From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755825Ab2ADOmO (ORCPT ); Wed, 4 Jan 2012 09:42:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46949 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755090Ab2ADOmN (ORCPT ); Wed, 4 Jan 2012 09:42:13 -0500 Message-ID: <4F046536.5080207@redhat.com> Date: Wed, 04 Jan 2012 16:41:58 +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: Rik van Riel , 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> <4EF1B85F.7060105@redhat.com> <877h1o9dp7.fsf@linux.vnet.ibm.com> <20111223103620.GD4749@elte.hu> <4EF701C7.9080907@redhat.com> <20111230095147.GA10543@elte.hu> <878vlu4bgh.fsf@linux.vnet.ibm.com> <87pqf5mqg4.fsf@abhimanyu.in.ibm.com> <4F017AD2.3090504@redhat.com> <87mxa3zqm1.fsf@abhimanyu.in.ibm.com> In-Reply-To: <87mxa3zqm1.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 01/04/2012 12:52 PM, Nikunj A Dadhania wrote: > On Mon, 02 Jan 2012 11:37:22 +0200, Avi Kivity wrote: > > On 12/31/2011 04:21 AM, Nikunj A Dadhania wrote: > > > > > > GangV2: > > > 27.45% ebizzy libc-2.12.so [.] __memcpy_ssse3_back > > > 12.12% ebizzy [kernel.kallsyms] [k] clear_page > > > 9.22% ebizzy [kernel.kallsyms] [k] __do_page_fault > > > 6.91% ebizzy [kernel.kallsyms] [k] flush_tlb_others_ipi > > > 4.06% ebizzy [kernel.kallsyms] [k] get_page_from_freelist > > > 4.04% ebizzy [kernel.kallsyms] [k] ____pagevec_lru_add > > > > > > GangBase: > > > 45.08% ebizzy [kernel.kallsyms] [k] flush_tlb_others_ipi > > > 15.38% ebizzy libc-2.12.so [.] __memcpy_ssse3_back > > > 7.00% ebizzy [kernel.kallsyms] [k] clear_page > > > 4.88% ebizzy [kernel.kallsyms] [k] __do_page_fault > > > > Looping in flush_tlb_others(). Rik, what trace an we run to find out > > why PLE directed yield isn't working as expected? > > > I tried some experiments by adding a pause_loop_exits stat in the > kvm_vpu_stat. (that's deprecated, we use tracepoints these days for stats) > Here are some observation related to Baseline-only(8vm case) > > | ple_gap=128 | ple_gap=64 | ple_gap=256 | ple_window=2048 > --------------+-------------+------------+-------------+---------------- > EbzyRecords/s | 2247.50 | 2132.75 | 2086.25 | 1835.62 > PauseExits | 7928154.00 | 6696342.00 | 7365999.00 | 50319582.00 > > With ple_window = 2048, PauseExits is more than 6times the default case So it looks like the default is optimal, at least wrt the cases you tested and your test workload. -- error compiling committee.c: too many arguments to function