
    --cc=christian.brauner@ubuntu.com \
    --cc=containers@lists.linux.dev \
    --cc=guro@fb.com \
    --cc=hannes@cmpxchg.org \
    --cc=lizefan.x@bytedance.com \
    --cc=serge@hallyn.com \
    --cc=shakeelb@google.com \
    --cc=tj@kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.