From owner-freebsd-current@FreeBSD.ORG Wed May 14 07:25:33 2003 Return-Path: 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 8B33637B405 for ; Wed, 14 May 2003 07:25:33 -0700 (PDT) Received: from mail.speakeasy.net (mail15.speakeasy.net [216.254.0.215]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0F73343FA3 for ; Wed, 14 May 2003 07:25:32 -0700 (PDT) (envelope-from jhb@FreeBSD.org) Received: (qmail 8091 invoked from network); 14 May 2003 14:25:31 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender )encrypted SMTP for ; 14 May 2003 14:25:31 -0000 Received: from laptop.baldwin.cx ([216.133.140.1]) by server.baldwin.cx (8.12.8/8.12.8) with ESMTP id h4EEPTp0031033; Wed, 14 May 2003 10:25:29 -0400 (EDT) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.4 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <3EC1CBC8.E263A9EF@mindspring.com> Date: Wed, 14 May 2003 10:25:37 -0400 (EDT) From: John Baldwin To: Terry Lambert cc: Robert Watson cc: re@FreeBSD.org cc: current@FreeBSD.org cc: Heiko Schaefer Subject: Re: 5.1-RELEASE TODO X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 May 2003 14:25:33 -0000 On 14-May-2003 Terry Lambert wrote: > The DISABLE_PG_G, as I said in a previous posting, works around > an order of operation problem that needs to clear PG in %CR0 > while it does it's thing, after which there's no problem with > enabling it. See "IA-32 Intel Architecture Software Developer's > Manual, Volume 3: System Programming Guide for more details on > PG_G, the PG bit in %CR0, and the effect on TLB flushing; look > specifically at Section 10.9 of "Memory Cache Control", which is > entitled "Invalidating The TRanslation Lookaside Buffers". > > Specifically, writing %CR3 doesn't invalidate pages with PG_G > set on them if PG is set in %CR0. Umm, Terry, that's the whole point of PGE. You don't flush entries from the TLB that are "global", i.e. shared among all processes and don't change. "Duh". Basically your suggestion would be an expensive hack equivalent to DISABLE_PG_G. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/