Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761606AbXFIIKD (ORCPT ); Sat, 9 Jun 2007 04:10:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757481AbXFIIJq (ORCPT ); Sat, 9 Jun 2007 04:09:46 -0400 Received: from mtagate6.de.ibm.com ([195.212.29.155]:8882 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757063AbXFIIJo (ORCPT ); Sat, 9 Jun 2007 04:09:44 -0400 Message-ID: <466A6042.7030500@de.ibm.com> Date: Sat, 09 Jun 2007 10:09:38 +0200 From: Carsten Otte Reply-To: carsteno@de.ibm.com Organization: =?ISO-8859-1?Q?IBM_Deutschland_Entwicklung_GmbH=2CVor?= =?ISO-8859-1?Q?sitzender_des_Aufsichtsrats=3A_Johann_Weihen=2CGe?= =?ISO-8859-1?Q?sch=E4ftsf=FChrung=3A_Herbert_Kircher=2CSitz_der_?= =?ISO-8859-1?Q?Gesellschaft=3A_B=F6blingen=2CRegistergericht=3A_Amts?= =?ISO-8859-1?Q?gericht_Stuttgart=2C_HRB_243294?= User-Agent: Mozilla-Thunderbird 2.0.0.0 (X11/20070601) MIME-Version: 1.0 To: Justin Treon CC: carsteno@de.ibm.com, "\"JXrn\" Engel" , Christoph Hellwig , Jared Hulbert , Nick Piggin , Andrew Morton , richard.griffiths@windriver.com, Richard Griffiths , Linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.21] cramfs: add cramfs Linear XIP References: <337240.79058.qm@web59309.mail.re1.yahoo.com> In-Reply-To: <337240.79058.qm@web59309.mail.re1.yahoo.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 26 Justin Treon wrote: > --- Carsten Otte wrote: >> The nice thing about this approach is: we use page->count and rmap, >> both already exist and are perfectly suited for our purpose. >> The downside: We need mem_map[] struct page entries behind all memory >> segments. Nowerdays we can easily create those via vmem_map/sparsemem. > Can you give an example of the proper way to use sparsemem in this case? We use vmem_map on 390: - __segment_load[arch/s390/mm/extmem.c] calls add_shared_memory() to create struct page entries behind a segment - segment_unload (same file) calls remove_shared_memory() to remove parts of the mem_map array again - arch/s390/mm/vmem.c implements both callbacks As far as I know, this can also be archived with sparsemem. Unfortunately I don't have an example for sparsemem at hand, I would try to use sparse_add_one_section()[mm/sparse.c]. sorry, Carsten - 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/