From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753233Ab1LUKoB (ORCPT ); Wed, 21 Dec 2011 05:44:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2382 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751390Ab1LUKn7 (ORCPT ); Wed, 21 Dec 2011 05:43:59 -0500 Message-ID: <4EF1B85F.7060105@redhat.com> Date: Wed, 21 Dec 2011 12:43:43 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111115 Thunderbird/8.0 MIME-Version: 1.0 To: Nikunj A Dadhania CC: Ingo Molnar , peterz@infradead.org, linux-kernel@vger.kernel.org, vatsa@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com Subject: Re: [RFC PATCH 0/4] Gang scheduling in CFS References: <20111219083141.32311.9429.stgit@abhimanyu.in.ibm.com> <20111219112326.GA15090@elte.hu> <87sjke1a53.fsf@abhimanyu.in.ibm.com> In-Reply-To: <87sjke1a53.fsf@abhimanyu.in.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/21/2011 12:39 PM, Nikunj A Dadhania wrote: > On Mon, 19 Dec 2011 12:23:26 +0100, Ingo Molnar wrote: > > > > * Nikunj A. Dadhania wrote: > > > > So could we please approach this from the benchmarked workload > > angle first? The highest improvement is in ebizzy: > > > > > ebizzy 2vm (improved 15 times, i.e. 1520%) > > > > What's behind this huge speedup? Does ebizzy use user-space > > spinlocks perhaps? Could we do something on the user-space side > > to get a similar speedup? > > > This is from the perf run on the host: > > Baseline: > > 16.22% qemu-kvm [kvm_intel] [k] free_kvm_area > 8.27% qemu-kvm [kvm] [k] start_apic_timer > 7.53% qemu-kvm [kvm] [k] kvm_put_guest_fpu > > Gang: > > 24.44% qemu-kvm [kvm_intel] [k] free_kvm_area > 13.42% qemu-kvm [kvm] [k] start_apic_timer > 9.91% qemu-kvm [kvm] [k] kvm_put_guest_fpu > > Ingo, Avi, I am not getting anything obvious from this. Any ideas? > Looks like perf is confused, this sometimes happens if you rebuild the kernel but only rmmod/insmod kvm. Try a clean build + boot. -- error compiling committee.c: too many arguments to function