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 1952BC64EB5 for ; Tue, 2 Oct 2018 02:39:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3FC8208AE 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="R/zzUTTo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D3FC8208AE 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 S1726882AbeJBJUC (ORCPT ); Tue, 2 Oct 2018 05:20:02 -0400 Received: from mail-io1-f68.google.com ([209.85.166.68]:41949 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726748AbeJBJUB (ORCPT ); Tue, 2 Oct 2018 05:20:01 -0400 Received: by mail-io1-f68.google.com with SMTP id q4-v6so590781iob.8 for ; Mon, 01 Oct 2018 19:39:09 -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=BPastX5rxgolCsxo1cZqs/8RTdInA/A4IVQNI1iEWho=; b=R/zzUTTo6d3MGVRUCJkaEfKvtAm1IJncakiS+Yz5NsHzw+3xYqERCScs4TmLiCWTPD +2V9/IHtvnBgISEnULbTezwD6Wu/dy4CLiXQ2J6v5N0FVAhPbqQFG7/AIxnHAq0/DU4W QcLpJL308ow0xKeelx5vFZq7ZcI0uuQVcqvOfpPxJOmQkeoZocITzNTue7fgVFlsVNdH 9SQQoKsRufdDNY0CAeayD8T/Lqna0Gs2qFMCqTJhzExwRI+XMSSm6WHSfUitMDNz6/Ol YKGHyH2wwkI27Qwyht8OVHk+3/Wk+K1/yku4mFI4gHQbsBUeOhpq/97x2Ped0350VcXG 9Y9w== 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=BPastX5rxgolCsxo1cZqs/8RTdInA/A4IVQNI1iEWho=; b=DFnQ1Y1AWL2ANcV5V9QVdo/A8GQcHfdCoPDfIXLM88wdp2BzbTGNAG/rfctZKzaknK bkjlgnWNzxrTx1feWG9mxbgZHD5sUd4hTeTKyk0W1pQD1BZvY5P5AEZJBJcWJjrNi02h jeVFXOTiK7v+ayz+RA61nxx8Buv0aKx5UQqLa1po0+Rh8wRoa8B8NMNNjTQBoLUYocfC ypKr9tZQ9xT1SqECOlcnPV5NiiKjoYoglL6ICVFs0/2ojYYnih4CWlruZffRTmY5fgOz H/XseAqAZ95gEdGoslJVdHTZ+FidTun0LPrVONEMm5ju+ZlPS5fVkdcy7veVXloJDNux d/RA== X-Gm-Message-State: ABuFfoilxLtsyh13bwbIM/rMc2XYJk1AMxEH7Xp2/EGeek/5qIn/lFbG hd5rmBeg3DsExt0ptguNPPM= X-Google-Smtp-Source: ACcGV62c6epA9k4d0Ra6G1XWWwxXk184jdXz/ocPQlGCPYE1Wwzdmc+YsE78+WuojGO3a9nawAPtUA== X-Received: by 2002:a62:6d02:: with SMTP id i2-v6mr14436880pfc.218.1538447948938; Mon, 01 Oct 2018 19:39:08 -0700 (PDT) Received: from localhost.localdomain ([39.7.19.27]) by smtp.gmail.com with ESMTPSA id v83-v6sm35902744pfa.103.2018.10.01.19.39.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Oct 2018 19:39:07 -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 3/3] printk: do not preliminary split up cont buffer Date: Tue, 2 Oct 2018 11:38:36 +0900 Message-Id: <20181002023836.4487-4-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 We have a proper 'overflow' check which tells us that we need to split up existing cont buffer in separate records: if (cont.len + len > sizeof(cont.buf)) cont_flush(); At the same time we also have one extra flush: "if cont buffer is 80% full then split it up" in cont_add(): if (cont.len > (sizeof(cont.buf) * 80) / 100) cont_flush(); This looks to be redundant, since the existing "overflow" check should work just fine, so remove this 80% check and wait for either a normal cont termination \n, for preliminary flush due to possible buffer overflow or for preliminary flush due to cont race. Signed-off-by: Sergey Senozhatsky --- kernel/printk/printk.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index aea37b7927dd..1856db8128c6 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1822,9 +1822,6 @@ static bool cont_add(int facility, int level, enum log_flags flags, const char * cont_flush(); } - if (cont.len > (sizeof(cont.buf) * 80) / 100) - cont_flush(); - return true; } -- 2.19.0