Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932781AbZJLQUu (ORCPT ); Mon, 12 Oct 2009 12:20:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932771AbZJLQUt (ORCPT ); Mon, 12 Oct 2009 12:20:49 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:56007 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932763AbZJLQUt (ORCPT ); Mon, 12 Oct 2009 12:20:49 -0400 Date: Mon, 12 Oct 2009 17:13:28 +0100 From: Alan Cox To: David Woodhouse Cc: Linus Torvalds , "Rafael J. Wysocki" , Greg Kroah-Hartman , Linux Kernel Mailing List , Adrian Bunk , Andrew Morton , Natalie Protasevich Subject: Re: 2.6.32-rc4: Reported regressions from 2.6.31 Message-ID: <20091012171328.159a480a@lxorguk.ukuu.org.uk> In-Reply-To: <1255362962.32729.63.camel@macbook.infradead.org> References: <1255342738.24732.265.camel@macbook.infradead.org> <1255362962.32729.63.camel@macbook.infradead.org> X-Mailer: Claws Mail 3.7.2 (GTK+ 2.14.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1008 Lines: 21 > That involves allocating a _shitload_ of page tables for a 1:1 mapping > of all of physical memory. We used to do that to pander to broken > graphics drivers, and the AMD guys asked me to stop because it was > actually quite painful for them to do the same. SMM isn't going to be touching high pages. In fact I wouldn't be the least suprised if simply mapping the low 1MB including EBDA/ISA space and the ACPI reserved areas worked simply because if it touches any other RAM in SMM mode its going to be peeing over our memory spaces. And if I remember rightly the magic SMM remapped memory area is quite small (64K) and low down too plus not DMAable (because otherwise DMA in the real OS to the pages SMM aliases over will go kersplat if an SMM occurs) Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/