Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964832AbVJZRLf (ORCPT ); Wed, 26 Oct 2005 13:11:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964833AbVJZRLf (ORCPT ); Wed, 26 Oct 2005 13:11:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:65240 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S964832AbVJZRLe convert rfc822-to-8bit (ORCPT ); Wed, 26 Oct 2005 13:11:34 -0400 Message-ID: <5600736.1130346691049.SLOX.WebMail.wwwrun@imap-dhs.suse.de> Date: Wed, 26 Oct 2005 19:11:31 +0200 (CEST) From: Andreas Kleen To: sekharan@us.ibm.com Subject: Re: Notifier chains are unsafe Cc: Alan Stern , linux-kernel@vger.kernel.org, dipankar@in.ibm.com In-Reply-To: <1130284911.3586.152.camel@linuxchandra> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-Priority: 3 (normal) X-Mailer: SuSE Linux Openexchange Server 4 - WebMail (Build 2.4160) X-Operating-System: Linux 2.4.21-295-smp i386 (JVM 1.3.1_13) Organization: SuSE Linux AG References: <1130284911.3586.152.camel@linuxchandra> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 790 Lines: 28 Am Mi 26.10.2005 02:01 schrieb Chandra Seetharaman : > > Better would be likely to use RCU. > > RCU will be a problem if the registered notifiers need to block.   Actually blocking should be ok, as long as the blocking notifier doesn't unregister itself. The current next pointer will be always reloaded after the blocking.   Still on preemptive kernels there might be problems, but they could be likely solved by a few strategic preempt_disables in notifier_call_chain().   Dipankar, what do you think?   -Andi     - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/