Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262328AbUDEMpu (ORCPT ); Mon, 5 Apr 2004 08:45:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262339AbUDEMpu (ORCPT ); Mon, 5 Apr 2004 08:45:50 -0400 Received: from mail.shareable.org ([81.29.64.88]:59287 "EHLO mail.shareable.org") by vger.kernel.org with ESMTP id S262328AbUDEMmC (ORCPT ); Mon, 5 Apr 2004 08:42:02 -0400 Date: Mon, 5 Apr 2004 13:41:58 +0100 From: Jamie Lokier To: =?iso-8859-1?Q?J=F6rn?= Engel Cc: "Eric W. Biederman" , Pavel Machek , mj@ucw.cz, jack@ucw.cz, "Patrick J. LoPresti" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] cowlinks v2 Message-ID: <20040405124158.GD19842@mail.shareable.org> References: <20040402165440.GB24861@wohnheim.fh-wedel.de> <20040402180128.GA363@elf.ucw.cz> <20040402181707.GA28112@wohnheim.fh-wedel.de> <20040402182357.GB410@elf.ucw.cz> <20040402200921.GC653@mail.shareable.org> <20040402213933.GB246@elf.ucw.cz> <20040403010425.GJ653@mail.shareable.org> <20040403194344.GA5477@mail.shareable.org> <20040405083549.GD28924@wohnheim.fh-wedel.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20040405083549.GD28924@wohnheim.fh-wedel.de> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 30 J?rn Engel wrote: > Sharing the page cache is more important to me than sharing disk > space. Disk space is cheap, but increasing memory beyond 1GiB in my > notebook is not and 1GiB is too little, so memory is the real > constraint. Lucky you! I have 192MB, that's as much as it can take. > And it looks like Pavel already found the solution. Whenever doing > something fishy that would confuse the page cache, we > 1. lock > 2. invalidate page cache for all files belonging to that cow entity > 3. copyfile(), write(), or whatever > 4. unlock > > This is always possibly, because page cache for cow-files is never > read-write. If it was, we would have done 1-4 before and now have a > regular (non-cow) file. > > Did I miss something? Just some interesting indirection or substitution of address_space objects needed in the vmas, to map the right pages. -- Jamie - 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/