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=-2.4 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 22087C07E85 for ; Fri, 7 Dec 2018 05:31:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDE3520700 for ; Fri, 7 Dec 2018 05:31:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UC7nvWAG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BDE3520700 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 S1725992AbeLGFbH (ORCPT ); Fri, 7 Dec 2018 00:31:07 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:37767 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbeLGFbH (ORCPT ); Fri, 7 Dec 2018 00:31:07 -0500 Received: by mail-pg1-f195.google.com with SMTP id 80so1204827pge.4 for ; Thu, 06 Dec 2018 21:31:06 -0800 (PST) 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=cce3TwqUc0Wx7yBu9QHQJba0mLC/z0FVKzj//GVZXzk=; b=UC7nvWAGdHWzTQ3UXWOUtYhXrv0f+x5ss2z+vMppuSFsxVfV8Ln65Xp7+QKtE5pbx8 0oXzexF0otpUf7gOZJkFDQq7oBcqd3eSp6kmijPlk1e09SRa4tOqRXEXHXVdntMZrNTm 6ATezVH+lJGhLGptU1EeYcwf/HEpDAEn/ItohxcfU6ZYVSpX3As5ckW6CU9AK8o4fyzl goJLCoJp58s8Y0HBfs9NvrSgoNwFTSoQQWZNPdkYzk3eWZzGPs80iUFmI6rbbGwe6c8/ whT4QcVTX4BykISWw2j3bgvKy8B74Sicu4+at5k53w8ouBf+0Eh1t1+fYtt9Jo2tfWFA Uznw== 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=cce3TwqUc0Wx7yBu9QHQJba0mLC/z0FVKzj//GVZXzk=; b=jNo4vkPYvE+c5qIwDDNnNdXPfp1pv81D6sceKFUtDflYEkfkUHG7y9gqivGJ5cZA0I WCPsV04+1KZv7hfggrk/++kZtFZjcxm6Qaa4q1PKZBJ4d3305RaQ5T61/nBlPpgDHJFT 3OXh+aCR5mdxqGvbpABDAbLNy79lzgFBeiVaxxpOHVy9htIRQXAaswHBlkWgLpdfpGSb MKb9/uhwbECTyJH8/AiRYNSgLLUdVeU+oJgkYuYtd2G2KBEeJsQxj/f2OWr7YU76RFmH H/V8WL2vbqSgDUHixZ9wbeEP5hXPgMcrvSgSZ5IjUInkGysdXs+i8RZp1aA6FHaz5qyr ohyQ== X-Gm-Message-State: AA+aEWbAmuvTSdo8FftcLo+22nMjrORJPo1mp7ZZVIUlRS1RYVrX8wnr zw+ks2k9lZMVorDC5SLvjUU= X-Google-Smtp-Source: AFSGD/X8HiJSj+4JX8qQN3dcZAe+kWCd/J52lWWSFeFsGMM1Gx2FFOy6NIBST0RgLIZtMmNYrJMdHg== X-Received: by 2002:a63:5407:: with SMTP id i7mr754477pgb.413.1544160666056; Thu, 06 Dec 2018 21:31:06 -0800 (PST) Received: from localhost ([175.223.11.40]) by smtp.gmail.com with ESMTPSA id y184sm2296733pgd.71.2018.12.06.21.31.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 06 Dec 2018 21:31:04 -0800 (PST) Date: Fri, 7 Dec 2018 14:31:01 +0900 From: Sergey Senozhatsky To: Tetsuo Handa Cc: Sergey Senozhatsky , Petr Mladek , Dmitry Vyukov , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Andrew Morton , LKML , syzkaller Subject: Re: [PATCH] printk: Add caller information to printk() output. Message-ID: <20181207053101.GA3729@jagdpanzerIV> References: <459018db-763b-9520-ead2-2c0d5975fbf3@i-love.sakura.ne.jp> <20181205115041.GB453@jagdpanzerIV> <201812070458.wB74wTYu074308@www262.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201812070458.wB74wTYu074308@www262.sakura.ne.jp> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (12/07/18 13:58), Tetsuo Handa wrote: > > All you need is a way to reconstruct a message around > > some very specific place in the log - say in a range [-500, +500] lines, > > assuming that a backtrace you are trying to reconstruct is badly fragmented. > > I think, even 3 lower digits of a PID should do the trick. > > 3 lower digits is insufficient for reconstructing PID of interest; it can > conflict at 1/1000 probability. OK. So you want to "trace" PID, not just a way to reconstruct fragmented backtraces in particular places of a serial log file; that's a different story. > [15.922239TABI/] e1000: ens32 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None > [15.923927TABYb] IPv6: ADDRCONF(NETDEV_UP): ens32: link is not ready > [15.930537TABI/] IPv6: ADDRCONF(NETDEV_CHANGE): ens32: link becomes ready > [40.506011CAAAA] random: crng init done > [926.716687TAAAB] reboot: Power down > ---------------------------------------- Please, no. PIDs, fixed size area, human readable. Just like Petr suggested. [ 123.12312][ T234] apic: boom -ss