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Date:   Mon, 4 Jun 2018 11:47:38 -0700
From:   Tejun Heo <tj@kernel.org>
To:     Michal Hocko <mhocko@kernel.org>
Cc:     "Eric W. Biederman" <ebiederm@xmission.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>, peterz@infradead.org,
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        Balbir Singh <balbir@linux.vnet.ibm.com>,
        Oleg Nesterov <oleg@redhat.com>
Subject: Re: [RFC][PATCH 1/2] memcg: Ensure every task that uses an mm is in
 the same memory cgroup
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Hello, Michal.

On Mon, Jun 04, 2018 at 03:01:19PM +0200, Michal Hocko wrote:
> > On Fri, Jun 01, 2018 at 01:11:59PM -0500, Eric W. Biederman wrote:
> > > Widening the definition of a process sounds good.  The memory control
> > > group code would still need a way to forbid these in cgroup v1 mode,
> > > when someone uses the task file.
> > 
> > Yeap, you're right.  We'll need memcg's can_attach rejecting for v1.
> 
> Do we really need? I mean, do we know about any existing usecase that
> would need this weird threading concept and depend on memory migration
> which doesn't really work?

I thought the requirement is from the ->owner change so that the
association doesn't become 1:N, right?

Thanks.

-- 
tejun