From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx175.postini.com [74.125.245.175]) by kanga.kvack.org (Postfix) with SMTP id 35F186B13F1 for ; Thu, 2 Feb 2012 12:53:23 -0500 (EST) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 2 Feb 2012 12:53:22 -0500 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 1AF7838C8056 for ; Thu, 2 Feb 2012 12:53:19 -0500 (EST) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q12Hpvf4265406 for ; Thu, 2 Feb 2012 12:51:59 -0500 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 q12Hpuv7017555 for ; Thu, 2 Feb 2012 10:51:57 -0700 Date: Thu, 2 Feb 2012 09:51:55 -0800 From: "Paul E. McKenney" Subject: Re: [v7 0/8] Reduce cross CPU IPI interference Message-ID: <20120202175155.GV2518@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1328117722.2446.262.camel@twins> <20120201184045.GG2382@linux.vnet.ibm.com> <20120201201336.GI2382@linux.vnet.ibm.com> <4F2A58A1.90800@redhat.com> <20120202153437.GD2518@linux.vnet.ibm.com> <4F2AB66C.2030309@redhat.com> <20120202170134.GM2518@linux.vnet.ibm.com> <4F2AC69B.7000704@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F2AC69B.7000704@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 07:23:39PM +0200, Avi Kivity wrote: > On 02/02/2012 07:01 PM, Paul E. McKenney wrote: > > > > > > It's not called (since the cpu is not idle). Instead we call > > > rcu_virt_note_context_switch(). > > > > Frederic's work checks to see if there is only one runnable user task > > on a given CPU. If there is only one, then the scheduling-clock interrupt > > is turned off for that CPU, and RCU is told to ignore it while it is > > executing in user space. Not sure whether this covers KVM guests. > > Conceptually it's the same. Maybe it needs adjustments, since kvm > enters a guest in a different way than the kernel exits to userspace. > > > In any case, this is not yet in mainline. > > Let me know when it's in, and I'll have a look. Could you please touch base with Frederic Weisbecker to make sure that what he is doing works for you? 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