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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 76723C43441 for ; Thu, 11 Oct 2018 01:17:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EE9E20841 for ; Thu, 11 Oct 2018 01:17:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GmWbKUj3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EE9E20841 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726352AbeJKImZ (ORCPT ); Thu, 11 Oct 2018 04:42:25 -0400 Received: from mail-pf1-f170.google.com ([209.85.210.170]:44441 "EHLO mail-pf1-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725971AbeJKImZ (ORCPT ); Thu, 11 Oct 2018 04:42:25 -0400 Received: by mail-pf1-f170.google.com with SMTP id r9-v6so3493458pff.11 for ; Wed, 10 Oct 2018 18:17:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=XX/dFG3dZL3VyUuSTF50QbeJ8+U3c3TVehgXMffTvqQ=; b=GmWbKUj3zU8H1N6I4nPxMMXUiX5m3vwuPOvtiJNuwM7DNPxXQ5JlBv+aPPGrI+sf0J z1pxZlYKWNox3ZIWTyXnQ7usK2EviVwDLKJLvElITLTJidr9vi17HcI55XGM0A4IfUQT kRR8tnj76t30m9+uJtQCLt2PHu4fyDnYT8bmczPF1j6Sl0LjaPpaNc/8nNfTjUB5hArC aQwDRBfEfgEEQte0ZPEGMAbLb1BDfRd+VM8LkW0GjBX8s11ZyQo/7w8aDqFOdygtv+GR 5d4uQJmepPSNgEiI4ToYYERoELMB20vqoR4TxZBpoPzf+S1ZqBRSPtHQiai/xgcEbU0y 9lNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=XX/dFG3dZL3VyUuSTF50QbeJ8+U3c3TVehgXMffTvqQ=; b=X7WxFT9FSwX7IP3JUiSWXvoTlu3x5WmgC0OTJS6mdiZLWULV+5HevaHxVcmijSPqGP se7+9Ax9wsEaD0Avsjuht2wUXSLrZZTkIUUSiF6xReEa8k+zpGZEf31zdVA78YR1BzPb fzGsePbZ+kvEC4J3TMT+jpw22kAIz8wljrn3DNpF+tEzH3JuawcjUxZFDh/bISOzM+yp nsKwOteNicoFeKDVi0hTJ5dnjcOA31bhUUXpxVFZHm2eKQTsPnMlzR3UiQvX5DTGuzOA 5oWawXIU1zO/d0O3ApHZQoPWgEsDOn1ozZOwWRSBtFeGFSTO5or1oJYjnZLBtLtXWWgm ldzA== X-Gm-Message-State: ABuFfoiPQtfSLFKdr0AV/LBsI4p97DlLSdoLpk0BgOp5jRw/3mZF7UNC RVgkGjZpWUV7BgdCeTtFPkg= X-Google-Smtp-Source: ACcGV61tUXkqhIvVkk0xcphQv4qcCyH2ETQVY+U/64gIVrf8pa9BheUeRLioHiTZX1DIMyMkptCkYA== X-Received: by 2002:a62:1407:: with SMTP id 7-v6mr36412739pfu.28.1539220655558; Wed, 10 Oct 2018 18:17:35 -0700 (PDT) Received: from localhost ([175.223.17.147]) by smtp.gmail.com with ESMTPSA id g6-v6sm38234391pgf.33.2018.10.10.18.17.33 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 10 Oct 2018 18:17:34 -0700 (PDT) Date: Thu, 11 Oct 2018 10:17:30 +0900 From: Sergey Senozhatsky To: Tetsuo Handa Cc: Dmitry Vyukov , Michal Hocko , Sergey Senozhatsky , syzbot , Johannes Weiner , Andrew Morton , guro@fb.com, "Kirill A. Shutemov" , LKML , Linux-MM , David Rientjes , syzkaller-bugs , Yang Shi , Sergey Senozhatsky , Petr Mladek Subject: Re: INFO: rcu detected stall in shmem_fault Message-ID: <20181011011730.GA728@jagdpanzerIV> References: <000000000000dc48d40577d4a587@google.com> <201810100012.w9A0Cjtn047782@www262.sakura.ne.jp> <20181010085945.GC5873@dhcp22.suse.cz> <20181010113500.GH5873@dhcp22.suse.cz> <20181010114833.GB3949@tigerII.localdomain> <20181010122539.GI5873@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (10/10/18 22:10), Tetsuo Handa wrote: > >> I've found at least 1 place that uses DEFAULT_RATELIMIT_INTERVAL*10: > >> https://elixir.bootlin.com/linux/latest/source/fs/btrfs/extent-tree.c#L8365 > >> Probably we need something similar here. > > Since printk() is a significantly CPU consuming operation, I think that what > we need to guarantee is interval between the end of an OOM killer messages > and the beginning of next OOM killer messages is large enough. For example, > setup a timer with 5 seconds timeout upon the end of an OOM killer messages > and check whether the timer already fired upon the beginning of next OOM killer > messages. Hmm, there is no way to make sure that previous OOM report made it to consoles. So maybe timer approach will be as good as rate-limiting. -ss