From owner-freebsd-questions Tue Feb 5 7:18:44 2002 Delivered-To: freebsd-questions@freebsd.org Received: from aramis.rutgers.edu (aramis.rutgers.edu [128.6.4.2]) by hub.freebsd.org (Postfix) with ESMTP id 63E0E37B428 for ; Tue, 5 Feb 2002 07:18:40 -0800 (PST) Received: from cs.rutgers.edu (sirtaki.rutgers.edu [128.6.171.146]) by aramis.rutgers.edu (8.8.8/8.8.8) with ESMTP id KAA21375 for ; Tue, 5 Feb 2002 10:18:39 -0500 (EST) Message-ID: <3C5FF7A5.7000805@cs.rutgers.edu> Date: Tue, 05 Feb 2002 10:17:57 -0500 From: Aniruddha Bohra User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.4) Gecko/20011128 Netscape6/6.2.1 X-Accept-Language: en-us MIME-Version: 1.0 To: freebsd-questions@freebsd.org Subject: Does this affect FreeBSD? Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hi Came across this while trying to find why my computer spontaneously reboots. Apparently there is some bug/feature in the AMD Athlon chip which interacts with the graphics card to cause the reboot. Does this affect the FreeBSD systems as well? http://www.theregister.co.uk/content/3/23749.html ---Article Snip Daniel concludes that neither side is guilty; that it isn't an AMD bug, more a feature; but he also recommends that kernel hackers find a new problem to this particular situation. It appears that the GART (Graphics Address Remapping Table) which feeds the AGP card with system memory isn't cache coherent. Although both Linux (and apparently Windows 2000) expect it to be. The GART lays out memory for the AGP card in a contiguous block, but the real memory that's being addressed. of course, lies all over the place - having been paged out in 4k blocks from main system memory. Intel added 4MB pages, and the temporary workaround for both Linux and Windows 2000 is to disable the 4MB page option. AMD concludes:- "Our conclusion is that the operating system is creating coherency problems within the system by creating cacheable translation to AGP GART-mapped physical memory... When the cache-line eviction occurs the stale data written to physical memory has fatal side effects." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message