From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751150AbVIUQuc (ORCPT ); Wed, 21 Sep 2005 12:50:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751131AbVIUQuc (ORCPT ); Wed, 21 Sep 2005 12:50:32 -0400 Received: from silver.veritas.com ([143.127.12.111]:33286 "EHLO silver.veritas.com") by vger.kernel.org with ESMTP id S1751150AbVIUQub (ORCPT ); Wed, 21 Sep 2005 12:50:31 -0400 Date: Wed, 21 Sep 2005 17:50:05 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Blaisorblade cc: Rik van Riel , Andrew Morton , LKML , Ingo Molnar Subject: Re: Remap_file_pages, RSS limits, security implications (was: Re: [uml-devel] Re: [RFC] [patch 0/18] remap_file_pages protection support (for UML), try 3) In-Reply-To: <200509211816.37512.blaisorblade@yahoo.it> Message-ID: References: <200508262023.29170.blaisorblade@yahoo.it> <200509201706.06852.blaisorblade@yahoo.it> <200509211816.37512.blaisorblade@yahoo.it> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 21 Sep 2005 16:50:30.0520 (UTC) FILETIME=[9361E780:01C5BECC] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 Sep 2005, Blaisorblade wrote: > > Other pages in the VMA may be unmapped, yes, but not freed. In fact, they're > kept in by the pagecache reference; try_to_unmap() (or better its caller, > shrink_list) will only actually free the page it asked for. Not freed in that pass, yes; but brought closer to being freed soon. > The only real "problem" is that we do ptep_clear_flush_young without > activating the page. And yes, *this* may penalize who holds a nonlinear VMA. > But this is probably fair, given that we're going to have trouble in freeing > those pages. Good point, I don't remember ever considering that. But agree it should work out fairly. > > mm/trash.c? I got quite excited, > What would that have meant? Trash is rubbish or garbage. Or if I trash my hotel room (not me!), I'd rip the washbasin off the wall, smash the mirror, throw the chair through the window, ... hmm, better stop this public fantasy. Hugh