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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 C98CEC433E6 for ; Thu, 18 Mar 2021 12:57:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C27F64EE2 for ; Thu, 18 Mar 2021 12:57:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231377AbhCRM4t (ORCPT ); Thu, 18 Mar 2021 08:56:49 -0400 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:40094 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231269AbhCRM4Y (ORCPT ); Thu, 18 Mar 2021 08:56:24 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xlpang@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0USS3ezc_1616072180; Received: from xunleideMacBook-Pro.local(mailfrom:xlpang@linux.alibaba.com fp:SMTPD_---0USS3ezc_1616072180) by smtp.aliyun-inc.com(127.0.0.1); Thu, 18 Mar 2021 20:56:21 +0800 Reply-To: xlpang@linux.alibaba.com Subject: Re: [PATCH v4 1/3] mm/slub: Introduce two counters for partial objects To: Vlastimil Babka , Xunlei Pang , Christoph Lameter , Christoph Lameter , Pekka Enberg , Roman Gushchin , Konstantin Khlebnikov , David Rientjes , Matthew Wilcox , Shu Ming , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Wen Yang , James Wang References: <1615967692-80524-1-git-send-email-xlpang@linux.alibaba.com> <1615967692-80524-2-git-send-email-xlpang@linux.alibaba.com> <42b5dba7-f89f-ae43-3b93-f6e4868e1573@suse.cz> From: Xunlei Pang Message-ID: <34a07677-3afe-465c-933e-dc9503e9634d@linux.alibaba.com> Date: Thu, 18 Mar 2021 20:56:20 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <42b5dba7-f89f-ae43-3b93-f6e4868e1573@suse.cz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/18/21 8:18 PM, Vlastimil Babka wrote: > On 3/17/21 8:54 AM, Xunlei Pang wrote: >> The node list_lock in count_partial() spends long time iterating >> in case of large amount of partial page lists, which can cause >> thunder herd effect to the list_lock contention. >> >> We have HSF RT(High-speed Service Framework Response-Time) monitors, >> the RT figures fluctuated randomly, then we deployed a tool detecting >> "irq off" and "preempt off" to dump the culprit's calltrace, capturing >> the list_lock cost nearly 100ms with irq off issued by "ss", this also >> caused network timeouts. > > I forgot to ask, how does "ss" come into this? It displays network connections > AFAIK. Does it read any SLUB counters or slabinfo? > ss may access /proc/slabinfo to acquire network related slab statistics.