From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx143.postini.com [74.125.245.143]) by kanga.kvack.org (Postfix) with SMTP id BF9B56B13F0 for ; Thu, 2 Feb 2012 10:35:09 -0500 (EST) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 2 Feb 2012 08:35:08 -0700 Received: from d03relay03.boulder.ibm.com (d03relay03.boulder.ibm.com [9.17.195.228]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 907D63E40036 for ; Thu, 2 Feb 2012 08:34:49 -0700 (MST) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q12FYhdL098494 for ; Thu, 2 Feb 2012 08:34:45 -0700 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q12FYeij011401 for ; Thu, 2 Feb 2012 08:34:42 -0700 Date: Thu, 2 Feb 2012 07:34:37 -0800 From: "Paul E. McKenney" Subject: Re: [v7 0/8] Reduce cross CPU IPI interference Message-ID: <20120202153437.GD2518@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1327572121-13673-1-git-send-email-gilad@benyossef.com> <1327591185.2446.102.camel@twins> <1328117722.2446.262.camel@twins> <20120201184045.GG2382@linux.vnet.ibm.com> <20120201201336.GI2382@linux.vnet.ibm.com> <4F2A58A1.90800@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F2A58A1.90800@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Avi Kivity Cc: Christoph Lameter , Peter Zijlstra , Gilad Ben-Yossef , linux-kernel@vger.kernel.org, Chris Metcalf , Frederic Weisbecker , linux-mm@kvack.org, Pekka Enberg , Matt Mackall , Sasha Levin , Rik van Riel , Andi Kleen , Mel Gorman , Andrew Morton , Alexander Viro , Michal Nazarewicz , Kosaki Motohiro , Milton Miller On Thu, Feb 02, 2012 at 11:34:25AM +0200, Avi Kivity wrote: > On 02/01/2012 10:13 PM, Paul E. McKenney wrote: > > > > > > Could we also apply the same approach to processors busy doing > > > computational work? In that case the OS is also not needed. Interrupting > > > these activities is impacting on performance and latency. > > > > Yep, that is in fact what Frederic's dyntick-idle userspace work does. > > Running in a guest is a special case of running in userspace, so we'd > need to extend this work to kvm as well. As long as rcu_idle_enter() is called at the appropriate time, RCU will happily ignore the CPU. ;-) Thanx, Paul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org