Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754225AbXJVDSu (ORCPT ); Sun, 21 Oct 2007 23:18:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751580AbXJVDSn (ORCPT ); Sun, 21 Oct 2007 23:18:43 -0400 Received: from twinlark.arctic.org ([207.29.250.54]:38080 "EHLO twinlark.arctic.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480AbXJVDSm (ORCPT ); Sun, 21 Oct 2007 23:18:42 -0400 Date: Sun, 21 Oct 2007 20:18:41 -0700 (PDT) From: dean gaudet To: Nick Piggin cc: Jeremy Fitzhardinge , David Chinner , xfs@oss.sgi.com, Xen-devel , Linux Kernel Mailing List , Mark Williamson , =?ISO-8859-15?Q?Morten_B=F8geskov?= , xfs-masters@oss.sgi.com Subject: Re: Interaction between Xen and XFS: stray RW mappings In-Reply-To: <200710151415.07248.nickpiggin@yahoo.com.au> Message-ID: References: <470FA7C3.90404@goop.org> <20071014225618.GN23367404@sgi.com> <4712A254.4090604@goop.org> <200710151415.07248.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 627 Lines: 15 On Mon, 15 Oct 2007, Nick Piggin wrote: > Yes, as Dave said, vmap (more specifically: vunmap) is very expensive > because it generally has to invalidate TLBs on all CPUs. why is that? ignoring 32-bit archs we have heaps of address space available... couldn't the kernel just burn address space and delay global TLB invalidate by some relatively long time (say 1 second)? -dean - 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/