Re: [RFC] Making memcg track ownership per address_space or anon_vma

[Tejun Heo <tj@kernel.org>]

Hello,

On Thu, Feb 12, 2015 at 02:15:29AM +0400, Konstantin Khlebnikov wrote:
> Well, ok. Even if shared writes are rare whey should be handled somehow
> without relying on kupdate-like writeback. If memcg has a lot of dirty pages

This only works iff we consider those cases to be marginal enough to
be handle them in a pretty ghetto way.

> but their inodes are accidentially belong to wrong wb queues when tasks in
> that memcg shouldn't stuck in balance-dirty-pages until somebody outside
> acidentially writes this data. That's all what I wanted to say.

But, right, yeah, corner cases around this could be nasty if writeout
interval is set really high.  I don't think it matters for the default
5s interval at all.  Maybe what we need is queueing a delayed per-wb
work w/ the default writeout interval when dirtying a foreign inode.
I'll think more about it.

Thanks.

-- 
tejun