From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 01 Dec 2010 14:24:43 +0100 (CET) Received: from h5.dl5rb.org.uk ([81.2.74.5]:60323 "EHLO h5.dl5rb.org.uk" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1492979Ab0LANYk (ORCPT ); Wed, 1 Dec 2010 14:24:40 +0100 Received: from h5.dl5rb.org.uk (localhost.localdomain [127.0.0.1]) by h5.dl5rb.org.uk (8.14.4/8.14.3) with ESMTP id oB1DOciE002341; Wed, 1 Dec 2010 13:24:38 GMT Received: (from ralf@localhost) by h5.dl5rb.org.uk (8.14.4/8.14.4/Submit) id oB1DObIB002339; Wed, 1 Dec 2010 13:24:37 GMT Date: Wed, 1 Dec 2010 13:24:37 +0000 From: Ralf Baechle To: naveen yadav Cc: kernelnewbies@nl.linux.org, linux-arm-kernel@lists.arm.linux.org.uk, linux-mips@linux-mips.org Subject: Re: Change of Default kernel page size i.e 4KB Message-ID: <20101201132437.GA32555@linux-mips.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 28580 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Wed, Dec 01, 2010 at 01:50:13PM +0530, naveen yadav wrote: > Cc: kernelnewbies@nl.linux.org, > linux-arm-kernel-request@lists.arm.linux.org.uk, ^^^^^^^^ WTF? > linux-mips@linux-mips.org > I have few drivers and very big application running on ARM and MIPS target. > I want to check the performance by changing the page size ie. > > 8K, 16K, 32K etc. > > Is it possile, If yes then what all care i need to take . For MIPS: Rebuild kernel with support for the new kernel size. Few MIPS cores. Note that the `oddŽ page sizes, that those that aren't a power of 4 are only supported by Cavium while all MIPS III and newer processors support even `evenŽ sizes 4KB, 16KB and 64KB. Aside of rebuilding the kernel you also need a suitable userland; older versions of binutils will produce binaries that only run for 4kB page sizes. For ARM the page size is fixed at 4kB which will simplify your benchmarking efforts ;) Performance gains very much depends on the workload but in general larger sizes are beneficial except maybe for systems with very little memory. Ralf From mboxrd@z Thu Jan 1 00:00:00 1970 From: ralf@linux-mips.org (Ralf Baechle) Date: Wed, 1 Dec 2010 13:24:37 +0000 Subject: Change of Default kernel page size i.e 4KB In-Reply-To: References: Message-ID: <20101201132437.GA32555@linux-mips.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Dec 01, 2010 at 01:50:13PM +0530, naveen yadav wrote: > Cc: kernelnewbies at nl.linux.org, > linux-arm-kernel-request at lists.arm.linux.org.uk, ^^^^^^^^ WTF? > linux-mips at linux-mips.org > I have few drivers and very big application running on ARM and MIPS target. > I want to check the performance by changing the page size ie. > > 8K, 16K, 32K etc. > > Is it possile, If yes then what all care i need to take . For MIPS: Rebuild kernel with support for the new kernel size. Few MIPS cores. Note that the `odd? page sizes, that those that aren't a power of 4 are only supported by Cavium while all MIPS III and newer processors support even `even? sizes 4KB, 16KB and 64KB. Aside of rebuilding the kernel you also need a suitable userland; older versions of binutils will produce binaries that only run for 4kB page sizes. For ARM the page size is fixed at 4kB which will simplify your benchmarking efforts ;) Performance gains very much depends on the workload but in general larger sizes are beneficial except maybe for systems with very little memory. Ralf