From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932502AbdJJRvs (ORCPT ); Tue, 10 Oct 2017 13:51:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:44287 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932300AbdJJRvr (ORCPT ); Tue, 10 Oct 2017 13:51:47 -0400 Date: Tue, 10 Oct 2017 19:51:43 +0200 From: Michal Hocko To: Dave Hansen Cc: kemi , "Luis R . Rodriguez" , Kees Cook , Andrew Morton , Jonathan Corbet , Mel Gorman , Johannes Weiner , Christopher Lameter , Sebastian Andrzej Siewior , Vlastimil Babka , Tim Chen , Andi Kleen , Jesper Dangaard Brouer , Ying Huang , Aaron Lu , Proc sysctl , Linux MM , Linux Kernel Subject: Re: [PATCH v3] mm, sysctl: make NUMA stats configurable Message-ID: <20171010175143.q4bz43dtn4eyn32j@dhcp22.suse.cz> References: <1506579101-5457-1-git-send-email-kemi.wang@intel.com> <20171003092352.2wh2jbtt2dudfi5a@dhcp22.suse.cz> <221a1e93-ee33-d598-67de-d6071f192040@intel.com> <20171009075549.pzohdnerillwuhqo@dhcp22.suse.cz> <20171010054902.sqp6yyid6qqhpsrt@dhcp22.suse.cz> <20171010143113.gk6iqcrguefhhlmr@dhcp22.suse.cz> <20171010145728.q2levvekbpwlg57q@dhcp22.suse.cz> <4949ccef-6b7f-c2d6-f500-92eadb2ba649@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4949ccef-6b7f-c2d6-f500-92eadb2ba649@linux.intel.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 10-10-17 08:39:47, Dave Hansen wrote: > On 10/10/2017 07:57 AM, Michal Hocko wrote: > >> But, let's be honest, this leaves us with an option that nobody is ever > >> going to turn on. IOW, nobody except a very small portion of our users > >> will ever see any benefit from this. > > But aren't those small groups who would like to squeeze every single > > cycle out from the page allocator path the targeted audience? > > They're the reason we started looking at this. They also care the most. > > But, the cost of these stats, especially we get more and more cores in a > NUMA node is really making them show up in profiles. It would be nice > to get rid of them there, too. I am not opposing to the auto mode. I am just not sure it is a safe default and I also think that we should add this on top if it is really needed. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 10 Oct 2017 19:51:43 +0200 From: Michal Hocko To: Dave Hansen Cc: kemi , "Luis R . Rodriguez" , Kees Cook , Andrew Morton , Jonathan Corbet , Mel Gorman , Johannes Weiner , Christopher Lameter , Sebastian Andrzej Siewior , Vlastimil Babka , Tim Chen , Andi Kleen , Jesper Dangaard Brouer , Ying Huang , Aaron Lu , Proc sysctl , Linux MM , Linux Kernel Subject: Re: [PATCH v3] mm, sysctl: make NUMA stats configurable Message-ID: <20171010175143.q4bz43dtn4eyn32j@dhcp22.suse.cz> References: <1506579101-5457-1-git-send-email-kemi.wang@intel.com> <20171003092352.2wh2jbtt2dudfi5a@dhcp22.suse.cz> <221a1e93-ee33-d598-67de-d6071f192040@intel.com> <20171009075549.pzohdnerillwuhqo@dhcp22.suse.cz> <20171010054902.sqp6yyid6qqhpsrt@dhcp22.suse.cz> <20171010143113.gk6iqcrguefhhlmr@dhcp22.suse.cz> <20171010145728.q2levvekbpwlg57q@dhcp22.suse.cz> <4949ccef-6b7f-c2d6-f500-92eadb2ba649@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4949ccef-6b7f-c2d6-f500-92eadb2ba649@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: On Tue 10-10-17 08:39:47, Dave Hansen wrote: > On 10/10/2017 07:57 AM, Michal Hocko wrote: > >> But, let's be honest, this leaves us with an option that nobody is ever > >> going to turn on. IOW, nobody except a very small portion of our users > >> will ever see any benefit from this. > > But aren't those small groups who would like to squeeze every single > > cycle out from the page allocator path the targeted audience? > > They're the reason we started looking at this. They also care the most. > > But, the cost of these stats, especially we get more and more cores in a > NUMA node is really making them show up in profiles. It would be nice > to get rid of them there, too. I am not opposing to the auto mode. I am just not sure it is a safe default and I also think that we should add this on top if it is really needed. -- 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