From owner-freebsd-current Fri Nov 22 15: 1:13 2002 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 C249037B401; Fri, 22 Nov 2002 15:01:10 -0800 (PST) Received: from grebe.mail.pas.earthlink.net (grebe.mail.pas.earthlink.net [207.217.120.46]) by mx1.FreeBSD.org (Postfix) with ESMTP id 39C3643E9C; Fri, 22 Nov 2002 15:01:10 -0800 (PST) (envelope-from tlambert2@mindspring.com) Received: from pool0236.cvx40-bradley.dialup.earthlink.net ([216.244.42.236] helo=mindspring.com) by grebe.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 18FMnM-0004kO-00; Fri, 22 Nov 2002 15:01:09 -0800 Message-ID: <3DDEB6E6.7E61E241@mindspring.com> Date: Fri, 22 Nov 2002 14:59:50 -0800 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: John Baldwin Cc: current@FreeBSD.org, Scott Sipe , Vallo Kallaste Subject: Re: DP2 Fatal Trap References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 John Baldwin wrote: > >> > Is it any help to know that my problems on P4 stopped after enabling > >> > DISABLE_PSE? Initially I had both of these enabled, but seems that > >> > one is enough. Just FYI. > >> > >> If we can verify that DISABLE_PG_G has no effect then that would be > >> nice. > > > > It has an effect: writing CR3 or a TSS resulting in a changed CR3 > > will not invalidate TLB entries with the G flag set, if PGE is set > > in CR4. > > I know what PG_G does, Terry. My question is that if DISABLE_PG_G has > no effect on the _problems_ people are having. It can have an effect, if the problem is being exhibited on a P3 or an AMD processor, but not on a P4, unless it has 512M of memory; the jury is out on other memory sizes, after Matt Dillon's dynamic sizing changes (my own suggestion in this area was to conservatively not go overboard in allocating a multiplier of physical memory for page mappings, when doing so would push the space the mappings could cover well over the available physical address space, if you'll remember). I think the processor in the bug report that started this thread was an AMD K6? There really is a CPU bug, John, and the new FreeBSD locore.s code is triggering it. A stock FreeBSD 4.4, for example, will not exhibit this problem, on the same hardware. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message