From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH v3 2/2] memcg: punt high overage reclaim to
 return-to-userland path
Date: Tue, 15 Sep 2015 11:53:55 -0400
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To: Johannes Weiner <hannes@cmpxchg.org>
Cc: akpm@linux-foundation.org, mhocko@kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, vdavydov@parallels.com, kernel-team@fb.com

Hello, Johannes.

On Tue, Sep 15, 2015 at 09:47:24AM +0200, Johannes Weiner wrote:
> Why can't we simply fail NOWAIT allocations when the high limit is
> breached? We do the same for the max limit.

Because that can lead to continued systematic failures of NOWAIT
allocations.  For that to work, we'll have to add async reclaimaing.

> As I see it, NOWAIT allocations are speculative attempts on available
> memory. We should be able to just fail them and have somebody that is
> allowed to reclaim try again, just like with the max limit.

Yes, but the assumption is that even back-to-back NOWAIT allocations
won't continue to fail indefinitely.

Thanks.

-- 
tejun

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