From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Word-at-a-time dcache name accesses Date: Sat, 03 Mar 2012 08:12:42 -0800 Message-ID: References: <4F516811.8060800@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , Linux Kernel Mailing List , linux-fsdevel , Al Viro To: "H. Peter Anvin" Return-path: Received: from mga11.intel.com ([192.55.52.93]:44659 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751250Ab2CCQMh (ORCPT ); Sat, 3 Mar 2012 11:12:37 -0500 In-Reply-To: <4F516811.8060800@zytor.com> (H. Peter Anvin's message of "Fri, 02 Mar 2012 16:38:41 -0800") Sender: linux-fsdevel-owner@vger.kernel.org List-ID: "H. Peter Anvin" writes: > On 03/02/2012 03:46 PM, Linus Torvalds wrote: >> >> Comments? >> > > My biggest concern is what happens when this happens to be at the end of > mapped kernel memory and we overrun the page? A long time ago (AMD K7ish) we had hardware bugs to work around in this area. Overlapping into some PCI hole MMIO areas could cause obscure hangs. That is why I was always careful to not do that in any x86 library code. -Andi -- ak@linux.intel.com -- Speaking for myself only