From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757654AbYENWPS (ORCPT ); Wed, 14 May 2008 18:15:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751604AbYENWPF (ORCPT ); Wed, 14 May 2008 18:15:05 -0400 Received: from smtp-out01.alice-dsl.net ([88.44.60.11]:42925 "EHLO smtp-out01.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751488AbYENWPE (ORCPT ); Wed, 14 May 2008 18:15:04 -0400 To: Alan Cox Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Peter Zijlstra , Thomas Gleixner , Alexander Viro Subject: Re: [announce] "kill the Big Kernel Lock (BKL)" tree From: Andi Kleen References: <20080514174955.GA515@elte.hu> <20080514224600.5bb5db5c@core> Date: Thu, 15 May 2008 00:15:02 +0200 In-Reply-To: <20080514224600.5bb5db5c@core> (Alan Cox's message of "Wed, 14 May 2008 22:46:00 +0100") Message-ID: <877idw7ct5.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 14 May 2008 22:08:02.0084 (UTC) FILETIME=[FA0A5E40:01C8B60E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox writes: > Out of amusement I took the watchdog drivers and started looking for > large cans of worms in the BKL drop arena. > > Here is a fun one for general discussion - right now driver probe > functions request resources. We have no ordering on the requests so we > have deadlocks if two drivers do resource requests for conflicting > resources in reverse order. What deadlocks? resource allocation normally doesn't block. So if there's a ordering issue one of them will fail and should bail out. That said if you have conflicting resources then failing is the correct behavior anyways. -Andi