From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8B4CC35679 for ; Mon, 24 Feb 2020 03:13:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A14B20675 for ; Mon, 24 Feb 2020 03:13:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727235AbgBXDN6 (ORCPT ); Sun, 23 Feb 2020 22:13:58 -0500 Received: from out30-45.freemail.mail.aliyun.com ([115.124.30.45]:51963 "EHLO out30-45.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727156AbgBXDN6 (ORCPT ); Sun, 23 Feb 2020 22:13:58 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R831e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=yun.wang@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0TqhetfV_1582514031; Received: from testdeMacBook-Pro.local(mailfrom:yun.wang@linux.alibaba.com fp:SMTPD_---0TqhetfV_1582514031) by smtp.aliyun-inc.com(127.0.0.1); Mon, 24 Feb 2020 11:13:53 +0800 Subject: Re: [PATCH RESEND v8 1/2] sched/numa: introduce per-cgroup NUMA locality info To: Peter Zijlstra , Mel Gorman Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Luis Chamberlain , Kees Cook , Iurii Zaikin , Michal Koutn? , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, "Paul E. McKenney" , Randy Dunlap , Jonathan Corbet References: <20200214151048.GL14914@hirez.programming.kicks-ass.net> <20200217115810.GA3420@suse.de> <881deb50-163e-442a-41ec-b375cc445e4d@linux.alibaba.com> <20200217141616.GB3420@suse.de> <114519ab-4e9e-996a-67b8-4f5fcecba72a@linux.alibaba.com> <20200221142010.GT3420@suse.de> <20200221154706.GI18400@hirez.programming.kicks-ass.net> From: =?UTF-8?B?546L6LSH?= Message-ID: <9b3fc96e-d705-1b30-da3d-e85ad5549da3@linux.alibaba.com> Date: Mon, 24 Feb 2020 11:13:51 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200221154706.GI18400@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/2/21 下午11:47, Peter Zijlstra wrote: > On Fri, Feb 21, 2020 at 02:20:10PM +0000, Mel Gorman wrote: >> I fully acknowledge that this may have value for sysadmins and may be a >> good enough reason to merge it for environments that typically build and >> configure their own kernels. I doubt that general distributions would >> enable it but that's a guess. > > OTOH, many sysadmins seem to 'rely' on BPF scripts and other such fancy > things these days. > > ( of course, we have the open question on what happens when we break > one of those BPF 'important' scripts ... ) > > My main reservation with this patch is that it exposes, to userspace, an > ABI that is very hard to interpret and subject to implementation > details. > > So while it can be disabled; people who have it enabled might suddenly > complain when we change the meaning/interpretation/whatever of these > magic numbers. > > Michael; you seem to have ignored the tracepoint / BPF angle earlier in > this discussion; that is not something that could/would work for you? At very beginning I think these fancy stuff may consume too much resources them selves, so just as you said, ignored the possibility :-P But now I understand there is a big gap here, which require a much more general way to evaluate the NUMA platform, I'll try to follow this way see if there are any practical approach instead~ Regards, Michael Wang >