From patchwork Thu Jan 26 22:54:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Helgaas X-Patchwork-Id: 48949 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp530557wrn; Thu, 26 Jan 2023 15:01:06 -0800 (PST) X-Google-Smtp-Source: AK7set9eMwvWhliB5ws5T/1jhpPScHt5ghaB3CrDt5mQv9auJ8aP7LMyDL3RaCoW36KIln3KuK+d X-Received: by 2002:a17:906:b310:b0:878:52cd:9006 with SMTP id n16-20020a170906b31000b0087852cd9006mr4917999ejz.69.1674774066059; Thu, 26 Jan 2023 15:01:06 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674774066; cv=none; d=google.com; s=arc-20160816; b=oSaVSULkgzkba+2zmzk01eV/kcCMtky8Fo4kjtwaIVE1/cvca9HwIzbRs1jKz3xbl0 KNTeq9laAneJUgzkISZt0ymVDVpo77BYShw2UvW+8apeWrimqbqpPndvcoZNuOMcxAtW 9I0+2j3gPnsjtSv57k4Sh6vy5BTO9d0p3dlRNx+91sHfVNat/L2w+STGaX3gxn5GQqQv +sM7ABJ1S7iCrsOPUs965rnLZu49PQPykPNCbfFX49G8s0QWSJlHwknfXWuyPBpvVHmf 9SC1TM9pdGUT0kLIFhKcz4fQ5A3r5qvvplR0WcuJzhfKeELxcnoUbPi9T8DyYSpA61oG ZVkg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=LR2kJ7SOwx/yhsThA+84QoEzVanCZH/r890YL/EqgMY=; b=hpcwRNqu7+e9kMgj6SIWx9lrRCF+p8Hl3Jj83BM+hTO92F5TN5B/NQH/H/Lo0ZDFYU M3QGd4Uqx7/RfCc1G4ERKZv74u04sAJ7QgCXytKlEOOX+rfBe0K51mi5i0+xlbJGYF0F qimm9WIgoYnlHgH2v9FOz2yNV7NFuJSZL6EDIi7qhVP1E58cQ/E+ZIb8zDHcBSkKBUus 33Rp0XcPulKc0Ayp4jBgPGLzCLwQZWHqYn0stQcJ3XUEj6GnznuSb0kGyy/+deBoh5g5 styRZ4DPqgvoBiiqbUeOwH/b3MnNOnXHzCH5JOsDL9TSwSrV/hg/lQYhjI9v+qgWBtO/ ywow== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="otj/1MSr"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ew18-20020a170907951200b0078315844537si2598496ejc.378.2023.01.26.15.00.42; Thu, 26 Jan 2023 15:01:06 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="otj/1MSr"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232740AbjAZWyq (ORCPT + 99 others); Thu, 26 Jan 2023 17:54:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233054AbjAZWye (ORCPT ); Thu, 26 Jan 2023 17:54:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A8AA7AA8; Thu, 26 Jan 2023 14:54:30 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DF00CB81C5E; Thu, 26 Jan 2023 22:54:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66A2AC433D2; Thu, 26 Jan 2023 22:54:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674773667; bh=A3hJdPRvqNFhvIc040dVHaOyGrcDglgpuQvKqvik2wo=; h=From:To:Cc:Subject:Date:From; b=otj/1MSrw0yysqoNbGEuXeqQMozGhrSqIB9eZlrYgbsXb4hIJbrZMzmFR7/RnYlIQ u5V34KfTKJG9ucf79p0W1+TlGqcCdMG11D1PJxtMXKq3CVYLrD/jxEyVpzZq736mSn D240LUTOUZRvQW1B4b15LN0zrhZoVckt9GfvmDGiIvBCO2AIrqZZOoLIuyF6Cri+8K phI/LbAbDN9O2VSUNn8vSqwMpux/0Fo48+4Gk80UfKowbTCeDINM1rwX7PA3TWGMoz uLixwzi5EQJL6KJSG8Kl6wJ6p0mjzZ/mjg99bBrEaEc6CgkgIi+gQ2K9hdgpf9Ilkw BB5Z8mFI1EN9A== From: Bjorn Helgaas To: Jonathan Corbet Cc: Matthew Wilcox , Randy Dunlap , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: [PATCH v2] printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay= Date: Thu, 26 Jan 2023 16:54:20 -0600 Message-Id: <20230126225420.1320276-1-helgaas@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756127890681652110?= X-GMAIL-MSGID: =?utf-8?q?1756127890681652110?= From: Bjorn Helgaas Document the fact that CONFIG_BOOT_PRINTK_DELAY must be enabled for the "boot_delay" kernel parameter to work. Also mention that "lpj=" may be necessary. Signed-off-by: Bjorn Helgaas Reviewed-by: Randy Dunlap --- Changes from v1 (https://lore.kernel.org/all/20230123180440.901793-1-helgaas@kernel.org/): - Clarify use of "lpj=". Reword consequences of delay larger than 10000. Documentation/admin-guide/kernel-parameters.txt | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6cfa6e3996cf..814e58487239 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -480,8 +480,10 @@ See Documentation/block/cmdline-partition.rst boot_delay= Milliseconds to delay each printk during boot. - Values larger than 10 seconds (10000) are changed to - no delay (0). + Only works if CONFIG_BOOT_PRINTK_DELAY is enabled, + and you may also have to specify "lpj=". Boot_delay + values larger than 10 seconds (10000) are assumed + erroneous and ignored. Format: integer bootconfig [KNL]