Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030359AbVKCPy1 (ORCPT ); Thu, 3 Nov 2005 10:54:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030361AbVKCPy1 (ORCPT ); Thu, 3 Nov 2005 10:54:27 -0500 Received: from taurus.voltaire.com ([193.47.165.240]:13646 "EHLO taurus.voltaire.com") by vger.kernel.org with ESMTP id S1030359AbVKCPyZ (ORCPT ); Thu, 3 Nov 2005 10:54:25 -0500 Date: Thu, 3 Nov 2005 17:53:44 +0200 From: Gleb Natapov To: Hugh Dickins Cc: "Michael S. Tsirkin" , Benjamin Herrenschmidt , Petr Vandrovec , Nick Piggin , Badari Pulavarty , Linux Kernel Mailing List Subject: Re: Nick's core remove PageReserved broke vmware... Message-ID: <20051103155343.GG22185@minantech.com> References: <20051103151421.GD31134@mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-OriginalArrivalTime: 03 Nov 2005 15:54:24.0514 (UTC) FILETIME=[DCD96620:01C5E08E] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1071 Lines: 25 On Thu, Nov 03, 2005 at 03:37:44PM +0000, Hugh Dickins wrote: > > > I don't much want to add another path into copy_pte_range, actually > > > copying pages. If the process really wants DMA into such areas, > > > then it should contain the code for the child to COW them itself? > > > > How do you do that, say, for a stack page, or global data section? > > And why do you need to? > > You seem to be saying, actually DONTCOPY isn't enough of a solution, > we need something else instead. > DONTCOPY is a good solution for the problem it solves, but there are other problems :). One of them is what should we do if only part of the page is used for DMA and other part contains information needed by the forked child? We can copy such pages on fork or declare such state to be user error. I can live with both. -- Gleb. - 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/