From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756606Ab0DACEA (ORCPT ); Wed, 31 Mar 2010 22:04:00 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:48093 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756146Ab0DACD5 (ORCPT ); Wed, 31 Mar 2010 22:03:57 -0400 Message-ID: <4BB3FF03.7060400@us.ibm.com> Date: Wed, 31 Mar 2010 19:03:47 -0700 From: Darren Hart User-Agent: Thunderbird 2.0.0.24 (X11/20100317) MIME-Version: 1.0 To: Roland Dreier CC: "lkml\, " , Steven Rostedt , Peter Zijlstra , Gregory Haskins , Sven-Thorsten Dietrich , Peter Morreale , Chris Wright , Thomas Gleixner , Ingo Molnar , Eric Dumazet Subject: Re: RFC: Ideal Adaptive Spinning Conditions References: <4BB3D90C.3030108@us.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Roland Dreier wrote: > > I'm looking at some adaptive spinning with futexes as a way to help > > reduce the dependence on sched_yield() to implement userspace > > spinlocks. Chris, I included you in the CC after reading your comments > > regarding sched_yield() at kernel summit and I thought you might be > > interested. > > I think you may have the wrong Chris. Chris Wright wasn't at the most > recent kernel summit and I do have a vague recollection of Chris Mason > mentioning that Oracle developers found that sched_yield() performed > better than futexes + kernel scheduling. Oh bother, Sorry Chris! I even talked to Chris Wright about this already in person and he told me I probably was looking for Chris Mason, and I still got the last names crossed up! -- Darren Hart IBM Linux Technology Center Real-Time Linux Team