From: Tejun Heo <tj@kernel.org>
To: Li Zefan <lizefan@huawei.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Cgroups <cgroups@vger.kernel.org>
Subject: Re: [PATCH 3/5] cgroup: fix mount failure in a corner case
Date: Fri, 20 Jun 2014 15:10:25 -0400 [thread overview]
Message-ID: <20140620191025.GA28324@mtj.dyndns.org> (raw)
In-Reply-To: <5399496D.6060003@huawei.com>
On Thu, Jun 12, 2014 at 02:32:13PM +0800, Li Zefan wrote:
> @@ -1677,6 +1679,22 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
> goto out_unlock;
> }
>
> + /*
> + * If some subsystems have been bound to existing cgroup hierarchies,
> + * but those hierachies are being destroyed, let's wait a little bit
> + * and retry.
> + */
> + for_each_subsys(ss, i) {
> + if (!(opts.subsys_mask & (1 << i)))
> + continue;
> + if (!percpu_ref_alive(&ss->root->cgrp.self.refcnt)) {
Can't we just do tryget_live() instead and then put before retrying?
It's not exactly a hot path and the operations are dirt cheap anyway.
Thanks.
--
tejun
next prev parent reply other threads:[~2014-06-20 19:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-12 6:31 [PATCH 1/5] cgroup: fix broken css_has_online_children() Li Zefan
2014-06-12 6:31 ` [PATCH 2/5] percpu-ref: introduce percpu_ref_alive() Li Zefan
2014-06-12 6:32 ` [PATCH 3/5] cgroup: fix mount failure in a corner case Li Zefan
2014-06-20 19:10 ` Tejun Heo [this message]
2014-06-24 1:15 ` Li Zefan
2014-06-12 6:32 ` [PATCH 4/5] kernfs: introduce kernfs_pin_sb() and kernfs_drop_sb() Li Zefan
2014-06-12 6:33 ` [PATCH 5/5] cgroup: fix a race between cgroup_mount() and cgroup_kill_sb() Li Zefan
2014-06-20 19:35 ` Tejun Heo
2014-06-24 1:22 ` Li Zefan
2014-06-24 21:01 ` Tejun Heo
2014-06-25 1:56 ` Li Zefan
2014-06-25 15:00 ` Tejun Heo
2014-06-27 6:32 ` Li Zefan
2014-06-27 15:00 ` Tejun Heo
2014-06-17 19:26 ` [PATCH 1/5] cgroup: fix broken css_has_online_children() 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=20140620191025.GA28324@mtj.dyndns.org \
--to=tj@kernel.org \
--cc=cgroups@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®