From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934071AbXHHQxr (ORCPT ); Wed, 8 Aug 2007 12:53:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759905AbXHHQxk (ORCPT ); Wed, 8 Aug 2007 12:53:40 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.142]:46009 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756384AbXHHQxj (ORCPT ); Wed, 8 Aug 2007 12:53:39 -0400 Subject: Re: [RFC][PATCH 1/5] pagemap: remove file header From: Dave Hansen To: Alan Cox Cc: Matt Mackall , linux-kernel@vger.kernel.org, serue@us.ibm.com, "ADAM G. LITKE [imap]" In-Reply-To: <1186590879.22283.99.camel@localhost> References: <20070807223300.9228E0E0@kernel> <20070808011620.GF30556@waste.org> <20070808023100.222c4d15@the-village.bc.nu> <1186590879.22283.99.camel@localhost> Content-Type: text/plain Date: Wed, 08 Aug 2007 09:53:35 -0700 Message-Id: <1186592015.22283.108.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-08-08 at 09:34 -0700, Dave Hansen wrote: > On Wed, 2007-08-08 at 02:31 +0100, Alan Cox wrote: > > The information needed to parse /proc/pid/pagemap can be stuck > > in /proc/pid/somewherelese. If we ever get page size variations and the > > like then /proc/pid/ is going to end up with that information anyway for > > ps and friends to use. > > We do at least have some of this with hugetlbfs. In fact, the current > pagemap code bugs out when it hits a huge page area: > > /home/dave/work/linux/2.6/22/lxc/mm/memory.c:117: bad pgd 1d0000e7. > > I'll look at fixing that. I figure we have three options: 1. ignore huge pages completely 2. teach the ->pte_entry handler that ptes can be different sizes, and pass the huge ptes into there 3. let the ->pmd_entry handler (or whatever level we've stuck the huge page entry in) handle it 4. create new handlers for large pages, like ->huge_pte_entry. This works for now, but what would we do if we have multiple/variable large page sizes? Any other thoughts? -- Dave