From owner-freebsd-hackers@FreeBSD.ORG Sat Nov 12 07:45:27 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 482E816A41F for ; Sat, 12 Nov 2005 07:45:27 +0000 (GMT) (envelope-from pyunyh@gmail.com) Received: from zproxy.gmail.com (zproxy.gmail.com [64.233.162.202]) by mx1.FreeBSD.org (Postfix) with ESMTP id BFD7943D45 for ; Sat, 12 Nov 2005 07:45:26 +0000 (GMT) (envelope-from pyunyh@gmail.com) Received: by zproxy.gmail.com with SMTP id 9so342069nzo for ; Fri, 11 Nov 2005 23:45:26 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:cc:subject:message-id:reply-to:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=HWixwWw1tWm9/zt/GmX6Al0WTFtLkYP4Y1Uy7iGEgsDxXzo7r/p47MrO1izhLliMeXk9KQ63QuXjEd4NO5uPdhhgv6wXcFE+CaR9TSGWyqdtmIkzjaRkOYwU6v618J9bMROBKPLEJFXIV5VxW/PexbGWU/LwMLgSZf/pH5lATF4= Received: by 10.36.247.78 with SMTP id u78mr2055938nzh; Fri, 11 Nov 2005 23:45:26 -0800 (PST) Received: from michelle.rndsoft.co.kr ( [211.32.202.217]) by mx.gmail.com with ESMTP id 39sm290485nzk.2005.11.11.23.45.22; Fri, 11 Nov 2005 23:45:26 -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 jAC7iKKC019415 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 12 Nov 2005 16:44:20 +0900 (KST) (envelope-from yongari@gmail.com) Received: (from yongari@localhost) by michelle.rndsoft.co.kr (8.13.1/8.13.1/Submit) id jAC7iIKn019414; Sat, 12 Nov 2005 16:44:18 +0900 (KST) (envelope-from yongari@gmail.com) Date: Sat, 12 Nov 2005 16:44:18 +0900 From: Pyun YongHyeon To: Peter Jeremy Message-ID: <20051112074418.GE18405@rndsoft.co.kr> References: <20051112071815.GD18405@rndsoft.co.kr> <20051112073711.GE39882@cirb503493.alcatel.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051112073711.GE39882@cirb503493.alcatel.com.au> User-Agent: Mutt/1.4.2.1i Cc: freebsd-hackers@freebsd.org Subject: Re: 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 07:45:27 -0000 On Sat, Nov 12, 2005 at 06:37:11PM +1100, Peter Jeremy wrote: > On Sat, 2005-Nov-12 16:18:15 +0900, Pyun YongHyeon wrote: > >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. > > 36b is one track. My suspicion is that the system isn't fast enough > to read sequential blocks, one at a time, so you're forced to wait > a complete revolution (plus a bit) for each block you read. > Yes, it could be. But I think the machine is fast enough to read sequential blocks. Part of dmesg shows: CPU: Intel Pentium III (800.03-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x686 Stepping = 6 Features=0x387fbff real memory = 402587648 (383 MB) avail memory = 384385024 (366 MB) FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 And I think I got much better result on slow i386 machines except this one. -- Regards, Pyun YongHyeon