From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933127AbXCMLsM (ORCPT ); Tue, 13 Mar 2007 07:48:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933134AbXCMLsM (ORCPT ); Tue, 13 Mar 2007 07:48:12 -0400 Received: from smtp.osdl.org ([65.172.181.24]:43209 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933127AbXCMLsL (ORCPT ); Tue, 13 Mar 2007 07:48:11 -0400 Date: Tue, 13 Mar 2007 04:47:56 -0800 From: Andrew Morton To: Nick Piggin Cc: clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [QUICKLIST 0/4] Arch independent quicklists V2 Message-Id: <20070313044756.b45649ac.akpm@linux-foundation.org> In-Reply-To: <45F68B4B.9020200@yahoo.com.au> References: <20070313071325.4920.82870.sendpatchset@schroedinger.engr.sgi.com> <20070313005334.853559ca.akpm@linux-foundation.org> <45F65ADA.9010501@yahoo.com.au> <20070313035250.f908a50e.akpm@linux-foundation.org> <45F685C6.8070806@yahoo.com.au> <20070313041551.565891b5.akpm@linux-foundation.org> <45F68B4B.9020200@yahoo.com.au> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.19; i686-pc-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 Tue, 13 Mar 2007 22:30:19 +1100 Nick Piggin wrote: > We don't actually have to zap_pte_range the entire page table in > order to free it (IIRC we used to have to, before the 4lpt patches). I'm trying to remember why we ever would have needed to zero out the pagetable pages if we're taking down the whole mm? Maybe it's because "oh, the arch wants to put this page into a quicklist to recycle it", which is all rather circular. It would be interesting to look at a) leave the page full of random garbage if we're releasing the whole mm and b) return it straight to the page allocator.