From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751786AbXCHNH3 (ORCPT ); Thu, 8 Mar 2007 08:07:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751795AbXCHNH3 (ORCPT ); Thu, 8 Mar 2007 08:07:29 -0500 Received: from postfix1-g20.free.fr ([212.27.60.42]:48345 "EHLO postfix1-g20.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751786AbXCHNH2 (ORCPT ); Thu, 8 Mar 2007 08:07:28 -0500 Date: Thu, 8 Mar 2007 14:06:08 +0100 From: Thibaut VARENE To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org Subject: [PATCH] make elv_register() output atomic Message-ID: <20070308140608.2b034013@Alucard.r3z0> Organization: PA/Linux X-Mailer: Sylpheed-Claws 2.6.0 (GTK+ 2.8.20; powerpc-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Booting 2.6.21-rc3-g45592145 I noticed the following on one of my machines in the bootlog: io scheduler noop registered<6>Time: jiffies clocksource has been installed. io scheduler deadline registered (default) Looking at block/elevator.c, it appears that elv_register() uses two consecutive printks in a non-atomic way, leading to the above glitch. The attached trivial patch fixes this issue, by using a single printk. HTH T-Bone PS: please CC-me in replies. Signed-off-by: Thibaut VARENE -- Thibaut VARENE http://www.parisc-linux.org/~varenet/ diff --git a/block/elevator.c b/block/elevator.c index 25f6ef2..96a00c8 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -964,17 +964,18 @@ void elv_unregister_queue(struct request_queue *q) int elv_register(struct elevator_type *e) { + char *def = ""; spin_lock_irq(&elv_list_lock); BUG_ON(elevator_find(e->elevator_name)); list_add_tail(&e->list, &elv_list); spin_unlock_irq(&elv_list_lock); - printk(KERN_INFO "io scheduler %s registered", e->elevator_name); if (!strcmp(e->elevator_name, chosen_elevator) || (!*chosen_elevator && !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) - printk(" (default)"); - printk("\n"); + def = " (default)"; + + printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def); return 0; } EXPORT_SYMBOL_GPL(elv_register);