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,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 950E2C433DB for ; Thu, 18 Mar 2021 12:18:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 08BEB64F45 for ; Thu, 18 Mar 2021 12:18:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08BEB64F45 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 60AE96B0072; Thu, 18 Mar 2021 08:18:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B87B6B0073; Thu, 18 Mar 2021 08:18:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 47F426B0074; Thu, 18 Mar 2021 08:18:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 2BEBE6B0072 for ; Thu, 18 Mar 2021 08:18:17 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id DED93181AF5C2 for ; Thu, 18 Mar 2021 12:18:16 +0000 (UTC) X-FDA: 77932897392.12.5790783 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf29.hostedemail.com (Postfix) with ESMTP id 3D565DA for ; Thu, 18 Mar 2021 12:18:15 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id EB572AC75; Thu, 18 Mar 2021 12:18:14 +0000 (UTC) Subject: Re: [PATCH v4 1/3] mm/slub: Introduce two counters for partial objects To: 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> From: Vlastimil Babka Message-ID: <42b5dba7-f89f-ae43-3b93-f6e4868e1573@suse.cz> Date: Thu, 18 Mar 2021 13:18:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <1615967692-80524-2-git-send-email-xlpang@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: jehhmi1bm6b8ehuk9yoc5znhna8nr4m3 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 3D565DA Received-SPF: none (suse.cz>: No applicable sender policy available) receiver=imf29; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: none/none X-HE-Tag: 1616069895-527221 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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?