Re: [PATCH for-4.6] cgroup: ignore css_sets associated with dead cgroups during migration

[Tejun Heo]

On Wed, Mar 16, 2016 at 11:45:27AM +0100, Peter Zijlstra wrote:
> This doesn't fix the problem that those zombies might actually still
> want to use the cgroups they're tied to, as reported here:
> 
>   lkml.kernel.org/r/20160314112057.GT6356@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> 
> I would strongly suggest to revert 2e91fa7f6d45 wholesale (and mark for
> stable) and try again later.

For the record, this issue was caused by the cpu controller taking
down its css too early during destruction at ->css_offline() and is
fixed by switching to ->css_released() instead.

Thanks.

-- 
tejun