Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758640AbZAHCd6 (ORCPT ); Wed, 7 Jan 2009 21:33:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753796AbZAHCdh (ORCPT ); Wed, 7 Jan 2009 21:33:37 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:37101 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758219AbZAHCdf (ORCPT ); Wed, 7 Jan 2009 21:33:35 -0500 Date: Wed, 7 Jan 2009 21:33:31 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Linus Torvalds cc: Dave Kleikamp , Peter Zijlstra , paulmck@linux.vnet.ibm.com, Gregory Haskins , Ingo Molnar , Matthew Wilcox , Andi Kleen , Chris Mason , Andrew Morton , Linux Kernel Mailing List , linux-fsdevel , linux-btrfs , Thomas Gleixner , Nick Piggin , Peter Morreale , Sven Dietrich Subject: Re: [PATCH -v5][RFC]: mutex: implement adaptive spinning In-Reply-To: Message-ID: References: <87r63ljzox.fsf@basil.nowhere.org> <20090103191706.GA2002@parisc-linux.org> <1231368870.6686.16.camel@norville.austin.ibm.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 898 Lines: 22 On Wed, 7 Jan 2009, Linus Torvalds wrote: > > Should that be: > > > > #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_MEMORY_HOTPLUG) > > Well, probably CONFIG_MEMORY_HOTREMOVE, no? And I'd actually suggest that > unplugging should have a stop-machine if it doesn't already, just because > it's such a special case - like module removal. I do not think stop-machine will help, unless that spinning is protected by preempt-disable. If the task gets preempted after grabbing the owner thread_info, and then stop-machine runs, the memory disappears, the task is scheduled back, accesses the owner thread_info and then page-fault. -- Steve -- 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/