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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 94D1FC00449 for ; Tue, 2 Oct 2018 02:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B76D208AE for ; Tue, 2 Oct 2018 02:39:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="MQCiVT1y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B76D208AE 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 S1726783AbeJBJTt (ORCPT ); Tue, 2 Oct 2018 05:19:49 -0400 Received: from mail-it1-f195.google.com ([209.85.166.195]:54164 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726748AbeJBJTt (ORCPT ); Tue, 2 Oct 2018 05:19:49 -0400 Received: by mail-it1-f195.google.com with SMTP id q70-v6so1358330itb.3 for ; Mon, 01 Oct 2018 19:38:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=a0stoVsAw0VRDll7xKIRYaZk/NNhRyx/JgJ4JBhyYBI=; b=MQCiVT1yBHZwhB1okfLL+82FvWp4GoO2TF0lo8c8BbIiB3TwHiwU1yv+AtrW74bum0 ZrH9D4NnR2Q7185gqVr03WF+df6ykmmjIgdLxz9ITQ98FUpqKDy+j1T64DOlDBIS3/ri dTx4U8A0+Bi3UOebtpHAGMsSHd0qiuQqWkeTU3J6HVXuT2XpKjiQQzhWQLgCZZscxhyN 07S5A5sdr3DDLUy4fxAWfGjQU1opQgqVZ61Jht7adcS4rLjFDW503bAgf+Jsm5Npco6n S//rTFy2nlO5BOBAearo71JbNKuXxKhqLPtUOR8oAqKkiBN8m+agSyy5iKXkQ1lDZ7pJ BZFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=a0stoVsAw0VRDll7xKIRYaZk/NNhRyx/JgJ4JBhyYBI=; b=DaU/qkHA4shURwjhFpBXPAu0gBZIwnXsN26p3Hc6v4tjtcATr2k57HhIdW9dwLDwqo koWd5MY0eXeREwwV5ZqSk5o4WerMnjsIrXZJ8DGT97DvSgSwRUiDnJCc9AZx9llqXSpk GFaE7jivGVvd/WohXU/q2MrZmlac6/ARo2hdPHUbn8k+eMO3aBqR+vKmq0MPY/OPQ0Kr AhAzPEgmnSND+vUmDg8qe9j4Z2xGWjvqGX97FzmDYaiMuQQXEa8P3NiCiAwA9T8Z3zVd i+eqRoCOEMRDoPo6OZLy4a7138Jn1bSc2yUhlCObglFf9GgDYE0UcsCComLEBM9yzA9k VpLQ== X-Gm-Message-State: ABuFfohHyEl73g79SFrvzwCNH0qnCYuBP3zpPX8OE6Fu/2/6zQe51qJQ 6Hm5c2UFekAkEWVGKgJxmZw= X-Google-Smtp-Source: ACcGV60vQ9D5L8UDYEI9Pq6eXE4BdCOmCN3VaFYhn5DAfU6p3EJlyUuCnfXG5Zoy4EM0CVlLbIm64g== X-Received: by 2002:a63:4f20:: with SMTP id d32-v6mr12278543pgb.231.1538447936479; Mon, 01 Oct 2018 19:38:56 -0700 (PDT) Received: from localhost.localdomain ([39.7.19.27]) by smtp.gmail.com with ESMTPSA id v83-v6sm35902744pfa.103.2018.10.01.19.38.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Oct 2018 19:38:55 -0700 (PDT) From: Sergey Senozhatsky X-Google-Original-From: Sergey Senozhatsky To: Steven Rostedt , Petr Mladek Cc: Andrew Morton , Dmitriy Vyukov , Tetsuo Handa , Tejun Heo , Peter Zijlstra , LKML , Sergey Senozhatsky , Sergey Senozhatsky Subject: [RFC][PATCH 1/3] printk: keep kernel cont support always enabled Date: Tue, 2 Oct 2018 11:38:34 +0900 Message-Id: <20181002023836.4487-2-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181002023836.4487-1-sergey.senozhatsky@gmail.com> References: <20181002023836.4487-1-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since 5c2992ee7fd8a29 ("printk: remove console flushing special cases for partial buffered lines") we don't print cont fragments to the consoles; cont lines are now proper log_buf entries and there is no "consecutive continuation flag" anymore: we either have 'c' entries that mark continuation lines without fragments; or '-' entries that mark normal logbuf entries. There are no '+' entries anymore. However, we still have a small leftover - presence of ext_console drivers disables kernel cont support and we flush each pr_cont() and store it as a separate log_buf entry. Previously, it worked because msg_print_ext_header() had that "an optional external merge of the records" functionality: if (msg->flags & LOG_CONT) cont = (prev_flags & LOG_CONT) ? '+' : 'c'; We don't do this as of now, so keep kernel cont always enabled. Signed-off-by: Sergey Senozhatsky --- kernel/printk/printk.c | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 308497194bd4..e72cb793aff1 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -192,16 +192,7 @@ int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, return 0; } -/* - * Number of registered extended console drivers. - * - * If extended consoles are present, in-kernel cont reassembly is disabled - * and each fragment is stored as a separate log entry with proper - * continuation flag so that every emitted message has full metadata. This - * doesn't change the result for regular consoles or /proc/kmsg. For - * /dev/kmsg, as long as the reader concatenates messages according to - * consecutive continuation flags, the end result should be the same too. - */ +/* Number of registered extended console drivers. */ static int nr_ext_console_drivers; /* @@ -1806,12 +1797,8 @@ static void cont_flush(void) static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len) { - /* - * If ext consoles are present, flush and skip in-kernel - * continuation. See nr_ext_console_drivers definition. Also, if - * the line gets too long, split it up in separate records. - */ - if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) { + /* If the line gets too long, split it up in separate records. */ + if (cont.len + len > sizeof(cont.buf)) { cont_flush(); return false; } @@ -2731,8 +2718,7 @@ void register_console(struct console *newcon) } if (newcon->flags & CON_EXTENDED) - if (!nr_ext_console_drivers++) - pr_info("printk: continuation disabled due to ext consoles, expect more fragments in /dev/kmsg\n"); + nr_ext_console_drivers++; if (newcon->flags & CON_PRINTBUFFER) { /* -- 2.19.0