From owner-freebsd-arch@FreeBSD.ORG Fri Jun 15 07:41:37 2007 Return-Path: X-Original-To: freebsd-arch@freebsd.org Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 5356E16A469 for ; Fri, 15 Jun 2007 07:41:37 +0000 (UTC) (envelope-from ivo.vachkov@gmail.com) Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.233]) by mx1.freebsd.org (Postfix) with ESMTP id F283813C465 for ; Fri, 15 Jun 2007 07:41:31 +0000 (UTC) (envelope-from ivo.vachkov@gmail.com) Received: by wx-out-0506.google.com with SMTP id h28so695504wxd for ; Fri, 15 Jun 2007 00:41:31 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=enMM8ypIyEwlblfjXcON+DP112MqUzU1v+MLeGUWwQrbRJEBCZID9YuasCd4A03NMZe4TEahXDeVaBKJzxMr9hxZs+0w0HPFUEDmhCqVfRll4LTouINxdpAT9A/Of04QFmAa1y1LtK9RC+Tt5Voyq87UI7KWFGxw2zf2KUUIamw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=l9gbsb4x9hUYcJUhF5Mw9AFnebbZzzU2RkNqLcNHgofcKpGIdKkF5+BTzTwqFmL2En6mVfktg6wBrniXi/wPkaTmk3DDIN4lf4uvbXkfCaUI7GbXGPBjjnWZPl4hInPilYGuDU0ZqNj5s81CaFFRqP5N/LILNb50pNuNsiYesRk= Received: by 10.90.105.19 with SMTP id d19mr2283540agc.1181891613032; Fri, 15 Jun 2007 00:13:33 -0700 (PDT) Received: by 10.90.119.18 with HTTP; Fri, 15 Jun 2007 00:13:32 -0700 (PDT) Message-ID: Date: Fri, 15 Jun 2007 10:13:32 +0300 From: "Ivo Vachkov" To: "cadastrosonline cadastrosonline" In-Reply-To: <497837.24344.qm@web57302.mail.re1.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <497837.24344.qm@web57302.mail.re1.yahoo.com> Cc: fbsd arch Subject: Re: VM X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jun 2007 07:41:37 -0000 On 6/14/07, cadastrosonline cadastrosonline wrote: > "FreeBSD's memory allocation code implements page coloring optimizations,= which means > that the memory allocation code will attempt to locate free pages that ar= e contiguous > from the point of view of the cache. For example, if page 16 of physical = memory is > assigned to page 0 of a process's virtual memory and the cache can hold 4= pages, the page > coloring code will not assign page 20 of physical memory to page 1 of a p= rocess's virtual > memory." > > From fbsd books, I don't understand why it links page 16 of physical memo= ry to page 0 then talks about page 20 of physcal memory to page 1, ok it wi= ll say it will sign to page 21 because of the page coloring, but thats not = what i didnt get. > > If the cache holds 4 pages, why wouldn't the physical page 20 sign to pag= e 4 or 8 instead? Why 1? lol :> i see its signing the VM as 0,1,2,3,4 and t= he physical as 4,8,16,20...could anyone explain that? > > I think, if virtual memory page 0 maps on physical memory page 16, then virtual memory page 1 would map to physical memory page 17 and that's the main idea. Instead, if you map vm page 1 to phys page 20 this will require cache invalidation on access. > > > _________________________________________________________________________= ___________ > Novo Yahoo! Cad=EA? - Experimente uma nova busca. > http://yahoo.com.br/oqueeuganhocomisso > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" > --=20 "UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity." Dennis Ritchie