From owner-freebsd-performance@FreeBSD.ORG Mon Aug 28 09:56:28 2006 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3B67B16A4DA; Mon, 28 Aug 2006 09:56:28 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail13.syd.optusnet.com.au (mail13.syd.optusnet.com.au [211.29.132.194]) by mx1.FreeBSD.org (Postfix) with ESMTP id 82FD443D46; Mon, 28 Aug 2006 09:56:27 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail13.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k7S9uN6E011876 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Mon, 28 Aug 2006 19:56:25 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.6/8.13.6) with ESMTP id k7S9uNYX001215; Mon, 28 Aug 2006 19:56:23 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.6/8.13.6/Submit) id k7S9uMBS001214; Mon, 28 Aug 2006 19:56:22 +1000 (EST) (envelope-from peter) Date: Mon, 28 Aug 2006 19:56:22 +1000 From: Peter Jeremy To: "Jin Guojun [VFFS]" Message-ID: <20060828095622.GC747@turion.vk2pj.dyndns.org> References: <44F22CB9.9040100@lbl.gov> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wULyF7TL5taEdwHz" Content-Disposition: inline In-Reply-To: <44F22CB9.9040100@lbl.gov> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.12-2006-07-14 X-Mailman-Approved-At: Fri, 01 Sep 2006 13:26:00 +0000 Cc: freebsd-performance@freebsd.org, hardware@freebsd.org Subject: Re: reduce interrupt rate for CD/DVD drive(r) X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Aug 2006 09:56:28 -0000 --wULyF7TL5taEdwHz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, 2006-Aug-27 16:37:29 -0700, Jin Guojun [VFFS] wrote: >I have difficulty to get CD/DVD write speed above 1.6MB/s (10x for CD,=20 >or 1.1x for DVD). >The problem seems to be the interrupt rate is high (70-80% of CPU) for=20 >CD/DVD drive(r). Your drive is probably in PIO4 mode (due to there being bugs in the UDMA implementation on many drives). Check hw.ata.atapi_dma and "atacontrol mode acd0". You may find you can change to WDMA2 mode which will significantly reduce the interrupt and CPU load. You will need to do some experimenting with your drives to see what works for you. --=20 Peter Jeremy --wULyF7TL5taEdwHz Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFE8r3G/opHv/APuIcRAhEEAJ4oSVUSRiD+7eisBUxO0No/PQlqugCgilsx 1D2NcxEEb5CM3fW6DnQ65kM= =mleA -----END PGP SIGNATURE----- --wULyF7TL5taEdwHz--