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