From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965920AbXCPUzs (ORCPT ); Fri, 16 Mar 2007 16:55:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965921AbXCPUzs (ORCPT ); Fri, 16 Mar 2007 16:55:48 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:44873 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S965920AbXCPUzr (ORCPT ); Fri, 16 Mar 2007 16:55:47 -0400 Date: Fri, 16 Mar 2007 13:55:45 -0700 (PDT) Message-Id: <20070316.135545.119242282.davem@davemloft.net> To: clameter@sgi.com Cc: andi@firstfloor.org, rostedt@goodmis.org, torvalds@linux-foundation.org, mbligh@mbligh.org, mingo@elte.hu, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, chrisw@sous-sol.org, rusty@rustcorp.com.au, glommer@gmail.com Subject: Re: [PATCH 00/18] Make common x86 arch area for i386 and x86_64 - Take 2 From: David Miller In-Reply-To: References: <20070316.134718.95058720.davem@davemloft.net> X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Christoph Lameter Date: Fri, 16 Mar 2007 13:52:18 -0700 (PDT) > Virtual mmap allows holes in the same way as page tables do. I don't want to take expensive TLB misses to lookup a page. Don't force a virtual mapping solution down my throat if that is not what I believe as a platform maintainer works best for me. TLB misses are extremely expensive on some platforms, that's why I try to make all the critical structures go through the 4MB locked TLB entry for the kernel image, or failing that the 4MB linear mappings at PAGE_OFFSET on sparc64.