From owner-freebsd-current Mon Jan 27 15:59:37 2003 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 8558237B401 for ; Mon, 27 Jan 2003 15:59:36 -0800 (PST) Received: from heron.mail.pas.earthlink.net (heron.mail.pas.earthlink.net [207.217.120.189]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1DB7A43F43 for ; Mon, 27 Jan 2003 15:59:36 -0800 (PST) (envelope-from tlambert2@mindspring.com) Received: from pool0350.cvx22-bradley.dialup.earthlink.net ([209.179.199.95] helo=mindspring.com) by heron.mail.pas.earthlink.net with asmtp (SSLv3:RC4-MD5:128) (Exim 3.33 #1) id 18dJA4-0000gl-00; Mon, 27 Jan 2003 15:59:33 -0800 Message-ID: <3E35C76E.ACE90A92@mindspring.com> Date: Mon, 27 Jan 2003 15:57:34 -0800 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Vincent Poy Cc: Eric Jones , walt , freebsd-current@FreeBSD.ORG Subject: Re: Options MAXMEM added to GENERIC kernel config causes kernelpanicin -current References: <20030126232934.T3206-100000@oahu.WURLDLINK.NET> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-ELNK-Trace: b1a02af9316fbb217a47c185c03b154d40683398e744b8a4c8111b2adf714153c2ac0908d78fee9c350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c 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 Vincent Poy wrote: > > > MAXMEM is useful for testing configurations with less memory, > > > without having to open up your box and yank SIMMs, or to have > > > a bunch of different sized pairs of SIMMs lying around. > > > > For uses such as testing I can understand, but I don't see a use under > > normal conditions, at least on newer systems. I haven't dug into the > > source yet today, but there must be a reason why ACPI doesn't play nice > > on certain systems when MAXMEM is specified. > > > > I wonder if it is just AMD systems? Mine's a 900MHz Duron, and IIRC I > > think someone else in earlier in the thread was using an AMD also. > > I posted the original thread and can say the problem occurs on > both PII366 notebook, P4m-2Ghz, P4-1.7Ghz as well as PIII1Ghz systems and > various AMD Athlon XP's. This is a well known problem with the TLB implementation; the answer is that, were you to yank out real physical memory, so that you had the same amount of memory as your were telling the machine you had, you would end up with the same problem. In other words, the setting is exposing a bug in FreeBSD, and this is what it's supposed to be doing, so please leave it alone in the source code, so that someone who wants to fix it can reproduce the problem locally on their machine. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message