All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
	Petr Mladek <pmladek@suse.com>,
	cgroups@vger.kernel.org, Cyril Hrubis <chrubis@suse.cz>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] memcg: relocate charge moving from ->attach to ->post_attach
Date: Mon, 25 Apr 2016 15:42:49 -0400	[thread overview]
Message-ID: <20160425194249.GG7822@mtj.duckdns.org> (raw)
In-Reply-To: <20160425082542.GB23933@dhcp22.suse.cz>

Hello, Michal.

On Mon, Apr 25, 2016 at 10:25:42AM +0200, Michal Hocko wrote:
> > * move_charge_struct->mm is added and ->can_attach is now responsible
> >   for pinning and recording the target mm.  mem_cgroup_clear_mc() is
> >   updated accordingly.  This also simplifies mem_cgroup_move_task().
> > 
> > * mem_cgroup_move_task() is now called from ->post_attach instead of
> >   ->attach.
> 
> This looks much better than the previous quick&dirty workaround. Thanks
> for taking an extra step!
> 
> Sorry for being so pushy but shouldn't we at least document those
> callbacks which depend on cgroup_threadgroup_rwsem to never ever block
> on WQ directly or indirectly. Maybe even enforce they have to be
> non-blocking. This would be out of scope of this particular patch of
> course but it would fit nicely into the series.

Yeah, I'll look into whether I can annotate this dependency with
lockdep.  If that isn't doable, I'll document the requirements.
cgroup methods have changed a lot and need to be redocumented anyway.

Thanks.

-- 
tejun

WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
	Petr Mladek <pmladek-IBi9RG/b67k@public.gmane.org>,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Cyril Hrubis <chrubis-AlSwsSmVLrQ@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 2/2] memcg: relocate charge moving from ->attach to ->post_attach
Date: Mon, 25 Apr 2016 15:42:49 -0400	[thread overview]
Message-ID: <20160425194249.GG7822@mtj.duckdns.org> (raw)
In-Reply-To: <20160425082542.GB23933-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>

Hello, Michal.

On Mon, Apr 25, 2016 at 10:25:42AM +0200, Michal Hocko wrote:
> > * move_charge_struct->mm is added and ->can_attach is now responsible
> >   for pinning and recording the target mm.  mem_cgroup_clear_mc() is
> >   updated accordingly.  This also simplifies mem_cgroup_move_task().
> > 
> > * mem_cgroup_move_task() is now called from ->post_attach instead of
> >   ->attach.
> 
> This looks much better than the previous quick&dirty workaround. Thanks
> for taking an extra step!
> 
> Sorry for being so pushy but shouldn't we at least document those
> callbacks which depend on cgroup_threadgroup_rwsem to never ever block
> on WQ directly or indirectly. Maybe even enforce they have to be
> non-blocking. This would be out of scope of this particular patch of
> course but it would fit nicely into the series.

Yeah, I'll look into whether I can annotate this dependency with
lockdep.  If that isn't doable, I'll document the requirements.
cgroup methods have changed a lot and need to be redocumented anyway.

Thanks.

-- 
tejun

  reply	other threads:[~2016-04-25 19:42 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-13  9:42 [BUG] cgroup/workques/fork: deadlock when moving cgroups Petr Mladek
2016-04-13 18:33 ` Tejun Heo
2016-04-13 18:33   ` Tejun Heo
2016-04-13 18:57   ` Tejun Heo
2016-04-13 18:57     ` Tejun Heo
2016-04-13 19:23   ` Michal Hocko
2016-04-13 19:23     ` Michal Hocko
2016-04-13 19:28     ` Michal Hocko
2016-04-13 19:28       ` Michal Hocko
2016-04-13 19:37     ` Tejun Heo
2016-04-13 19:48       ` Michal Hocko
2016-04-14  7:06         ` Michal Hocko
2016-04-14  7:06           ` Michal Hocko
2016-04-14 15:32           ` Tejun Heo
2016-04-14 15:32             ` Tejun Heo
2016-04-14 17:50     ` Johannes Weiner
2016-04-15  7:06       ` Michal Hocko
2016-04-15 14:38         ` Tejun Heo
2016-04-15 14:38           ` Tejun Heo
2016-04-15 15:08           ` Michal Hocko
2016-04-15 15:08             ` Michal Hocko
2016-04-15 15:25             ` Tejun Heo
2016-04-15 15:25               ` Tejun Heo
2016-04-17 12:00               ` Michal Hocko
2016-04-17 12:00                 ` Michal Hocko
2016-04-18 14:40           ` Petr Mladek
2016-04-18 14:40             ` Petr Mladek
2016-04-19 14:01             ` Michal Hocko
2016-04-19 14:01               ` Michal Hocko
2016-04-19 15:39               ` Petr Mladek
2016-04-15 19:17       ` [PATCH for-4.6-fixes] memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() Tejun Heo
2016-04-17 12:07         ` Michal Hocko
2016-04-17 12:07           ` Michal Hocko
2016-04-20 21:29           ` Tejun Heo
2016-04-20 21:29             ` Tejun Heo
2016-04-21  3:27             ` Michal Hocko
2016-04-21  3:27               ` Michal Hocko
2016-04-21 15:00               ` Petr Mladek
2016-04-21 15:00                 ` Petr Mladek
2016-04-21 15:51                 ` Tejun Heo
2016-04-21 23:06           ` [PATCH 1/2] cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback Tejun Heo
2016-04-21 23:06             ` Tejun Heo
2016-04-21 23:09             ` [PATCH 2/2] memcg: relocate charge moving from ->attach to ->post_attach Tejun Heo
2016-04-21 23:09               ` Tejun Heo
2016-04-22 13:57               ` Petr Mladek
2016-04-22 13:57                 ` Petr Mladek
2016-04-25  8:25               ` Michal Hocko
2016-04-25  8:25                 ` Michal Hocko
2016-04-25 19:42                 ` Tejun Heo [this message]
2016-04-25 19:42                   ` Tejun Heo
2016-04-25 19:44               ` Tejun Heo
2016-04-25 19:44                 ` Tejun Heo
2016-04-21 23:11             ` [PATCH 1/2] cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback Tejun Heo
2016-04-21 23:11               ` Tejun Heo
2016-04-21 15:56         ` [PATCH for-4.6-fixes] memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() Tejun Heo
2016-04-21 15:56           ` Tejun Heo

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=20160425194249.GG7822@mtj.duckdns.org \
    --to=tj@kernel.org \
    --cc=cgroups@vger.kernel.org \
    --cc=chrubis@suse.cz \
    --cc=hannes@cmpxchg.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mhocko@kernel.org \
    --cc=pmladek@suse.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 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.