From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: Performance regression on kernels 3.10 and newer Date: Thu, 14 Aug 2014 12:59:18 -0700 Message-ID: <53ED1516.6020801@hp.com> References: <53ECFDAB.5010701@intel.com> <1408041962.6804.31.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , netdev To: Eric Dumazet , Alexander Duyck Return-path: Received: from g2t1383g.austin.hp.com ([15.217.136.92]:41348 "EHLO g2t1383g.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753118AbaHNT7z (ORCPT ); Thu, 14 Aug 2014 15:59:55 -0400 Received: from g2t2352.austin.hp.com (g2t2352.austin.hp.com [15.217.128.51]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by g2t1383g.austin.hp.com (Postfix) with ESMTPS id 3115A4C98 for ; Thu, 14 Aug 2014 19:59:55 +0000 (UTC) In-Reply-To: <1408041962.6804.31.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On 08/14/2014 11:46 AM, Eric Dumazet wrote: > I believe you answered your own question : prequeue mode does not work > very well when one host has hundred of active TCP flows to one other. > > In real life, applications do not use prequeue, because nobody wants one > thread per flow. > > Each socket has its own dst now route cache was removed, but if your > netperf migrates cpu (and NUMA node), we do not detect the dst should be > re-created onto a different NUMA node. Presumably, the -T $i,$j option in Alex's netperf command lines will have bound netperf and netserver to a specific CPU where they will have remained. rick jones