From owner-freebsd-bugs Tue Oct 31 6:30:10 2000 Delivered-To: freebsd-bugs@freebsd.org Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 6EB2637B4C5 for ; Tue, 31 Oct 2000 06:30:06 -0800 (PST) Received: (from gnats@localhost) by freefall.freebsd.org (8.9.3/8.9.2) id GAA61582; Tue, 31 Oct 2000 06:30:06 -0800 (PST) (envelope-from gnats@FreeBSD.org) Date: Tue, 31 Oct 2000 06:30:06 -0800 (PST) Message-Id: <200010311430.GAA61582@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: David Greenman Subject: Re: i386/22441: pmap_growkernel() is not effective at kernel vm limit of 0xffc00000 Reply-To: David Greenman Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org The following reply was made to PR i386/22441; it has been noted by GNATS. From: David Greenman To: carp@world.std.com Cc: freebsd-gnats-submit@FreeBSD.ORG Subject: Re: i386/22441: pmap_growkernel() is not effective at kernel vm limit of 0xffc00000 Date: Tue, 31 Oct 2000 06:23:19 -0800 >When called with a kernel vm limit of 0xffc00000, pamp_growkernel() >does not set-up the page mapping hardware because of an overflow. > >In this line: > > addr = (addr + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); > ( Line 1403 in $FreeBSD: src/sys/i386/i386/pmap.c,v 1.250.2.5 2000/08/05 00:39:08 peter Exp $) > >addr + PAGE_SIZE * NPTEPG overflows to zero when addr is 0xffc00000. I might not be understanding what you're doing exactly, but I should point out that the alternate page table map (APTmap) starts at 0xffc00000, so I don't see how you could ever use that area of virtual memory without serious problems. What am I missing? -DG David Greenman Co-founder, The FreeBSD Project - http://www.freebsd.org President, TeraSolutions, Inc. - http://www.terasolutions.com Pave the road of life with opportunities. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message