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 C493DC4332F for ; Tue, 15 Nov 2022 12:05:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238189AbiKOMFf (ORCPT ); Tue, 15 Nov 2022 07:05:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbiKOMFT (ORCPT ); Tue, 15 Nov 2022 07:05:19 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92F932A40A for ; Tue, 15 Nov 2022 04:04:09 -0800 (PST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 47F841F8B4; Tue, 15 Nov 2022 12:04:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1668513848; 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=+mTdx5tg8Vlb5kyyqIvIDOY2WmPbB58ejrxB5NVI5nU=; b=OwOe6haAqMyswC05P6lNgDn5ghV3Sj2mqcfDD54l+/94vbCrSOX6YgbrrBDy+i9h7H6bTQ 6oxGri8m6pjnbd3zVqrefCdkOB7E8BHRzvoAqu5Vn9fHAMrHhN9o/LSPF6nPq5pf4xgyiZ 4iUaJeOp3t/ftXWLtGfccvyv9C7CKeM= 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 279DD2C143; Tue, 15 Nov 2022 12:04:08 +0000 (UTC) Date: Tue, 15 Nov 2022 13:04:07 +0100 From: Petr Mladek To: John Ogness Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH printk v4 05/39] printk: fix setting first seq for consoles Message-ID: References: <20221114162932.141883-1-john.ogness@linutronix.de> <20221114162932.141883-6-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221114162932.141883-6-john.ogness@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2022-11-14 17:34:58, 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