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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A807CC5479D for ; Mon, 9 Jan 2023 14:12:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236133AbjAIOMv (ORCPT ); Mon, 9 Jan 2023 09:12:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234657AbjAIOMq (ORCPT ); Mon, 9 Jan 2023 09:12:46 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D214BD111 for ; Mon, 9 Jan 2023 06:12:44 -0800 (PST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 665EB3EBF6; Mon, 9 Jan 2023 14:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1673273563; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+yozOgNTt9eCwnTHnsCOLaR7QkUN+VaDLEjV1bjk4IE=; b=UhANe2aAaTQOvENX8gBGQwv8p1pGCMBf/Dtx+ZItfP7CzK8+NDts2zZUsAUCkGKpDQo9Ha nme2ZxInNghp9YayRSwHpzS2z9sVn/S8JumEthckPD+2dPfr900itQ0RdC4pCyNPnxiYpk fqA8IOTjc8AMwjsAiebF8XDs8eRQbxg= Received: from suse.cz (unknown [10.100.208.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 351DA2C141; Mon, 9 Jan 2023 14:12:43 +0000 (UTC) Date: Mon, 9 Jan 2023 15:12:40 +0100 From: Petr Mladek To: John Ogness Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH printk v5 6/8] printk: introduce console_prepend_dropped() for dropped messages Message-ID: References: <20230109100800.1085541-1-john.ogness@linutronix.de> <20230109100800.1085541-7-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230109100800.1085541-7-john.ogness@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2023-01-09 11:13:58, John Ogness wrote: > Currently "dropped messages" are separately printed immediately > before printing the printk message. Since normal consoles are > now using an output buffer that is much larger than previously, > the "dropped message" could be prepended to the printk message > and then output everything in a single write() call. > > Introduce a helper function console_prepend_dropped() to prepend > an existing message with a "dropped message". This simplifies > the code by allowing all message formatting to be handled > together and then only requires a single write() call to output > the full message. And since this helper does not require any > locking, it can be used in the future for other console printing > contexts as well. > > Note that console_prepend_dropped() is defined as a NOP for > !CONFIG_PRINTK. Although the function will never be called for > !CONFIG_PRINTK, compiling the function can lead to warnings of > "always true" conditionals due to the size macro values used > in !CONFIG_PRINTK. > > Signed-off-by: John Ogness Reviewed-by: Petr Mladek Best Regards, Petr