From owner-freebsd-current Thu Mar 5 09:18:04 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA12001 for freebsd-current-outgoing; Thu, 5 Mar 1998 09:18:04 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from ns2.cetlink.net (root@ns2.cetlink.net [209.54.54.20]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA11980 for ; Thu, 5 Mar 1998 09:17:59 -0800 (PST) (envelope-from jak@cetlink.net) Received: from exit1.i485.net (i485-gw.cetlink.net [209.198.15.1]) by ns2.cetlink.net (8.8.5/8.8.5) with SMTP id MAA04577; Thu, 5 Mar 1998 12:17:53 -0500 (EST) From: jak@cetlink.net (John Kelly) To: John Saunders Cc: freebsd-current@FreeBSD.ORG Subject: Re: silo overflows (Was Re: 3.0-RELEASE?) Date: Thu, 05 Mar 1998 17:19:50 GMT Message-ID: <34ffdd5f.17323509@mail.cetlink.net> References: <34FE191D.1D676AC3@scitec.com.au> In-Reply-To: <34FE191D.1D676AC3@scitec.com.au> X-Mailer: Forte Agent 1.01/16.397 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by hub.freebsd.org id JAA11994 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 05 Mar 1998 14:16:45 +1100, John Saunders wrote: >If you use an IDE disk then 10 to 1 that's the problem. Particularly >if the IDE driver is doing multi-sector transfers. Interrupts must be >disabled during IDE PIO transfers (or you can risk data corruption) >and the time taken to transfer, say 16 sectors, is significant. When Sorry, but this is a myth perpetuated by some Linux users. FreeBSD does not have this problem with IDE disks. I have put Linux and FreeBSD side by side and tested this. Linux fails the test, while FreeBSD never misses a serial byte, even under heavy loading of the disk. The problem is related to the 650 UART support in sio.c. The 550 support works fine. >The solution is to use either a SCSI disk system, or support >busmastering IDE. The real problem is the crazy IRQ priorities of >the PC architeture. Nope, not a problem at all for FreeBSD. The IDE flaw is a Linux problem. -- Browser war over, Mozilla now free. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message