Re: [PATCH v2 06/10] cpuset: record old_mems_allowed in struct cpuset

[Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>]

On 2013/6/6 3:45, Tejun Heo wrote:
> Hello, Li.
> 
> On Wed, Jun 05, 2013 at 05:16:24PM +0800, Li Zefan wrote:
>> @@ -1425,7 +1435,6 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
>>  	 * Change mm, possibly for multiple threads in a threadgroup. This is
>>  	 * expensive and may sleep.
>>  	 */
>> -	cpuset_attach_nodemask_to = cs->mems_allowed;
>>  	mm = get_task_mm(leader);
>>  	if (mm) {
>>  		mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
> 
> This looks a bit suspicious to me.  Now we're setting mm's nodemask to
> guarantee_online_mems() output rather than cs->mems_allowed.  Is this
> change intended?  If so, it probably deserves an explanation in the
> description?
> 

It's possible that cs->mems_allowed is empty, but I should have left
it as it is, as it's not related to this patch.