From owner-freebsd-hackers@FreeBSD.ORG Sat Nov 12 07:19:23 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 41F2E16A41F for ; Sat, 12 Nov 2005 07:19:23 +0000 (GMT) (envelope-from pyunyh@gmail.com) Received: from zproxy.gmail.com (zproxy.gmail.com [64.233.162.194]) by mx1.FreeBSD.org (Postfix) with ESMTP id BBE8343D45 for ; Sat, 12 Nov 2005 07:19:22 +0000 (GMT) (envelope-from pyunyh@gmail.com) Received: by zproxy.gmail.com with SMTP id 8so777091nzo for ; Fri, 11 Nov 2005 23:19:21 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:subject:message-id:reply-to:mime-version:content-type:content-disposition:user-agent; b=AHPshMDYtewECA/WLf16ckKflI7f7jZ3c55x9gwNOYtPa03SMXjAfOeZhAD+uCWuZ8byTT0kiebyaPltiiqazmDkoGA4zg4OcyKc0FYk6+nac3xH7lLrdGKc051umLsN7EkzZcVskEX004exx8s//91hRPTparsZm1jzFjDqwhM= Received: by 10.36.79.19 with SMTP id c19mr2096046nzb; Fri, 11 Nov 2005 23:19:21 -0800 (PST) Received: from michelle.rndsoft.co.kr ( [211.32.202.217]) by mx.gmail.com with ESMTP id 7sm145885nzn.2005.11.11.23.19.18; Fri, 11 Nov 2005 23:19:21 -0800 (PST) Received: from michelle.rndsoft.co.kr (localhost.rndsoft.co.kr [127.0.0.1]) by michelle.rndsoft.co.kr (8.13.1/8.13.1) with ESMTP id jAC7IF8c019314 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 12 Nov 2005 16:18:15 +0900 (KST) (envelope-from yongari@gmail.com) Received: (from yongari@localhost) by michelle.rndsoft.co.kr (8.13.1/8.13.1/Submit) id jAC7IFQd019313 for freebsd-hackers@freebsd.org; Sat, 12 Nov 2005 16:18:15 +0900 (KST) (envelope-from yongari@gmail.com) Date: Sat, 12 Nov 2005 16:18:15 +0900 From: Pyun YongHyeon To: freebsd-hackers@freebsd.org Message-ID: <20051112071815.GD18405@rndsoft.co.kr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.1i Subject: poor fdc(4) performance X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Nov 2005 07:19:23 -0000 Hi, I encountered a P3 SMP system that shows poor fdc(4) performance. But when I use larger block size, say 36b, it seems it works as expected. #dd if=boot.flp of=/dev/fd0 2880+0 records in 2880+0 records out 1474560 bytes transferred in 607.483808 secs (2427 bytes/sec) #dd if=boot.flp of=/dev/fd0 bs=36b 80+0 records in 80+0 records out 1474560 bytes transferred in 48.482513 secs (30414 bytes/sec) On other P4 machine I got: #dd if=boot.flp of=/dev/fd0 2880+0 records in 2880+0 records out 1474560 bytes transferred in 51.007538 secs (28909 bytes/sec) #dd if=boot.flp of=/dev/fd0 bs=36b 80+0 records in 80+0 records out 1474560 bytes transferred in 47.972662 secs (30738 bytes/sec) This type of poor dd performance is the same symptom I'd like to solve on sparc64. On ebus based Ultrasparcs it shows almost the same phenomenon. Since I can't see any DMA or retry errors on fdc I have no idea what caused this. In addition, it works well on sbus based ultrasparcs which don't support DMA. Any ideas? -- Regards, Pyun YongHyeon