From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263713AbUEGUCu (ORCPT ); Fri, 7 May 2004 16:02:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263167AbUEGUC3 (ORCPT ); Fri, 7 May 2004 16:02:29 -0400 Received: from over.ny.us.ibm.com ([32.97.182.111]:38857 "EHLO over.ny.us.ibm.com") by vger.kernel.org with ESMTP id S263713AbUEGUAo (ORCPT ); Fri, 7 May 2004 16:00:44 -0400 Date: Fri, 7 May 2004 08:04:15 -0500 From: "Jose R. Santos" To: Andrew Morton Cc: "Jose R. Santos" , linux-kernel@vger.kernel.org, anton@samba.org, dheger@us.ibm.com, slpratt@us.ibm.com Subject: Re: [PATCH] dentry and inode cache hash algorithm performance changes. Message-ID: <20040507130415.GA1537@rx8.ibm.com> References: <20040430191539.GC14271@rx8.ibm.com> <20040430131832.45be6956.akpm@osdl.org> <20040430205701.GG14271@rx8.ibm.com> <20040430213324.GK14271@rx8.ibm.com> <20040430150256.25735762.akpm@osdl.org> <20040504131223.GA28009@austin.ibm.com> <20040504115510.696184dc.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: 7BIT In-Reply-To: <20040504115510.696184dc.akpm@osdl.org> (from akpm@osdl.org on Tue, May 04, 2004 at 13:55:10 -0500) X-Mailer: Balsa 2.0.17 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 05/04/04 13:55:10, Andrew Morton wrote: > > Andrew - Is there any workload you want me to run to show that this hash > > function is going to be equal or better that the one already provided > > in Linux? > > Not really - it sounds like you've covered it pretty well. Did you try SDET? > > It could be that reducing the hash table size will turn pretty much any > workload into a test of the hash quality. Sorry for the late reply... Steve Pratt seem to have a SDET setup already and he did me the favor of running SDET with a reduce dentry entry hash table size. I belive that his table suggest that less than 3% change is acceptable variability, but overall he got a 5% better number using the new hash algorith. -JRS ========================================================================= A) x4408way1.sdet.2.6.5100000-8p.04-05-05_12.08.44 vs B) x4408way1.sdet.2.6.5+hash-100000-8p.04-05-05_11.48.02 <6>Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) <4>Inode-cache hash table entries: 1048576 (order: 10, 4194304 bytes) Results:Throughput tolerance = 0.00 + 3.00% of A A B Threads Ops/sec Ops/sec %diff diff tolerance ---------- ------------ ------------ -------- ------------ ------------ 1 4341.9300 4401.9500 1.38 60.02 130.26 2 8242.2000 8165.1200 -0.94 -77.08 247.27 4 15274.4900 15257.1000 -0.11 -17.39 458.23 8 21326.9200 21320.7000 -0.03 -6.22 639.81 16 23056.2100 24282.8000 5.32 1226.59 691.69 * 32 23397.2500 24684.6100 5.50 1287.36 701.92 * 64 23372.7600 23632.6500 1.11 259.89 701.18 128 17009.3900 16651.9600 -2.10 -357.43 510.28 =========================================================================