From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 21 Jul 2006 12:15:43 +0100 (BST) Received: from bender.bawue.de ([193.7.176.20]:35542 "EHLO bender.bawue.de") by ftp.linux-mips.org with ESMTP id S8133492AbWGULPe (ORCPT ); Fri, 21 Jul 2006 12:15:34 +0100 Received: from lagash (mipsfw.mips-uk.com [194.74.144.146]) (using TLSv1 with cipher DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by bender.bawue.de (Postfix) with ESMTP id A0C1E46034; Fri, 21 Jul 2006 13:15:33 +0200 (MEST) Received: from ths by lagash with local (Exim 4.62) (envelope-from ) id 1G3sEi-0003Lb-E9; Fri, 21 Jul 2006 11:28:00 +0100 Date: Fri, 21 Jul 2006 11:28:00 +0100 To: pulsar@kpsws.com Cc: linux-mips@linux-mips.org Subject: Re: reserved pages and zero pages question Message-ID: <20060721102800.GA4456@networkno.de> References: <1153414322.20352.268.camel@sakura.staff.proxad.net> <20060720191836.GA22361@linux-mips.org> <15360.194.171.252.100.1153474088.squirrel@mail.kpsws.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15360.194.171.252.100.1153474088.squirrel@mail.kpsws.com> User-Agent: Mutt/1.5.12-2006-07-14 From: Thiemo Seufer 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: 12051 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: ths@networkno.de Precedence: bulk X-list: linux-mips pulsar@kpsws.com wrote: > Hi, > > In my kernel startup I see the memory usage printed as: > > Memory: 125312k/131072k available (1977k kernel code, 5648k reserved, 287k > data, 1664k init, 0k highmem) > > I wonder where the reserved pages are used for and how we can minimize it > for small memory systems. Most of that is the ramdisk you included. :-) It normally given back once the ramdisk is decompressed. > In my search I see that in arcm/mips/mm/init.c there are zero-pages > allocated and put to reserved. > > Where are the zero pages used for and can we do without ? They provide a clean zeroed page which gets mapped read-only (probably for copy-on-write). You can't do without. Thiemo