From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030520AbXCCW0b (ORCPT ); Sat, 3 Mar 2007 17:26:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030522AbXCCW0b (ORCPT ); Sat, 3 Mar 2007 17:26:31 -0500 Received: from smtp.osdl.org ([65.172.181.24]:47703 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030520AbXCCW0a (ORCPT ); Sat, 3 Mar 2007 17:26:30 -0500 Date: Sat, 3 Mar 2007 14:26:09 -0800 From: Andrew Morton To: Rik van Riel Cc: bert hubert , linux-kernel@vger.kernel.org Subject: Re: userspace pagecache management tool Message-Id: <20070303142609.d3bc9cc3.akpm@linux-foundation.org> In-Reply-To: <45E9F454.2080600@redhat.com> References: <20070303122935.f1ab0067.akpm@linux-foundation.org> <45E9DD4A.2060806@redhat.com> <20070303131204.6706a95c.akpm@linux-foundation.org> <45E9E910.2070804@redhat.com> <20070303214108.GA28961@outpost.ds9a.nl> <20070303141448.1ed70e6d.akpm@linux-foundation.org> <45E9F454.2080600@redhat.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 03 Mar 2007 17:19:00 -0500 Rik van Riel wrote: > > It is *not* a global instruction. It uses setenv, so the user's policy > > affects only the target process and its forked children. > > ... and all other processes accessing the same file(s)! > > Your library and the system calls may be limited to one process, > but the consequences are global. Yes. So what? If the user wants to go and evict libc.so from pagecache then he can do so - the kernel has provided syscalls with which this can be done for at least seven years. Bad user, shouldn't do that.