From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1OTHNq-0005Oo-MK for mharc-grub-devel@gnu.org; Mon, 28 Jun 2010 12:40:34 -0400 Received: from [140.186.70.92] (port=41834 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OTHNn-0005NQ-Aq for grub-devel@gnu.org; Mon, 28 Jun 2010 12:40:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OTHNl-00058i-EQ for grub-devel@gnu.org; Mon, 28 Jun 2010 12:40:31 -0400 Received: from gateway09.websitewelcome.com ([67.18.103.4]:34591) by eggs.gnu.org with smtp (Exim 4.69) (envelope-from ) id 1OTHNl-00058H-1D for grub-devel@gnu.org; Mon, 28 Jun 2010 12:40:29 -0400 Received: (qmail 21878 invoked from network); 28 Jun 2010 16:46:36 -0000 Received: from gator297.hostgator.com (74.53.228.114) by gateway09.websitewelcome.com with SMTP; 28 Jun 2010 16:46:36 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=gibibit.com; h=Received:Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding; b=YcV9XftT/rS0YSOV1YJE1zIbSzPi9Mpndj14YwjYWkiJXrj1ZLnaaTd97V757g1mcjmsxRCunfQX8YHVnAM5G6Tn5uNhFSzA840zx3ieinfdmgNtLr9hhkKZZ/Y7eXA2; Received: from spk.venturedesignservices.com ([65.61.115.34]:38028 helo=svelte) by gator297.hostgator.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.69) (envelope-from ) id 1OTHNb-0000ai-TW; Mon, 28 Jun 2010 11:40:20 -0500 Date: Mon, 28 Jun 2010 09:40:21 -0700 From: Colin D Bennett To: The development of GNU GRUB Message-ID: <20100628094021.77b3667f@svelte> In-Reply-To: <20100625085834.GM21862@riva.ucam.org> References: <20100625085834.GM21862@riva.ucam.org> X-Mailer: Claws Mail 3.7.4 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator297.hostgator.com X-AntiAbuse: Original Domain - gnu.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - gibibit.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) Cc: cjwatson@ubuntu.com Subject: Re: [RFC] Hacky MTRR support X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Jun 2010 16:40:32 -0000 On Fri, 25 Jun 2010 09:58:34 +0100 Colin Watson wrote: > I recently posted ("Subject: [PATCH] Optimise memset on i386" - > sorry, I don't seem to have a route to lists.gnu.org at the moment so > I can't post an archive link) about optimising GRUB's video > initialisation, and hinted that it might be possible to do better by > implementing MTRRs as well in order to allow the system to combine > writes to video memory rather than taking a cache stall for every > single write. I can report that, at least on the hardware I was > using, it does make a significant difference: filling the screen with > solid colour now takes 10 milliseconds rather than 160! This ended > up shaving about a second off the boot time of the project I'm > working on. In addition to the improved startup speed, I see the potential for a huge increase in graphical menu responsiveness if caching is enabled. Would framebuffer draw and image blitting performance be improved by using write-combining with MTRRs? Regards, Colin