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=-3.9 required=3.0 tests=BAYES_00, CHARSET_FARAWAY_HEADER,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 2A4B4C28E83 for ; Fri, 4 Sep 2020 09:31:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAF1A205CB for ; Fri, 4 Sep 2020 09:31:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="N8ICZD2o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730213AbgIDJbl (ORCPT ); Fri, 4 Sep 2020 05:31:41 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:37492 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730079AbgIDJbX (ORCPT ); Fri, 4 Sep 2020 05:31:23 -0400 Received: from epcas2p4.samsung.com (unknown [182.195.41.56]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20200904093120epoutp04d1633d13d25e05a567f32687b8f9fb59~xirtiCXEb0864508645epoutp04b for ; Fri, 4 Sep 2020 09:31:20 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20200904093120epoutp04d1633d13d25e05a567f32687b8f9fb59~xirtiCXEb0864508645epoutp04b DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1599211880; bh=7eKjrrXMyPcGGy+prk+NmLZfDzVLo+N1HJeKK1CMHe4=; h=From:To:Cc:In-Reply-To:Subject:Date:References:From; b=N8ICZD2ofRhxbkY6uMXozC9b8pcHFxQnc2a+t4phOSdGAZdULXKtCDdaiDqt4D2L7 NJ/FdNPIqrXcdVLg0Al1bomHGsJGy8xG6uach0z/I0TybQPZs8nRMp4ddDRF/Xxf2C kiiKrx/aL6urUraPH3tiSWfXmRcgeP01p4jksqr8= Received: from epsnrtp2.localdomain (unknown [182.195.42.163]) by epcas2p1.samsung.com (KnoxPortal) with ESMTP id 20200904093119epcas2p1c407462349b2029df1c237c1471639e2~xirsskAH53257332573epcas2p1o; Fri, 4 Sep 2020 09:31:19 +0000 (GMT) Received: from epsmges2p1.samsung.com (unknown [182.195.40.188]) by epsnrtp2.localdomain (Postfix) with ESMTP id 4BjXVY0YSKzMqYkk; Fri, 4 Sep 2020 09:31:17 +0000 (GMT) Received: from epcas2p4.samsung.com ( [182.195.41.56]) by epsmges2p1.samsung.com (Symantec Messaging Gateway) with SMTP id 7F.65.19322.269025F5; Fri, 4 Sep 2020 18:31:14 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas2p3.samsung.com (KnoxPortal) with ESMTPA id 20200904093114epcas2p36f311d20d3b7729bc965786c76f18ca1~xiroVHUUr2511625116epcas2p3q; Fri, 4 Sep 2020 09:31:14 +0000 (GMT) Received: from epsmgms1p2.samsung.com (unknown [182.195.42.42]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20200904093114epsmtrp1c64de14308dfb25465b57183c1bcac0d~xiroURU9a1961419614epsmtrp1X; Fri, 4 Sep 2020 09:31:14 +0000 (GMT) X-AuditID: b6c32a45-7adff70000004b7a-a9-5f5209626cd4 Received: from epsmtip1.samsung.com ( [182.195.34.30]) by epsmgms1p2.samsung.com (Symantec Messaging Gateway) with SMTP id 47.0A.08303.269025F5; Fri, 4 Sep 2020 18:31:14 +0900 (KST) Received: from KORDD001994 (unknown [12.36.185.71]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20200904093114epsmtip1d36b0b0c3b7c5c7200a14931c2e8fb37~xiroIHwxt0857908579epsmtip1B; Fri, 4 Sep 2020 09:31:14 +0000 (GMT) From: =?ks_c_5601-1987?B?sejDorHi?= To: "'Greg KH'" Cc: , , , , , , , In-Reply-To: <20200904090535.GA2440145@kroah.com> Subject: RE: printk: Add process name information to printk() output. Date: Fri, 4 Sep 2020 18:31:13 +0900 Message-ID: <000001d6829e$2226cc60$66746520$@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ks_c_5601-1987" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQMW8ccY1/AbwLmEvIpBmAjIk1luugFhZewlAjg6wOumuolUIA== Content-Language: ko X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDJsWRmVeSWpSXmKPExsWy7bCmhW4SZ1C8wdaTNhbNi9ezWWy7Mp/R 4vz5DewWl3fNYbN4+OAGq8X/x19ZLV5s7mS12NfxgMli7efH7A6cHjtn3WX3aNl3i91j06pO No93586xe+yfu4bdY/2WqywenzfJBbBH5dhkpCampBYppOYl56dk5qXbKnkHxzvHm5oZGOoa WlqYKynkJeam2iq5+AToumXmAJ2mpFCWmFMKFApILC5W0rezKcovLUlVyMgvLrFVSi1IySkw NCzQK07MLS7NS9dLzs+1MjQwMDIFqkzIydh/aQlzQRNvReeiN0wNjE85uxg5OSQETCR2T57L 3sXIxSEksINR4t/tzVDOJ0aJl98uskE4nxklzncsYYdpeXl6BitEYhejxNHD7cwQzgug/t+7 mUGq2ARsJdo7H4B1iAjoSHScOcECUsQscIFRouf7ZCaQBKeAocS7TfsZQWxhAVeJ1yffgTWw CKhIXNn9FmwQr4ClxISGeYwQtqDEyZlPWEBsZgEjiSWr5zNB2PIS29/OYYY4T0Hi59NlQOdx AC12krjf7AVRIiIxu7MNqmQLh8TvF8oQtovEjEXbWCFsYYlXx7dAfSkl8bK/Dcqul/jWvwDs fgmBHkaJv13H2SASxhKznrUzguySEFCWOHIL6jQ+iY7Df9khwrwSHW1CEKaqRPdkfQhTWuLD DpsJjEqzkLw1C8lbs5C8NQvJ/QsYWVYxiqUWFOempxYbFRgiR/YmRnCy1XLdwTj57Qe9Q4xM HIyHGCU4mJVEeD3OBcYL8aYkVlalFuXHF5XmpBYfYjQFhvREZinR5Hxgus8riTc0NTIzM7A0 tTA1M7JQEufNVbwQJySQnliSmp2aWpBaBNPHxMEp1cBUsEqL4d4a+8hmf4GElKPV3P/S1q1W VmRNY925pulcjnSKRJbq4kzGnp7EFct9xU7Pty6Km/fDRNE5/cVP5Vl8K26FfOSNurrLZaZU okfRlDtGU2bwqBbd/xKrsu++WWyJV9Kbj96hp34sfrq1K1h9sf+F7pKJjlzM+pczVe83Td+n cWHysewm4TsrLlQZivV/VrRRZyq3ib0RKXh7pxP7V+N5VkrJDWfP/E45f2/P1v9OszxEfq5J /Nn67fh83ivzb6y7z3viwF0RprKbPK1LNi12+i1oumEZf+I1/+2xGxI3+NZm9WdXdURYFvns ZS34sWeb08a3p5Z1Tw20ZKgx/Coltp2rS6JaTjycc6sSS3FGoqEWc1FxIgDa/2dwPwQAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprBIsWRmVeSWpSXmKPExsWy7bCSnG4SZ1C8wZKZkhbNi9ezWWy7Mp/R 4vz5DewWl3fNYbN4+OAGq8X/x19ZLV5s7mS12NfxgMli7efH7A6cHjtn3WX3aNl3i91j06pO No93586xe+yfu4bdY/2WqywenzfJBbBHcdmkpOZklqUW6dslcGXsv7SEuaCJt6Jz0RumBsan nF2MnBwSAiYSL0/PYO1i5OIQEtjBKLFy/g82iIS0xPFXs9khbGGJ+y1HoIqeMUp8ujqRGSTB JmAr0d75AKxIREBHouPMCRaQImaBW4wSKz48Yofo2MwosWbNRLAqTgFDiXeb9jOC2MICrhKv T74Di7MIqEhc2f0WbCqvgKXEhIZ5jBC2oMTJmU9YQGxmoFsbD3dD2fIS29/OYYY4T0Hi59Nl QOdxAF3hJHG/2QuiRERidmcb8wRG4VlIJs1CMmkWkkmzkLQsYGRZxSiZWlCcm55bbFhglJda rlecmFtcmpeul5yfu4kRHHlaWjsY96z6oHeIkYmD8RCjBAezkgivx7nAeCHelMTKqtSi/Pii 0pzU4kOM0hwsSuK8X2ctjBMSSE8sSc1OTS1ILYLJMnFwSjUwbX1pfjfqtmVZo6ZyVwfnaT6V kocp/u8OrT3Lk7OiJO9xQ0fBPNfYKz9LFqzvYWLYzdaYM8F9T5vZhddCZ0z7u0t2bOGYunf5 JIHZ0//utagx8Iz/yFojaPjITrhxwhsBw8Md118vC2fs/8jhv/uutcTB7QWnZh4Sa03PuH3d 4rjxxCWOinsSbogc7u1l7eK2EltQfuDuty3HNzhtj1q/ScXdSLGne5LJnrm5GbVxFycrnOjP vqvocu+tievV1T9WX/Gdc8hg/SbupzvUjsav+pdSIia8YKL5H5tDhw0nR9/YL8MQOMNyTdbp OLHd2nz3OcLTdvycsFKUV9eTKeTGOauN15wZv+9cabT1yg+J+0osxRmJhlrMRcWJAApa+msr AwAA X-CMS-MailID: 20200904093114epcas2p36f311d20d3b7729bc965786c76f18ca1 X-Msg-Generator: CA X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20200904082449epcas2p4420d5df2083325b328a182c79f5c0948 References: <20200904082438.20707-1-changki.kim@samsung.com> <20200904090535.GA2440145@kroah.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Fri, Sep 04, 2020 at 05:24:38PM +0900, Changki Kim wrote: > > Printk() meesages are the most basic and useful debug method. > > However, additional information needs in multi-processor. > > If we add messages with processor id and process name, we can find a > > problem only with messages when the problem occurs with H/W IP or CPU. > > This is very useful in narrowing down the scope of the problems. > > > > Therefore, instead of trying to help buffering, let's try to help > > reconstructing messages by saving caller information as of calling > > log_store() and adding it as "[$processor_id: $process_name: > $thread_id]" > > upon printing to consoles. > > > > Some examples for console output: > > > > [ 0.059580] [0: swapper/0: 1] CPU: All CPU(s) started at EL1i > > [ 2.153157] [5: init: 1] migov: complete to probe migov > > [ 7.441317] [4: init: 1] NET: Registered protocol family 39 > > [ 22.793389] [5: kworker/u16:1: 184] SMP: stopping secondary CPUs > > > > Signed-off-by: Changki Kim > > --- > > kernel/printk/printk.c | 20 ++++++++++++++++++-- > > kernel/printk/printk_ringbuffer.h | 7 +++++++ > > lib/Kconfig.debug | 16 ++++++++++++++++ > > 3 files changed, 41 insertions(+), 2 deletions(-) > > Isn't the CPU number already present if you want it today? Why add it > again? > > thanks, > > greg k-h CPU number isn't present now. If I enabled PRINTK_CALLER, then it is present cpu id or thread id. The config isn't always present cpu id. We need cpu id each each message. Thanks.