Re: [-mm] Add an owner to the mm_struct (v7)

From: Balbir Singh
Date: Thu Apr 03 2008 - 14:12:29 EST


Paul Menage wrote:
> On Thu, Apr 3, 2008 at 10:44 AM, Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
>> +
>> + /*
>> + * If there are other users of the mm and the owner (us) is exiting
>> + * we need to find a new owner to take on the responsibility.
>> + * When we use thread groups (CLONE_THREAD), the thread group
>> + * leader is kept around in zombie state, even after it exits.
>> + * delay_group_leader() ensures that if the group leader is around
>> + * we need not select a new owner.
>> + */
>
> Hmm, is this new check for delay_group_leader() safe? Won't we have
> called exit_cgroup() by this point, and hence be reassigned to the
> root cgroup? And so mm->owner->cgroups won't point to the right place?
>

cgroup_exit() comes in much later after exit_mm(). Moreover delay_group_leader()
is a function that checks to see if

We are the group leader and the thread group is not empty.

--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/