From owner-freebsd-current@FreeBSD.ORG Mon Oct 25 18:18:29 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B1B8516A4CE; Mon, 25 Oct 2004 18:18:29 +0000 (GMT) Received: from mail.dt.e-technik.uni-dortmund.de (mail.dt.e-technik.Uni-Dortmund.DE [129.217.163.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3F61043D1D; Mon, 25 Oct 2004 18:18:29 +0000 (GMT) (envelope-from ma@dt.e-technik.uni-dortmund.de) Received: from localhost (localhost [127.0.0.1])7E91C456C9; Mon, 25 Oct 2004 20:18:28 +0200 (CEST) Received: from mail.dt.e-technik.uni-dortmund.de ([127.0.0.1]) by localhost (krusty [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 27505-01-2; Mon, 25 Oct 2004 20:18:28 +0200 (CEST) Received: from m2a2.dyndns.org (p548545DD.dip.t-dialin.net [84.133.69.221]) 33C9C456BD; Mon, 25 Oct 2004 20:18:28 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by merlin.emma.line.org (Postfix) with ESMTP id 278A2DA766; Mon, 25 Oct 2004 20:18:27 +0200 (CEST) Received: from merlin.emma.line.org ([127.0.0.1]) by localhost (m2a2.dyndns.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 31014-02; Mon, 25 Oct 2004 20:18:26 +0200 (CEST) Received: by merlin.emma.line.org (Postfix, from userid 500) id C4C0DDA765; Mon, 25 Oct 2004 20:18:26 +0200 (CEST) To: Scott Long In-Reply-To: <41796D6D.7000108@freebsd.org> (Scott Long's message of "Fri, 22 Oct 2004 14:28:29 -0600") References: <417960C2.8040007@freebsd.org> <20041022194008.GA23778@odin.ac.hmc.edu> <41796396.5070804@freebsd.org> <41796D6D.7000108@freebsd.org> From: Matthias Andree Date: Mon, 25 Oct 2004 20:18:26 +0200 Message-ID: User-Agent: Gnus/5.110003 (No Gnus v0.3) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: by amavisd-new at dt.e-technik.uni-dortmund.de cc: freebsd-current@freebsd.org cc: Garance A Drosihn Subject: Re: Annoying SCSI waiting... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Oct 2004 18:18:29 -0000 Scott Long writes: > For just about everyone, a value of 2 seconds or less is just fine. > For those with tape drives, changers, and (less likely) cdroms, a > long delay after reset is still quite necessary. There are two knobs > to adjust this, and I'd like GENERIC to remain compatible. It's 15 > seconds, not 2 minutes. You get a longer delay that that just trying > to set up the inital page tables on a large memory machine! One thing that was suggested for Linux but rejected for 2.6 is probing hardware in parallel. I wonder if a threaded boot-up could be made (not for 5.X though) that lets the kernel proceed with other initialization while the scsi driver waits for the devices to settle. Some scheme for stable device enumeration may then be needed to avoid inconsistencies with cold start vs. fastreboot. One should think when the driver has claimed all the I/O ranges and IRQs and DMA channels it needs, it would be safe to background itself and report back later, at the latest just before launching /etc/rc or /sbin/init or whatever. -- Matthias Andree