From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id 3B83B6B0038 for ; Mon, 29 Dec 2014 03:47:37 -0500 (EST) Received: by mail-pd0-f173.google.com with SMTP id ft15so16647828pdb.18 for ; Mon, 29 Dec 2014 00:47:36 -0800 (PST) Received: from mx2.parallels.com (mx2.parallels.com. [199.115.105.18]) by mx.google.com with ESMTPS id qs1si52102346pbb.167.2014.12.29.00.47.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Dec 2014 00:47:35 -0800 (PST) Date: Mon, 29 Dec 2014 11:47:28 +0300 From: Vladimir Davydov Subject: Re: [RFC PATCH 1/2] memcg: account swap instead of memory+swap Message-ID: <20141229084728.GB9984@esperanza> References: <20141228190020.GA9385@phnom.home.cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20141228190020.GA9385@phnom.home.cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: linux-kernel@vger.kernel.org, Michal Hocko , Greg Thelen , Tejun Heo , Andrew Morton , linux-mm@kvack.org On Sun, Dec 28, 2014 at 02:00:20PM -0500, Johannes Weiner wrote: > On Sun, Dec 28, 2014 at 07:19:12PM +0300, Vladimir Davydov wrote: > > The design of swap limits for memory cgroups looks broken. Instead of a > > separate swap limit, there is the memory.memsw.limit_in_bytes knob, > > which limits total memory+swap consumption. As a result, under global > > memory pressure, a cgroup can eat up to memsw.limit of *swap*, so it's > > just impossible to set the swap limit to be less than the memory limit > > with such a design. In particular, this means that we have to leave swap > > unlimited if we want to partition system memory dynamically using soft > > limits. > > > > This patch therefore attempts to move from memory+swap to pure swap > > accounting so that we will be able to separate memory and swap resources > > in the sane cgroup hierarchy, which is the business of the following > > patch. > > > > The old interface acts on memory and swap limits as follows: > > The implementation seems fine to me, but there is no point in cramming > this into the old interface. Let's just leave it alone and implement > proper swap accounting and limiting in the default/unified hierarchy. Agree - the patch will be cleaner, and we won't need to bother about compatibility issues then. Thanks, Vladimir -- 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