From owner-freebsd-arch@FreeBSD.ORG Wed Mar 5 23:43:10 2014 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A1B79F57 for ; Wed, 5 Mar 2014 23:43:10 +0000 (UTC) Received: from mail-qg0-x22d.google.com (mail-qg0-x22d.google.com [IPv6:2607:f8b0:400d:c04::22d]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 5D11CE32 for ; Wed, 5 Mar 2014 23:43:10 +0000 (UTC) Received: by mail-qg0-f45.google.com with SMTP id j5so4961000qga.4 for ; Wed, 05 Mar 2014 15:43:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=jPUy+xS9wlTnZdxvCFGYxLmLLjJm16E8eviO96aKpXI=; b=TJakij1b0P9IlaCWhGpvEUG9TgOCf7YtPIUJuYpC0JDxr9iXXBdVDVeqUKDJEfAtlE nMQudAGo/UZHYAGsPgXhZnohZ6jH/AExnCp1DsNVl8rILWhVnivMNu8VMCZDcmwCvDPw r7s5PEC9qWbMQisQnfNHU16pRB13nLI7QjznQupEqWAlV6Hb91+JGQ8CRu7A+w3ethbj xTK94y54/Rp9WPAo+tbgwKPOziuddKyXCFENiVGmITtJu56ON/DlcBaVjSClfBTCQz/E 57kdxHs2K9cVrt2YKIi2qOTh+3p1p2C9bo6b3L2p6Bx5CmCr79buSeBFcg+M3hCbZ1Yr u0Bw== MIME-Version: 1.0 X-Received: by 10.140.81.244 with SMTP id f107mr5550714qgd.104.1394062989537; Wed, 05 Mar 2014 15:43:09 -0800 (PST) Sender: chmeeedalf@gmail.com Received: by 10.140.28.131 with HTTP; Wed, 5 Mar 2014 15:43:09 -0800 (PST) In-Reply-To: <20140306013120.H1530@besplex.bde.org> References: <42130.1393829535@critter.freebsd.dk> <5314B2A2.3060100@pix.net> <60475.1393876211@critter.freebsd.dk> <20140304071445.Y3158@besplex.bde.org> <20140305230458.L1053@besplex.bde.org> <20140306013120.H1530@besplex.bde.org> Date: Wed, 5 Mar 2014 15:43:09 -0800 X-Google-Sender-Auth: lpBGcF5KnyVo22Dmn5BoDDDvb8M Message-ID: Subject: Re: newcons fb driver From: Justin Hibbits To: Bruce Evans Content-Type: text/plain; charset=UTF-8 Cc: Poul-Henning Kamp , freebsd-arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Mar 2014 23:43:10 -0000 On Wed, Mar 5, 2014 at 7:02 AM, Bruce Evans wrote: > On Thu, 6 Mar 2014, Bruce Evans wrote: > >> On Tue, 4 Mar 2014, Justin Hibbits wrote: >>> >>> Without some kind of optimization, newcons on powerpc is unacceptably >>> slow. >> >> >> How slow is that exactly? If the frame buffer speed is 50MB/S, then >> 16x8 characters with 256 colors can be written at 390K/S. This is >> acceptable. If the frame buffer is much slower than that, then it is >> too slow, at least without hardware scrolling. > > > I forgot to mention that u$ doesn't solve this problem in WinXP. The > speed is not too bad in normal mode (only about 30 times slower than > syscons - the scrolling speed is 30000 lines/second instead of 1000000). > But in safe mode, a simple graphics driver is used and it is horribly > slow. Safe mode with command prompt gives an MSDOS prompt in a > maximized terminal window, so the problem is very noticeable (the > scrolling speed is 4 lines per second = 12 seconds per screenful). > Apparently normal mode uses acceleration to be not very slow, but safe > mode is too simple to do that. The FreeBSD console driver needs to > be even simpler so that it works as a low level console. > > Bruce The ofwfb syscons driver is much faster than newcons, so a frame buffer can be made relatively fast (within reason). It's newcons that's slow, and my assumption currently is the byte-oriented writes instead of word size. - Justin