Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751066Ab3JWEmO (ORCPT ); Wed, 23 Oct 2013 00:42:14 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:44293 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750820Ab3JWEmN (ORCPT ); Wed, 23 Oct 2013 00:42:13 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: David Miller Cc: fengguang.wu@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20131022214129.GB2715@localhost> <20131022.180023.1141845387743361648.davem@davemloft.net> Date: Tue, 22 Oct 2013 21:38:10 -0700 In-Reply-To: <20131022.180023.1141845387743361648.davem@davemloft.net> (David Miller's message of "Tue, 22 Oct 2013 18:00:23 -0400 (EDT)") Message-ID: <87k3h461ql.fsf@tw-ebiederman.twitter.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX199KVyX5Dv60hNYeJHX3wyuUIedHgWtntQ= X-SA-Exim-Connect-IP: 8.25.197.25 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0073] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.4 XMBrknScrpt_02 Possible Broken Spam Script X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;David Miller X-Spam-Relay-Country: Subject: Re: -27% netperf TCP_STREAM regression by "tcp_memcontrol: Kill struct tcp_memcontrol" X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 14:26:46 -0700) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1428 Lines: 40 David Miller writes: > From: fengguang.wu@intel.com > Date: Tue, 22 Oct 2013 22:41:29 +0100 > >> We noticed big netperf throughput regressions >> >> a4fe34bf902b8f709c63 2e685cad57906e19add7 >> ------------------------ ------------------------ >> 707.40 -40.7% 419.60 lkp-nex04/micro/netperf/120s-200%-TCP_STREAM >> 2775.60 -23.7% 2116.40 lkp-sb03/micro/netperf/120s-200%-TCP_STREAM >> 3483.00 -27.2% 2536.00 TOTAL netperf.Throughput_Mbps >> >> and bisected it to >> >> commit 2e685cad57906e19add7189b5ff49dfb6aaa21d3 >> Author: Eric W. Biederman >> Date: Sat Oct 19 16:26:19 2013 -0700 >> >> tcp_memcontrol: Kill struct tcp_memcontrol > > Eric please look into this, I'd rather have a fix to apply than revert your > work. Will do I expect some ordering changed, and that changed the cache line behavior. If I can't find anything we can revert this one particular patch without affecting anything else, but it would be nice to keep the data structure smaller. Fengguag what would I need to do to reproduce this? Eric -- 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/