Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 26 Feb 2003 16:06:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 26 Feb 2003 16:06:06 -0500 Received: from franka.aracnet.com ([216.99.193.44]:51591 "EHLO franka.aracnet.com") by vger.kernel.org with ESMTP id ; Wed, 26 Feb 2003 16:06:05 -0500 Date: Wed, 26 Feb 2003 13:16:15 -0800 From: "Martin J. Bligh" To: Andi Kleen cc: lse-tech@projects.sourceforge.net, akpm@digeo.com, linux-kernel@vger.kernel.org Subject: Re: [Lse-tech] [PATCH] New dcache / inode hash tuning patch Message-ID: <6000000.1046294173@[10.10.2.4]> In-Reply-To: <20030226183304.GA30836@wotan.suse.de> References: <20030226164904.GA21342@wotan.suse.de> <15730000.1046283789@[10.10.2.4]> <20030226183304.GA30836@wotan.suse.de> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1498 Lines: 34 >> It actually seems a fraction slower (see systimes for Kernbench-16, >> for instance). > > Can you play a bit with the hash table sizes? Perhaps double the > dcache hash and half the inode hash ? I quadrupled the dcache hash size ... helped a bit. Is still a little slower, which I don't understand ... your plan should make it go faster, AFAICS. Those off-node accesses to ZONE_NORMAL are really expensive for me. Kernbench-2: (make -j N vmlinux, where N = 2 x num_cpus) Elapsed User System CPU 2.5.62-mjb3 44.24 558.12 94.17 1473.83 2.5.62-mjb3-andi 44.28 557.90 95.79 1475.67 2.5.62-mjb3-andi-4x 44.20 557.96 94.77 1475.83 Kernbench-16: (make -j N vmlinux, where N = 16 x num_cpus) Elapsed User System CPU 2.5.62-mjb3 45.19 560.95 114.77 1495.00 2.5.62-mjb3-andi 45.39 561.29 117.73 1495.67 2.5.62-mjb3-andi-4x 45.34 560.54 116.85 1493.50 > I suspect it really just needs a better hash function. I'll cook > something up based on FNV hash. Sounds good ;-) M. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/