From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH 2/2] cpuset: fix cpu hotplug vs rebuild_sched_domains()
 race
Date: Sat, 27 Apr 2013 07:23:25 -0700
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To: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: Li Zhong <zhong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>

On Sat, Apr 27, 2013 at 05:53:48PM +0800, Li Zefan wrote:
> rebuild_sched_domains() might pass doms with offlined cpu to
> partition_sched_domains(), which results in an oops:
> 
> general protection fault: 0000 [#1] SMP
> ...
> RIP: 0010:[<ffffffff81077a1e>]  [<ffffffff81077a1e>] get_group+0x6e/0x90
> ...
> Call Trace:
>  [<ffffffff8107f07c>] build_sched_domains+0x70c/0xcb0
>  [<ffffffff8107f2a7>] ? build_sched_domains+0x937/0xcb0
>  [<ffffffff81173f64>] ? kfree+0xe4/0x1b0
>  [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470
>  [<ffffffff8107f905>] partition_sched_domains+0x2e5/0x470
>  [<ffffffff8107f6e0>] ? partition_sched_domains+0xc0/0x470
>  [<ffffffff810c9007>] ? generate_sched_domains+0xc7/0x530
>  [<ffffffff810c94a8>] rebuild_sched_domains_locked+0x38/0x70
>  [<ffffffff810cb4a4>] cpuset_write_resmask+0x1a4/0x500
>  [<ffffffff810c8700>] ? cpuset_mount+0xe0/0xe0
>  [<ffffffff810c7f50>] ? cpuset_read_u64+0x100/0x100
>  [<ffffffff810be890>] ? cgroup_iter_next+0x90/0x90
>  [<ffffffff810cb300>] ? cpuset_css_offline+0x70/0x70
>  [<ffffffff810c1a73>] cgroup_file_write+0x133/0x2e0
>  [<ffffffff8118995b>] vfs_write+0xcb/0x130
>  [<ffffffff8118a174>] sys_write+0x64/0xa0
> 
> Reported-by: Li Zhong <zhong-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Applied 1-2 to cgroup/for-3.10.

Thanks.

-- 
tejun