linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Li Zefan <lizefan@huawei.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Glauber Costa <glommer@parallels.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Michal Hocko <mhocko@suse.cz>,
	Johannes Weiner <hannes@cmpxchg.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Cgroups <cgroups@vger.kernel.org>,
	linux-mm@kvack.org
Subject: Re: [PATCH 2/8] cgroup: implement cgroup_from_id()
Date: Mon, 8 Apr 2013 08:48:47 -0700	[thread overview]
Message-ID: <20130408154847.GE3021@htj.dyndns.org> (raw)
In-Reply-To: <51627DEB.4090104@huawei.com>

Oops, one more thing.

On Mon, Apr 08, 2013 at 04:20:59PM +0800, Li Zefan wrote:
> -	cgrp->id = ida_simple_get(&root->cgroup_ida, 1, 0, GFP_KERNEL);
> +	cgrp->id = idr_alloc(&root->cgroup_idr, cgrp, 1, 0, GFP_KERNEL);

This will allow lookups to return half-initialized cgroup, which
shouldn't happen.  Either idr_alloc() should be moved to after
initialization of other fields are finished, or it should be called
with NULL @ptr with idr_replace() added at the end to install @cgrp.

Similarly, the removal path should guarantee that the object is
removed from idr *before* its grace period starts.

Thanks.

-- 
tejun

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2013-04-08 15:48 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-08  8:19 [PATCH 0/8] memcg, cgroup: kill css_id Li Zefan
2013-04-08  8:20 ` [PATCH 1/8] cgroup: implement cgroup_is_ancestor() Li Zefan
2013-04-08 14:47   ` Michal Hocko
2013-04-08 15:57     ` Tejun Heo
2013-04-08 16:33       ` Michal Hocko
2013-04-08 18:03     ` Michal Hocko
2013-04-08 21:36       ` Tejun Heo
2013-04-09  6:42         ` Michal Hocko
2013-04-08 15:39   ` Tejun Heo
2013-04-09  3:21   ` Kamezawa Hiroyuki
2013-04-09  3:29     ` Li Zefan
2013-04-08  8:20 ` [PATCH 2/8] cgroup: implement cgroup_from_id() Li Zefan
2013-04-08 15:43   ` Tejun Heo
2013-04-09  3:12     ` Li Zefan
2013-04-08 15:48   ` Tejun Heo [this message]
2013-04-09  3:56   ` Kamezawa Hiroyuki
2013-04-09  4:08   ` Kamezawa Hiroyuki
2013-04-08  8:21 ` [PATCH 3/8] memcg: convert to use cgroup_is_ancestor() Li Zefan
2013-04-09  3:58   ` Kamezawa Hiroyuki
2013-04-09  6:49   ` Michal Hocko
2013-04-08  8:21 ` [PATCH 4/8] memcg: convert to use cgroup_from_id() Li Zefan
2013-04-08 14:53   ` Michal Hocko
2013-04-09  3:00     ` Li Zefan
2013-04-09  3:59   ` Kamezawa Hiroyuki
2013-04-08  8:22 ` [PATCH 5/8] memcg: convert to use cgroup->id Li Zefan
2013-04-08 14:57   ` Michal Hocko
2013-04-09  3:02     ` Li Zefan
2013-04-09  6:49       ` Michal Hocko
2013-04-09  4:02   ` Kamezawa Hiroyuki
2013-04-08  8:22 ` [PATCH 6/8] memcg: fail to create cgroup if the cgroup id is too big Li Zefan
2013-04-08 15:01   ` Michal Hocko
2013-04-08  8:23 ` [PATCH 7/8] memcg: don't use css_id any more Li Zefan
2013-04-08 15:01   ` Michal Hocko
2013-04-09  4:11   ` Kamezawa Hiroyuki
2013-04-08  8:23 ` [PATCH 8/8] cgroup: kill css_id Li Zefan
2013-04-08 15:51   ` Tejun Heo
2013-04-08 14:37 ` [PATCH 0/8] memcg, " Michal Hocko

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=20130408154847.GE3021@htj.dyndns.org \
    --to=tj@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=cgroups@vger.kernel.org \
    --cc=glommer@parallels.com \
    --cc=hannes@cmpxchg.org \
    --cc=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lizefan@huawei.com \
    --cc=mhocko@suse.cz \
    /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;
as well as URLs for NNTP newsgroup(s).