Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762744AbZAGXLn (ORCPT ); Wed, 7 Jan 2009 18:11:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755408AbZAGXLb (ORCPT ); Wed, 7 Jan 2009 18:11:31 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:34286 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752389AbZAGXLa (ORCPT ); Wed, 7 Jan 2009 18:11:30 -0500 Date: Wed, 7 Jan 2009 15:10:27 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Peter Zijlstra cc: Steven Rostedt , 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: <1231366716.11687.377.camel@twins> Message-ID: References: <87r63ljzox.fsf@basil.nowhere.org> <20090103191706.GA2002@parisc-linux.org> <4963584A.4090805@novell.com> <20090106131643.GA15228@elte.hu> <1231248041.11687.107.camel@twins> <49636799.1010109@novell.com> <20090106214229.GD6741@linux.vnet.ibm.com> <1231278275.11687.111.camel@twins> <1231279660.11687.121.camel@twins> <1231281801.11687.125.camel@twins> <1231283778.11687.136.camel@twins> <1231329783.11687.287.camel@twins> <1231347442.11687.344.camel@twins> <1231365115.11687.361.camel@twins> <1231366716.11687.377.camel@twins> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) 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: 773 Lines: 21 On Wed, 7 Jan 2009, Peter Zijlstra wrote: > > Hmm, still wouldn't the spin_on_owner() loopyness and the above need > that need_resched() check you mentioned to that it can fall into the > slow path and go to sleep? Yes, I do think that the outer loop at least should have a test for need_resched(). Please take all my patches to be pseudo-code. They've neither been compiled nor tested, and I'm just posting them in the hope that somebody else will then do things in the direction I think is the proper one ;) Linus -- 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/