Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752569AbaBBWDI (ORCPT ); Sun, 2 Feb 2014 17:03:08 -0500 Received: from e33.co.us.ibm.com ([32.97.110.151]:46891 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752462AbaBBWDF (ORCPT ); Sun, 2 Feb 2014 17:03:05 -0500 Date: Sun, 2 Feb 2014 14:02:58 -0800 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Jason Low , Ingo Molnar , Waiman Long , Linus Torvalds , Thomas Gleixner , Linux Kernel Mailing List , Rik van Riel , Andrew Morton , Davidlohr Bueso , "H. Peter Anvin" , Andi Kleen , "Chandramouleeswaran, Aswin" , "Norton, Scott J" , chegu_vinod@hp.com Subject: Re: [RFC][PATCH v2 5/5] mutex: Give spinners a chance to spin_on_owner if need_resched() triggered while queued Message-ID: <20140202220258.GF4333@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1390936396-3962-1-git-send-email-jason.low2@hp.com> <1390936396-3962-6-git-send-email-jason.low2@hp.com> <20140128210753.GJ11314@laptop.programming.kicks-ass.net> <1390949495.2807.52.camel@j-VirtualBox> <20140129115142.GE9636@twins.programming.kicks-ass.net> <1391138977.6284.82.camel@j-VirtualBox> <20140131140941.GF4941@twins.programming.kicks-ass.net> <20140131200825.GS5002@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140131200825.GS5002@laptop.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14020222-0928-0000-0000-000005ED9269 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 31, 2014 at 09:08:25PM +0100, Peter Zijlstra wrote: > On Fri, Jan 31, 2014 at 12:01:37PM -0800, Jason Low wrote: > > On Fri, Jan 31, 2014 at 6:09 AM, Peter Zijlstra wrote: > > > > > I've downloaded AIM7 from sf.net and I hope I'm running it with 100+ > > > loads but I'm not entirely sure I got this thing right, its not really > > > making progress with or without patch :/ > > > > Ingo's program http://lkml.org/lkml/2006/1/8/50 using the V option may > > be able to generate similar mutex contention. > > > > Currently still getting soft lockups with the updated version. > > Bugger.. ok clearly I need to think harder still. I'm fairly sure this > cancelation can work though, just seems tricky to get right :-) We used to do something similar to avoid passing locks off to tasks that had been interrupted while spinning, and it was a bit tricky. But we had it a bit easier, because we didn't actually have to remove the element from the queue, just bypass it at lock-grant time. Thanx, Paul > I'll give that proglet from Ingo a go, although that might be Monday ere > I get to it. > -- 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/