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 DB17AC4332F for ; Tue, 8 Nov 2022 12:20:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234149AbiKHMUH (ORCPT ); Tue, 8 Nov 2022 07:20:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233763AbiKHMUF (ORCPT ); Tue, 8 Nov 2022 07:20:05 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57ECA13EBE for ; Tue, 8 Nov 2022 04:20:04 -0800 (PST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 0721D22496; Tue, 8 Nov 2022 12:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1667910003; 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=i1ez2b6nAQxv47XY59j1FdNBLhiUKsk/XyDIZANCyJ8=; b=d4559rvDxPe5Htwb6TY0SZPRJzbDJuF5S010XBtRDy6EcdS2Ql7YhZo3cygnXWixx9hV63 OCkn2gKJtdQd2kn5L1Hvw3P4AehroWYfwfY6jtj1ZFUgdNwF8kllf8LFjaeIkVSpTf3dNX S5fHX+FTg2wWTt+jd7o0scnSnSt/nvw= 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 DD5C82C142; Tue, 8 Nov 2022 12:20:02 +0000 (UTC) Date: Tue, 8 Nov 2022 13:20:02 +0100 From: Petr Mladek To: John Ogness Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH printk v3 05/40] printk: fix setting first seq for consoles Message-ID: References: <20221107141638.3790965-1-john.ogness@linutronix.de> <20221107141638.3790965-6-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221107141638.3790965-6-john.ogness@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2022-11-07 15:22:03, John Ogness wrote: > It used to be that all consoles were synchronized with respect to > which message they were printing. After commit a699449bb13b ("printk: > refactor and rework printing logic"), all consoles have their own > @seq for tracking which message they are on. That commit also changed > how the initial sequence number was chosen. Instead of choosing the > next non-printed message, it chose the sequence number of the next > message that will be added to the ringbuffer. > > That change created a possibility that a non-boot console taking over > for a boot console might skip messages if the boot console was behind > and did not have a chance to catch up before being unregistered. > > Since it is not possible to know which boot console a console is > taking over, use the lowest @seq of all the enabled boot consoles. If > no boot consoles are available/enabled, begin with the next message > that will be added to the ringbuffer. > > Also, since boot consoles are meant to be used at boot time, handle > them the same as CON_PRINTBUFFER to ensure that no initial messages > are skipped. > > Signed-off-by: John Ogness Reviewed-by: Petr Mladek Best Regards, Petr