From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752327AbbKIQpd (ORCPT ); Mon, 9 Nov 2015 11:45:33 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:42510 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751628AbbKIQpb (ORCPT ); Mon, 9 Nov 2015 11:45:31 -0500 Date: Mon, 9 Nov 2015 11:45:18 -0500 From: Johannes Weiner To: Michal Hocko Cc: Vladimir Davydov , Andrew Morton , Tejun Heo , Greg Thelen , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] memcg/kmem: switch to white list policy Message-ID: <20151109164518.GA23356@cmpxchg.org> References: <20151109140832.GE8916@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151109140832.GE8916@dhcp22.suse.cz> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 09, 2015 at 03:08:32PM +0100, Michal Hocko wrote: > I am _all_ for this semantic I am just not sure what to do with the > legacy kmem controller. Can we change its semantic? If we cannot do that > we would have to distinguish legacy and unified hierarchies during > runtime and add the flag automagically for the first one (that would > however require to keep __GFP_NOACCOUNT as well) which is all as clear > as mud. But maybe the workloads which are using kmem legacy API can cope > with that. I think we can make that change for the existing kmem accounting too, simply because the whitelist should be covering all memory consumers that actually matter for isolation in practice. Yes, there is a risk for accidents, but we are not actually intending to change semantics. > Anyway if we go this way then I think the kmem accounting would be safe > to be enabled by default with the cgroup2. Cool, I'm happy we're on the same page about this.