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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 2B0A6C433B4 for ; Thu, 22 Apr 2021 20:57:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A86AF613B0 for ; Thu, 22 Apr 2021 20:57:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A86AF613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 074288E0001; Thu, 22 Apr 2021 16:57:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 023DE8D0001; Thu, 22 Apr 2021 16:57:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E2E4C8E0001; Thu, 22 Apr 2021 16:57:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0117.hostedemail.com [216.40.44.117]) by kanga.kvack.org (Postfix) with ESMTP id C4F898D0001 for ; Thu, 22 Apr 2021 16:57:36 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 844C98248047 for ; Thu, 22 Apr 2021 20:57:36 +0000 (UTC) X-FDA: 78061214112.08.7A2B2B5 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) by imf10.hostedemail.com (Postfix) with ESMTP id E3F6E40002E0 for ; Thu, 22 Apr 2021 20:57:27 +0000 (UTC) Received: by mail-wr1-f43.google.com with SMTP id e7so37142741wrs.11 for ; Thu, 22 Apr 2021 13:57:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=qPJnxVIEMRL17vY4saKs+ZjepvAYDqLQ81lTbkjcV9c=; b=qohcsG17/PEUI6y6/1P7el67bOAnHZyqo58Fe+T8VOU1HqNTnbNTHRFFT6TwJSffaD HZhmBgC8+talqYkeCLKcuuPbfIOVQUsy9j8wpU/v1CUf2nqwCs56FwIQO1fd8Gs9RVfV AJzeBWWXblGz3tzs7go/G34WyGRVYcszD3h4gnmLPLuhQnPp0GYMtM4jYs1AQtXcw6tQ ij+N8tLsYv/vDIt/F6ApZ28cbxbdYaUWRFjtxuvwwM7FElTPzkDoiGj6XxdlGKfaWH/v 41Itr9vSnK2gZBhpZ3rH7drGf13UBR+ROLloDj4Xsey3zO+5Lh+4MboB0MlSigulV7q9 DazQ== 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=qPJnxVIEMRL17vY4saKs+ZjepvAYDqLQ81lTbkjcV9c=; b=jmHq0ZXxZOPMOpayQyPKogDnEZT+xrF1LI148hwo1wCWq4VBAOvp2yoCpe1Rbe6owp MxmhPawGQW1npkEPyyF9JfAZY8qwLMsPHHFrpO1qdJZoCw8ShDDev7TQlmOSt3yJKfIJ k55qCsU8KDUIK4WAaBszRlTgL3givp7Ci8IcEp7ywARij3iZZJ4viU0lHvNWq032cro1 ATf7PYZfa2Y5F8Nw91EmP4Bs/Gz3Q7V0ABVUe0vroOUB/x3LFD9rPU2EREOaWpFsO3xq LuG7fLNdca//l/2LhxvQBrqgv1t+dj+MJNd3v4fwd8yVmwP5Jj2OAbuJ9aZwg37S0dKc fyOQ== X-Gm-Message-State: AOAM5329q0RsM8hWnhXGVhwQk84BlK+sKNsK5JMMBWNrpaWN8WA4ACga nCO04/TgcZ9g51ApJ5gzybWA0IGC2qEHJvwiiUJz9w== X-Google-Smtp-Source: ABdhPJy59nGOJlolqUk8q5RqI/T+Za+uX8bGC3+QzX4KWs7nlt+IQ/H3Fhx4l5gNSsW/yYfIJuTNIB4cSuGSKaqjDKI= X-Received: by 2002:adf:9148:: with SMTP id j66mr345078wrj.124.1619125054685; Thu, 22 Apr 2021 13:57:34 -0700 (PDT) MIME-Version: 1.0 References: <20210416023536.168632-1-zhengjun.xing@linux.intel.com> <7b7a1c09-3d16-e199-15d2-ccea906d4a66@linux.intel.com> <2ea3318a-b17c-ec4c-5425-cb93e079a994@linux.intel.com> In-Reply-To: <2ea3318a-b17c-ec4c-5425-cb93e079a994@linux.intel.com> From: Yu Zhao Date: Thu, 22 Apr 2021 14:57:22 -0600 Message-ID: Subject: Re: [RFC] mm/vmscan.c: avoid possible long latency caused by too_many_isolated() To: Xing Zhengjun Cc: Andrew Morton , Linux-MM , linux-kernel , Huang Ying , Michal Hocko , wfg@mail.ustc.edu.cn, Shakeel Butt , Tim Chen , Hugh Dickins Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: n5nzoreczt3mcnj56716hpe5ap16s6i4 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: E3F6E40002E0 Received-SPF: none (google.com>: No applicable sender policy available) receiver=imf10; identity=mailfrom; envelope-from=""; helo=mail-wr1-f43.google.com; client-ip=209.85.221.43 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619125047-410005 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 Thu, Apr 22, 2021 at 2:38 PM Tim Chen wrote: > > > > On 4/22/21 1:30 PM, Yu Zhao wrote: > > > > HZ/10 is purely arbitrary but that's ok because we assume normally > > nobody hits it. If you do often, we need to figure out why and how not > > to hit it so often. > > > > Perhaps Zhengjun can test the proposed fix in his test case to see if the timeout value > makes any difference. Shakeel has another test to stress page reclaim to a point that the kernel can livelock for two hours because of a large number of concurrent reclaimers stepping on each other. He might be able to share that test with you in case you are interested. Also it's Hugh who first noticed that migration can isolate many pages and in turn block page reclaim. He might be able to help too, in case you are interested in the interaction between migration and page reclaim. Thanks.