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=FROM_EXCESS_BASE64, 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 9A3A0C76191 for ; Thu, 25 Jul 2019 02:33:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A1012238C for ; Thu, 25 Jul 2019 02:33:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389196AbfGYCdS (ORCPT ); Wed, 24 Jul 2019 22:33:18 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:59362 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388369AbfGYCdR (ORCPT ); Wed, 24 Jul 2019 22:33:17 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07417;MF=yun.wang@linux.alibaba.com;NM=1;PH=DS;RN=13;SR=0;TI=SMTPD_---0TXkJoVQ_1564021990; Received: from testdeMacBook-Pro.local(mailfrom:yun.wang@linux.alibaba.com fp:SMTPD_---0TXkJoVQ_1564021990) by smtp.aliyun-inc.com(127.0.0.1); Thu, 25 Jul 2019 10:33:11 +0800 Subject: Re: [PATCH v2 0/4] per-cgroup numa suite From: =?UTF-8?B?546L6LSH?= To: Peter Zijlstra , hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, Ingo Molnar Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, mcgrof@kernel.org, keescook@chromium.org, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, =?UTF-8?Q?Michal_Koutn=c3=bd?= , Hillf Danton References: <209d247e-c1b2-3235-2722-dd7c1f896483@linux.alibaba.com> <60b59306-5e36-e587-9145-e90657daec41@linux.alibaba.com> <65c1987f-bcce-2165-8c30-cf8cf3454591@linux.alibaba.com> Message-ID: <2203b828-1458-5fec-f4f6-353f51091e2a@linux.alibaba.com> Date: Thu, 25 Jul 2019 10:33:10 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <65c1987f-bcce-2165-8c30-cf8cf3454591@linux.alibaba.com> 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 Hi, Peter Now we have all these stuff in cpu cgroup, with the new statistic folks should be able to estimate their per-cgroup workloads on numa platform, and numa group + cling would help to address the issue when their workloads can't be settled on one node. How do you think about this version :-) Regards, Michael Wang On 2019/7/16 上午11:38, ηŽ‹θ΄‡ wrote: > During our torturing on numa stuff, we found problems like: > > * missing per-cgroup information about the per-node execution status > * missing per-cgroup information about the numa locality > > That is when we have a cpu cgroup running with bunch of tasks, no good > way to tell how it's tasks are dealing with numa. > > The first two patches are trying to complete the missing pieces, but > more problems appeared after monitoring these status: > > * tasks not always running on the preferred numa node > * tasks from same cgroup running on different nodes > > The task numa group handler will always check if tasks are sharing pages > and try to pack them into a single numa group, so they will have chance to > settle down on the same node, but this failed in some cases: > > * workloads share page caches rather than share mappings > * workloads got too many wakeup across nodes > > Since page caches are not traced by numa balancing, there are no way to > realize such kind of relationship, and when there are too many wakeup, > task will be drag from the preferred node and then migrate back by numa > balancing, repeatedly. > > Here the third patch try to address the first issue, we could now give hint > to kernel about the relationship of tasks, and pack them into single numa > group. > > And the forth patch introduced numa cling, which try to address the wakup > issue, now we try to make task stay on the preferred node on wakeup in fast > path, in order to address the unbalancing risk, we monitoring the numa > migration failure ratio, and pause numa cling when it reach the specified > degree. > > Since v1: > * move statistics from memory cgroup into cpu group > * statistics now accounting in hierarchical way > * locality now accounted into 8 regions equally > * numa cling no longer override select_idle_sibling, instead we > prevent numa swap migration with tasks cling to dst-node, also > prevent wake affine to drag tasks away which already cling to > prev-cpu > * other refine on comments and names > > Michael Wang (4): > v2 numa: introduce per-cgroup numa balancing locality statistic > v2 numa: append per-node execution time in cpu.numa_stat > v2 numa: introduce numa group per task group > v4 numa: introduce numa cling feature > > include/linux/sched.h | 8 +- > include/linux/sched/sysctl.h | 3 + > kernel/sched/core.c | 85 ++++++++ > kernel/sched/debug.c | 7 + > kernel/sched/fair.c | 510 ++++++++++++++++++++++++++++++++++++++++++- > kernel/sched/sched.h | 41 ++++ > kernel/sysctl.c | 9 + > 7 files changed, 651 insertions(+), 12 deletions(-) >