From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964956AbWD0GTD (ORCPT ); Thu, 27 Apr 2006 02:19:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964957AbWD0GTD (ORCPT ); Thu, 27 Apr 2006 02:19:03 -0400 Received: from smtp101.mail.mud.yahoo.com ([209.191.85.211]:41147 "HELO smtp101.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S964956AbWD0GTC (ORCPT ); Thu, 27 Apr 2006 02:19:02 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=E7wiZCkV3mlurjVCE3aZUkcjB1Ee8+5ptWfFEweLztObHpq9mWab6aseAc+iTjtewAzvTe2/4io+iXt+cObH+Pguxayq7hcJbPdhddX8d/HbmLgw9CpDasdDDgWmCZPzJn15aBsYotJCQ5DsowfWjAuoAYD632+9uwK4I7CEq28= ; Message-ID: <44505FA6.70508@yahoo.com.au> Date: Thu, 27 Apr 2006 16:07:34 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: "Chen, Kenneth W" CC: "'Jens Axboe'" , linux-kernel@vger.kernel.org, "'Nick Piggin'" , "'Andrew Morton'" , linux-mm@kvack.org Subject: Re: Lockless page cache test results References: <4t153d$r2dpi@azsmga001.ch.intel.com> In-Reply-To: <4t153d$r2dpi@azsmga001.ch.intel.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Chen, Kenneth W wrote: > Jens Axboe wrote on Wednesday, April 26, 2006 12:46 PM > >>>It's interesting, single threaded performance is down a little. Is >>>this significant? In some other results you showed me with 3 splices >>>each running on their own file (ie. no tree_lock contention), lockless >>>looked slightly faster on the same machine. >> >>I can do the same numbers on a 2-way em64t for comparison, that should >>get us a little better coverage. > > > > I throw the lockless patch and Jens splice-bench into our benchmark harness, > here are the numbers I collected, on the following hardware: > > (1) 2P Intel Xeon, 3.4 GHz/HT, 2M L2 > (2) 4P Intel Xeon, 3.0 GHz/HT, 8M L3 > (3) 4P Intel Xeon, 3.0 GHz/DC/HT, 2M L2 (per core) > > Here are the graph: Thanks a lot Ken. So pagecache lookup performance goes up about 15-25% in single threaded tests on your P4s. Phew, I wasn't dreaming it. It is a pity that ipf hasn't improved similarly (and even slowed down a bit, if Jens' numbers are significant to that range). Next time I spend some cycles on lockless pagecache, I'll try to scrounge an ipf and see if I can't improve it (I don't expect miracles). Thanks, Nick -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com