From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993052AbXDTRTH (ORCPT ); Fri, 20 Apr 2007 13:19:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993291AbXDTRTH (ORCPT ); Fri, 20 Apr 2007 13:19:07 -0400 Received: from holomorphy.com ([66.93.40.71]:42201 "EHLO holomorphy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993052AbXDTRTE (ORCPT ); Fri, 20 Apr 2007 13:19:04 -0400 Date: Fri, 20 Apr 2007 10:19:28 -0700 From: William Lee Irwin III To: Christoph Lameter Cc: Mel Gorman , linux-kernel@vger.kernel.org, Peter Zijlstra , Nick Piggin , Andi Kleen , Paul Jackson , Dave Chinner Subject: Re: [RFC 7/8] Enhance ramfs to support higher order pages Message-ID: <20070420171928.GA2986@holomorphy.com> References: <20070419163504.11948.58487.sendpatchset@schroedinger.engr.sgi.com> <20070419163540.11948.51549.sendpatchset@schroedinger.engr.sgi.com> <20070420134226.GA16878@skynet.ie> <20070420144726.GI31925@holomorphy.com> <20070420171118.GZ2986@holomorphy.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Apr 2007, William Lee Irwin III wrote: >> The core VM can do that but the hugetlb architectural code can't fall >> back to smaller page sizes. It also should not be put into a situation >> where it needs to do so given the semantics it must honor. On Fri, Apr 20, 2007 at 10:15:00AM -0700, Christoph Lameter wrote: > Wel we could potentially add a handle_pmd_fault to the vm...? Unconscionably foul. I guess x86-uber-alles pagetables in the core vm is the Linux way, though. On Fri, 20 Apr 2007, William Lee Irwin III wrote: >> Also, the final assertion is inaccurate. Fault handlers must instantiate >> pages of order mapping->order when faulting in a page of a file with >> a given pagecache size. The semantics of faulting and mmap()'ing are On Fri, Apr 20, 2007 at 10:15:00AM -0700, Christoph Lameter wrote: > Why? I agree that the page state of the higher order page must be updated > consistently but one can use a pte to map a 4k chunk of a higher > order page. Probably just terminological disagreement here. I was referring to allocating the higher-order page from the fault path here, not mapping it or a piece of it with a user pte. -- wli