From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
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 6:32 ` [PATCH 3/5] cgroup: fix mount failure in a corner case Li Zefan
[not found] ` <5399496D.6060003-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
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
[not found] ` <53994943.60703-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-06-12 6:31 ` [PATCH 2/5] percpu-ref: introduce percpu_ref_alive() Li Zefan
2014-06-12 6:33 ` [PATCH 5/5] cgroup: fix a race between cgroup_mount() and cgroup_kill_sb() Li Zefan
[not found] ` <539949A1.90301-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-06-20 19:35 ` Tejun Heo
[not found] ` <20140620193521.GB28324-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-06-24 1:22 ` Li Zefan
[not found] ` <53A8D2B8.4080107-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-06-24 21:01 ` Tejun Heo
[not found] ` <20140624210119.GC14909-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-06-25 1:56 ` Li Zefan
2014-06-25 15:00 ` Tejun Heo
[not found] ` <20140625150053.GE26883-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-06-27 6:32 ` Li Zefan
[not found] ` <53AD1001.4090405-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-06-27 15:00 ` Tejun Heo
2014-06-17 19:26 ` [PATCH 1/5] cgroup: fix broken css_has_online_children() Tejun Heo
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