From owner-freebsd-alpha Tue Sep 1 09:32:57 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA06404 for freebsd-alpha-outgoing; Tue, 1 Sep 1998 09:32:57 -0700 (PDT) (envelope-from owner-freebsd-alpha@FreeBSD.ORG) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA06393 for ; Tue, 1 Sep 1998 09:32:51 -0700 (PDT) (envelope-from gallatin@duke.cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.8.5/8.8.5) with ESMTP id MAA13371; Tue, 1 Sep 1998 12:31:49 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.8.8/8.8.8) id MAA22540; Tue, 1 Sep 1998 12:31:49 -0400 (EDT) (envelope-from gallatin) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Tue, 1 Sep 1998 12:31:48 -0400 (EDT) To: mjacob@feral.com Cc: freebsd-alpha@FreeBSD.ORG Subject: Re: Alpha Install - oops! In-Reply-To: References: <13804.2770.473870.7600@grasshopper.cs.duke.edu> X-Mailer: VM 6.43 under 20.4 "Emerald" XEmacs Lucid Message-ID: <13804.8316.576176.582569@grasshopper.cs.duke.edu> Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Matthew Jacob writes: > > > I'd watch this for crossing page boundaries on reads if you're using any > S/G map stuff. In fact, I'd have an extra mapping at the end of > the S/G list that just remaps the first page so that any prefetch > on a read won't get a fault but will just pick up known good data. Gee, I'd hope a GL would be smart enough not to prefectch past the end of a S/G segment; I do know that the page-boundry DMA restriction is gone on GL's. However, I use the direct-map segment in my Myrinet drivers (on DU & on *BSD), so I can't verify that it doesn't happen. Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message