From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from www.linux.org.uk (parcelfarce.linux.theplanet.co.uk [195.92.249.252]) by dsl2.external.hp.com (Postfix) with ESMTP id 5B8BF483E for ; Fri, 26 Sep 2003 08:30:55 -0600 (MDT) Received: from willy by www.linux.org.uk with local (Exim 4.22) id 1A2tcS-0001F1-3B; Fri, 26 Sep 2003 15:30:52 +0100 Date: Fri, 26 Sep 2003 15:30:52 +0100 From: Matthew Wilcox To: "David S. Miller" Cc: Matthew Wilcox , santosha@india.hp.com, sct@redhat.com, santosh.abraham@hp.com, randolph@tausq.org, parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] Fwd: Problems with raw interface. Message-ID: <20030926143052.GL24824@parcelfarce.linux.theplanet.co.uk> References: <20030926053805.63bda07a.davem@redhat.com> <200309261311.SAA27414@redsea.india.hp.com> <20030926055652.32ddbbc2.davem@redhat.com> <20030926132901.GJ24824@parcelfarce.linux.theplanet.co.uk> <20030926062143.20d85a72.davem@redhat.com> <20030926140948.GK24824@parcelfarce.linux.theplanet.co.uk> <20030926070450.603c5c33.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20030926070450.603c5c33.davem@redhat.com> Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: On Fri, Sep 26, 2003 at 07:04:50AM -0700, David S. Miller wrote: > On Fri, 26 Sep 2003 15:09:48 +0100 > Matthew Wilcox wrote: > > > > You have to find a way to walk all the address spaces to figure out > > > where the page is mapped. > > > > That's ridiculous. For a start, pages can't be mapped into multiple > > address spaces without being in the page cache. > > How in the world can anonymous pages work then? Of course anonymous > pages can be in multiple address spaces without being in the page > cache. How? By fork()? If so, that's not a problem -- the pages stay at the same address in both processes, and flushing one will flush any inherited pages. Otherwise you'll have to be more explicit. -- "It's not Hollywood. War is real, war is primarily not about defeat or victory, it is about death. I've seen thousands and thousands of dead bodies. Do you think I want to have an academic debate on this subject?" -- Robert Fisk