From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id A01996B0038 for ; Fri, 12 Jan 2018 07:24:08 -0500 (EST) Received: by mail-wr0-f198.google.com with SMTP id s105so3280644wrc.23 for ; Fri, 12 Jan 2018 04:24:08 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id s1si13896512wre.212.2018.01.12.04.24.07 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 12 Jan 2018 04:24:07 -0800 (PST) Date: Fri, 12 Jan 2018 13:24:05 +0100 From: Michal Hocko Subject: Re: [PATCH v4] mm/memcg: try harder to decrease [memory,memsw].limit_in_bytes Message-ID: <20180112122405.GK1732@dhcp22.suse.cz> References: <20180109152622.31ca558acb0cc25a1b14f38c@linux-foundation.org> <20180110124317.28887-1-aryabinin@virtuozzo.com> <20180111104239.GZ1732@dhcp22.suse.cz> <4a8f667d-c2ae-e3df-00fd-edc01afe19e1@virtuozzo.com> <20180111124629.GA1732@dhcp22.suse.cz> <20180111162947.GG1732@dhcp22.suse.cz> <560a77b5-02d7-cbae-35f3-0b20a1c384c2@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <560a77b5-02d7-cbae-35f3-0b20a1c384c2@virtuozzo.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin Cc: Andrew Morton , Johannes Weiner , Vladimir Davydov , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt On Fri 12-01-18 00:59:38, Andrey Ryabinin wrote: > On 01/11/2018 07:29 PM, Michal Hocko wrote: [...] > > I do not think so. Consider that this reclaim races with other > > reclaimers. Now you are reclaiming a large chunk so you might end up > > reclaiming more than necessary. SWAP_CLUSTER_MAX would reduce the over > > reclaim to be negligible. > > > > I did consider this. And I think, I already explained that sort of race in previous email. > Whether "Task B" is really a task in cgroup or it's actually a bunch of reclaimers, > doesn't matter. That doesn't change anything. I would _really_ prefer two patches here. The first one removing the hard coded reclaim count. That thing is just dubious at best. If you _really_ think that the higher reclaim target is meaningfull then make it a separate patch. I am not conviced but I will not nack it it either. But it will make our life much easier if my over reclaim concern is right and we will need to revert it. Conceptually those two changes are independent anywa. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org