From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raghavendra K T Subject: Re: Hack bench regression with CONFIG_SLUB_CPU_PARTIAL disabled (info only) Date: Thu, 25 Jul 2013 18:50:58 +0530 Message-ID: <51F1263A.6070704@linux.vnet.ibm.com> References: <51F0DB11.2080508@linux.vnet.ibm.com> <1374750359.23313.17.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , "Eric W. Biederman" , Eric Dumazet , Al Viro , Gao feng To: Eric Dumazet Return-path: Received: from e23smtp06.au.ibm.com ([202.81.31.148]:52171 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755618Ab3GYNNr (ORCPT ); Thu, 25 Jul 2013 09:13:47 -0400 Received: from /spool/local by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 25 Jul 2013 23:05:53 +1000 In-Reply-To: <1374750359.23313.17.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On 07/25/2013 04:35 PM, Eric Dumazet wrote: > On Thu, 2013-07-25 at 13:30 +0530, Raghavendra K T wrote: >> Hi, >> >> While testing hackbench with 3.11-rc1 I observed hackbench testcase >> took too long to complete (32 vcpu kvm guest on 32 core HT off machine). >> >> hackbench 1x degraded by 3 time (40sec vs 112sec) >> hackbench 2x degraded by around 20time (90sec vs 1800 sec) >> >> When I bisected, I found that I had CONFIG_SLUB_CPU_PARTIAL >> accidentally disabled. >> I understand that CONFIG_SLUB_CPU_PARTIAL=y by default and the config >> option is to provide determinism for RT kernels and thus it is not a >> problem. >> But thought of sharing this here so that if somebody runs into same >> issue accidently, it would save their time. > > Incidentally, what difference do you currently get with SLUB and SLAB ? > tested now, hackbench 1x is almost 2 times slower (40 vs 93) hackbench 2x is almost 6times slower (90sec vs 528)