From owner-freebsd-current@FreeBSD.ORG Tue Jul 25 06:35:19 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org 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 B85F816A4E0 for ; Tue, 25 Jul 2006 06:35:19 +0000 (UTC) (envelope-from keichii@freebsd.org) Received: from mail.cps.utexas.edu (mail.cps.utexas.edu [128.83.188.195]) by mx1.FreeBSD.org (Postfix) with ESMTP id 54C8143D45 for ; Tue, 25 Jul 2006 06:35:19 +0000 (GMT) (envelope-from keichii@freebsd.org) Received: from [128.83.157.105] (dhcp-128-83-157-105.psy.utexas.edu [128.83.157.105]) by mail.cps.utexas.edu (8.13.1/8.13.1) with ESMTP id k6P6MUaa025521 for ; Tue, 25 Jul 2006 01:22:30 -0500 Message-ID: <44C5BBB4.8080102@freebsd.org> Date: Tue, 25 Jul 2006 01:35:32 -0500 From: "Michael C. Wu" User-Agent: Thunderbird 1.5.0.4 (Windows/20060516) MIME-Version: 1.0 To: freebsd-current@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: amd64 page fault situation X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Tue, 25 Jul 2006 06:35:19 -0000 Hi Everyone, I am wondering what we actually do in the following situation. Suppose that there is an op code on amd64 that calls for a 64bit word. This word crosses a page boundary. i.e. The first byte or 2 of the word is on the last part of the page, and the second part of the word is on the next page. Do we just have a TLB miss or page miss? I'd like to know what happens. There seems to be a good optimization opportunity here. Thanks, Michael