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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6420FC433C1 for ; Mon, 22 Mar 2021 01:46:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E26C261937 for ; Mon, 22 Mar 2021 01:46:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E26C261937 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6F9F26B0036; Sun, 21 Mar 2021 21:46:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6AA796B006C; Sun, 21 Mar 2021 21:46:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 522CE6B0070; Sun, 21 Mar 2021 21:46:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id 2FE726B0036 for ; Sun, 21 Mar 2021 21:46:43 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D9C76180322D5 for ; Mon, 22 Mar 2021 01:46:42 +0000 (UTC) X-FDA: 77945821044.06.9945596 Received: from mail-ua1-f41.google.com (mail-ua1-f41.google.com [209.85.222.41]) by imf19.hostedemail.com (Postfix) with ESMTP id 7F03290009D6 for ; Mon, 22 Mar 2021 01:46:42 +0000 (UTC) Received: by mail-ua1-f41.google.com with SMTP id h34so5046180uah.5 for ; Sun, 21 Mar 2021 18:46:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=KDT2f09MXVbOmHcou2TiE6dueEKdk8Bes3XxuA8S9lo=; b=bf5Rb7uOgJNkcZyD4ssx3OUSPJ3NXi8uOLDGOCe74yS7Ui4G/F2BvZ8vn3g3421i1r 205+5mdbPnI2OsA5JkCX/1fozlkOcvCTiUsrBK1eiVLiR+f2qZQP15suPSNFTwX8LGRE 5wwwmWtwtneH4XB5gNJrRWjNVSsEob53szL84KUX8M7gUY4o6jaArROhgeVoeUdjJ5Ao tFGls/mfSSTD7nzH9d0rPW7A93nbBRmKKBUsCkw5IQeQk9ZjeH2v97S08WwKomH+nYrv 6VhLomWCrgXHoX0KS/mibNaB2NQrXtZU2dD7fegVkN9vo8wa9hdfbBe6pF0AMWhdrmbK bMUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KDT2f09MXVbOmHcou2TiE6dueEKdk8Bes3XxuA8S9lo=; b=ckSgS4ow9Q6aRI1RhGw0yyq6OZDVQhBs2RArNnPRktDzYt7NxPnfTKzCUBMa0rwciv 9klUVRTi061hwv4OULTKVT5KZlii51TmBg+oks7NN7iLjnj+Gx3/HynD6ksHK7RmwtlM L+tDpa4agHzvMtyavwCcz5TI074zAqljc6JgL1Gaf+d95OH7LcDiZFcbJJ3b/U6kiZm+ Faj3NIzB+OUYjuHvdewwF8v2T/TIjBO4bXspK0LP0q7eplLnXoo6Uc2wODVbEJ3vrVYT YPJOjGwCWaSilmi5/bquZ3esyBs2VFoSQOAIS+a/1WQWrTB0CNk8hDXB1Bf1NlaRRi4P 0MRw== X-Gm-Message-State: AOAM533uJumLlMXTJ5wohYJSywmtSdXV+XZpe0X8SquQik8rPnjA17Y6 mMPYgnvRYiw/6qGbjaeDZC/tNj8S+IZ8wH5EewE= X-Google-Smtp-Source: ABdhPJy3cbxmAhndYEZo9ey6gJkAl7UFtYdJxY1Fx9L7qqzObfPrK2ZX0mNGJ3dAssqcSvH2rRfsA6vjrldhU05TIzs= X-Received: by 2002:ab0:66c9:: with SMTP id d9mr3823838uaq.29.1616377599379; Sun, 21 Mar 2021 18:46:39 -0700 (PDT) MIME-Version: 1.0 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> <34a07677-3afe-465c-933e-dc9503e9634d@linux.alibaba.com> In-Reply-To: <34a07677-3afe-465c-933e-dc9503e9634d@linux.alibaba.com> From: Shu Ming Date: Mon, 22 Mar 2021 09:46:27 +0800 Message-ID: Subject: Re: [PATCH v4 1/3] mm/slub: Introduce two counters for partial objects To: Xunlei Pang Cc: Vlastimil Babka , Christoph Lameter , Christoph Lameter , Pekka Enberg , Roman Gushchin , Konstantin Khlebnikov , David Rientjes , Matthew Wilcox , Andrew Morton , LKML , linux-mm@kvack.org, Wen Yang , James Wang Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: aboe96bayrsp9ecrposbr77hf5dxz1z5 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 7F03290009D6 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf19; identity=mailfrom; envelope-from=""; helo=mail-ua1-f41.google.com; client-ip=209.85.222.41 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616377602-315078 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: More precisely, ss will count partial objects like denty objects with "/sys/kernel/slab/dentry/partial" whose number can become huge. On Thu, Mar 18, 2021 at 8:56 PM Xunlei Pang wrote: > > > > 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.