Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755119Ab2JRMkR (ORCPT ); Thu, 18 Oct 2012 08:40:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14415 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754801Ab2JRMkP (ORCPT ); Thu, 18 Oct 2012 08:40:15 -0400 Message-ID: <507FF87C.2060708@redhat.com> Date: Thu, 18 Oct 2012 14:39:24 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Raghavendra K T CC: "Andrew M. Theurer" , Peter Zijlstra , Rik van Riel , "H. Peter Anvin" , Ingo Molnar , Marcelo Tosatti , Srikar , "Nikunj A. Dadhania" , KVM , Jiannan Ouyang , chegu vinod , LKML , Srivatsa Vaddagiri , Gleb Natapov , Andrew Jones Subject: Re: [PATCH RFC 1/2] kvm: Handle undercommitted guest case in PLE handler References: <20120921120000.27611.71321.sendpatchset@codeblue> <505C654B.2050106@redhat.com> <505CA2EB.7050403@linux.vnet.ibm.com> <50607F1F.2040704@redhat.com> <20121003122209.GA9076@linux.vnet.ibm.com> <506C7057.6000102@redhat.com> <506D69AB.7020400@linux.vnet.ibm.com> <506D83EE.2020303@redhat.com> <1349356038.14388.3.camel@twins> <506DA48C.8050200@redhat.com> <20121009185108.GA2549@linux.vnet.ibm.com> In-Reply-To: <20121009185108.GA2549@linux.vnet.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 Content-Length: 2434 Lines: 59 On 10/09/2012 08:51 PM, Raghavendra K T wrote: > Here is the summary: > We do get good benefit by increasing ple window. Though we don't > see good benefit for kernbench and sysbench, for ebizzy, we get huge > improvement for 1x scenario. (almost 2/3rd of ple disabled case). > > Let me know if you think we can increase the default ple_window > itself to 16k. > I think so, there is no point running with untuned defaults. > > I can respin the whole series including this default ple_window change. It can come as a separate patch. > > I also have the perf kvm top result for both ebizzy and kernbench. > I think they are in expected lines now. > > Improvements > ================ > > 16 core PLE machine with 16 vcpu guest > > base = 3.6.0-rc5 + ple handler optimization patches > base_pleopt_16k = base + ple_window = 16k > base_pleopt_32k = base + ple_window = 32k > base_pleopt_nople = base + ple_gap = 0 > kernbench, hackbench, sysbench (time in sec lower is better) > ebizzy (rec/sec higher is better) > > % improvements w.r.t base (ple_window = 4k) > ---------------+---------------+-----------------+-------------------+ > |base_pleopt_16k| base_pleopt_32k | base_pleopt_nople | > ---------------+---------------+-----------------+-------------------+ > kernbench_1x | 0.42371 | 1.15164 | 0.09320 | > kernbench_2x | -1.40981 | -17.48282 | -570.77053 | > ---------------+---------------+-----------------+-------------------+ > sysbench_1x | -0.92367 | 0.24241 | -0.27027 | > sysbench_2x | -2.22706 |-0.30896 | -1.27573 | > sysbench_3x | -0.75509 | 0.09444 | -2.97756 | > ---------------+---------------+-----------------+-------------------+ > ebizzy_1x | 54.99976 | 67.29460 | 74.14076 | > ebizzy_2x | -8.83386 |-27.38403 | -96.22066 | > ---------------+---------------+-----------------+-------------------+ So it seems we want dynamic PLE windows. As soon as we enter overcommit we need to decrease the window. -- error compiling committee.c: too many arguments to function -- 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/