From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751723AbXCYQEJ (ORCPT ); Sun, 25 Mar 2007 12:04:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751725AbXCYQEJ (ORCPT ); Sun, 25 Mar 2007 12:04:09 -0400 Received: from waste.org ([66.93.16.53]:35206 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751717AbXCYQEH (ORCPT ); Sun, 25 Mar 2007 12:04:07 -0400 Date: Sun, 25 Mar 2007 10:51:27 -0500 From: Matt Mackall To: Peter Zijlstra Cc: Miklos Szeredi , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, William Lee Irwin III Subject: Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems Message-ID: <20070325155127.GR10459@waste.org> References: <1174824752.5149.28.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1174824752.5149.28.camel@lappy> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 25, 2007 at 02:12:32PM +0200, Peter Zijlstra wrote: > On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: > > From: Miklos Szeredi > > > > Dirty page accounting/limiting doesn't work for nonlinear mappings, so > > for non-ram backed filesystems emulate with linear mappings. This > > retains ABI compatibility with previous kernels at minimal code cost. > > > > All known users of nonlinear mappings actually use tmpfs, so this > > shouldn't have any negative effect. They do? I thought the whole point of nonlinear mappings was for mapping files bigger than the address space (eg. databases). Is Oracle instead using this to map >3G files on a tmpfs?? -- Mathematics is the supreme nostalgia of our time.