Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932423AbVIZHVG (ORCPT ); Mon, 26 Sep 2005 03:21:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932424AbVIZHVG (ORCPT ); Mon, 26 Sep 2005 03:21:06 -0400 Received: from gold.veritas.com ([143.127.12.110]:45890 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S932423AbVIZHVF (ORCPT ); Mon, 26 Sep 2005 03:21:05 -0400 Date: Mon, 26 Sep 2005 08:20:35 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Andrew Morton cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 04/21] mm: zap_pte_range dont dirty anon In-Reply-To: <20050925231424.6c08bc8a.akpm@osdl.org> Message-ID: References: <20050925152630.75560571.akpm@osdl.org> <20050925231424.6c08bc8a.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 26 Sep 2005 07:21:04.0743 (UTC) FILETIME=[DB0ECF70:01C5C26A] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 600 Lines: 20 On Sun, 25 Sep 2005, Andrew Morton wrote: > > mmap(MAP_ANONYMOUS|MAP_SHARED) > fork() > swapout > swapin > swapoff > > Now we have two mm's sharing a clean, non-cowable, non-swapcache anonymous > page, no? No, MAP_ANONYMOUS|MAP_SHARED gives you a tmpfs object via shmem_zero_setup: all those pages are shared file pages, not PageAnon at all. Hugh - 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/