From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ocean.emcraft.com (ocean.emcraft.com [213.221.7.182]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id B557DDDEE0 for ; Sat, 20 Oct 2007 01:39:57 +1000 (EST) From: Yuri Tikhonov To: Paul Mackerras Subject: Re: [PATCH] ppc44x: support for 256K PAGE_SIZE Date: Fri, 19 Oct 2007 19:37:23 +0400 References: <200710181108.19413.yur@emcraft.com> <18199.60025.563689.10810@cargo.ozlabs.ibm.com> In-Reply-To: <18199.60025.563689.10810@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200710191937.23638.yur@emcraft.com> Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Friday 19 October 2007 03:21, Paul Mackerras wrote: > Have you measured the performance using a 64kB page size? If so, how > does it compare with the 256kB page size? I measured the performance of the sequential full-stripe write operations to a RAID-5 array (P values below are in MB per second) using the h/w accelerated RAID-5 driver. Here are the comparative results for the different PAGE_SIZE values: PAGE_SIZE = 4K: P = 66 MBps; PAGE_SIZE = 16K: P = 145 MBps; PAGE_SIZE = 64K: P = 196 MBps; PAGE_SIZE = 256K: P = 217 MBps. > The 64kB page size has the attraction that no binutils changes are > required. That's true, but the additional performance is an attractive thing too. > > Paul. > -- Yuri Tikhonov, Senior Software Engineer Emcraft Systems, www.emcraft.com