From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Bligh Subject: Re: Testing interface removal speedup patches from Eric Dumazet. Date: Mon, 09 May 2011 19:56:22 +0100 Message-ID: <06627C760FB049F1A9321BC6@Ximines.local> References: <4DC83471.7030701@candelatech.com> Reply-To: Alex Bligh Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , Alex Bligh To: Ben Greear , netdev Return-path: Received: from mail.avalus.com ([89.16.176.221]:54770 "EHLO mail.avalus.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751933Ab1EIS4X (ORCPT ); Mon, 9 May 2011 14:56:23 -0400 In-Reply-To: <4DC83471.7030701@candelatech.com> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: --On 9 May 2011 11:37:37 -0700 Ben Greear wrote: With: > Created 500 veth in 17.874695 seconds (0.03574939 per interface). > Deleted 500 veth in 17.023607 seconds. (0.034047214 per interface) Without: > Created 500 veth in 22.507598 seconds (0.045015196 per interface). > Deleted 500 veth in 34.998733 seconds. (0.069997466 per interface) Interesting. On my tests (albeit with CONFIG_HZ=100) I got: 100 pairs 500 pairs Interface creation 14ms 110ms Interface deletion 160ms 148ms So Eric's patches help in the interface create case, even though there is no synchronize_net, sychronize_sched() or rcu_barrier() there. I had assumed the slow create (which varies by number of pairs) was down to sysfs scalability only (see difference between 14ms and 110ms there). Out of interest, if you still happen to have the scripts around, how fast is veth creation if you just do 100 pairs? -- Alex Bligh