From owner-freebsd-current Thu Jan 31 18:21:22 2002 Delivered-To: freebsd-current@freebsd.org Received: from rwcrmhc51.attbi.com (rwcrmhc51.attbi.com [204.127.198.38]) by hub.freebsd.org (Postfix) with ESMTP id 309B637B405; Thu, 31 Jan 2002 18:21:13 -0800 (PST) Received: from peter3.wemm.org ([12.232.27.13]) by rwcrmhc51.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020201022112.QWFR26243.rwcrmhc51.attbi.com@peter3.wemm.org>; Fri, 1 Feb 2002 02:21:12 +0000 Received: from overcee.wemm.org (overcee.wemm.org [10.0.0.3]) by peter3.wemm.org (8.11.0/8.11.0) with ESMTP id g112LCs57915; Thu, 31 Jan 2002 18:21:12 -0800 (PST) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by overcee.wemm.org (Postfix) with ESMTP id 227833809; Thu, 31 Jan 2002 18:21:12 -0800 (PST) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Kenneth Culver Cc: "Cameron, Frank" , Terry Lambert , David Malone , "'freebsd-bugs@freebsd.org'" , "'freebsd-current@freebsd.org'" Subject: Re: AMD AGP Bug In-Reply-To: <20020131135127.V22577-100000@alpha.yumyumyum.org> Date: Thu, 31 Jan 2002 18:21:12 -0800 From: Peter Wemm Message-Id: <20020201022112.227833809@overcee.wemm.org> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Kenneth Culver wrote: > Yeah, that's what I saw on linux-kernel... > > Ken We need to use the PAT cpu_features feature. This gives us 8 page attribute modes instead of simple no-cache / writethrough flags. We can (and must) control more carefully the speculative hardware prefetch, for example. I've been thinking about this with the pmap revamp that I'm working on. It may solve the athlon problems too. > On Thu, 31 Jan 2002, Cameron, Frank wrote: > > > From what was posted on the linux-kernel list the problem is the OS > > doing the wrong thing not the hardware. I originally asked the > > question (albeit not worded as clearly as I should have) because if > > Microsoft and Linux programmers made the same mistake, might > > FreeBSD have also. > > > > > -----Original Message----- > > > From: Kenneth Culver [mailto:culverk@yumyumyum.org] > > > Sent: Thursday, January 31, 2002 10:42 AM > > > To: Terry Lambert > > > Cc: David Malone; Cameron, Frank; 'freebsd-bugs@freebsd.org'; > > > 'freebsd-current@freebsd.org' > > > Subject: Re: AMD AGP Bug > > > > > > > > > > There's actually a seperate TLB bug, but FreeBSD doesn't > > > > trigger that one, either (Linux can tickle it, when there > > > > are certain specific circumstances met). > > > > > > > Well, I think I know what you're talking about, linux > > > allocates agpgart > > > memory without setting a "non-cacheable" bit, and then the > > > agp card writes > > > to that memory, but the cpu cached it already, which makes > > > the cache wrong > > > or something like that, and causes the crashes/hangs. I know this is a > > > greatly simplified version of the real problem, but I think this is a > > > linux bug not necesarily an amd bug. > > > > > > Ken > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-bugs" in the body of the message > Cheers, -Peter -- Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message