From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752658AbXCMX6U (ORCPT ); Tue, 13 Mar 2007 19:58:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752660AbXCMX6U (ORCPT ); Tue, 13 Mar 2007 19:58:20 -0400 Received: from ozlabs.org ([203.10.76.45]:60722 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbXCMX6T (ORCPT ); Tue, 13 Mar 2007 19:58:19 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17911.14998.938879.432788@cargo.ozlabs.ibm.com> Date: Wed, 14 Mar 2007 10:58:14 +1100 From: Paul Mackerras To: Andrew Morton Cc: Nick Piggin , clameter@sgi.com, linux-mm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [QUICKLIST 0/4] Arch independent quicklists V2 In-Reply-To: <20070313035250.f908a50e.akpm@linux-foundation.org> 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> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > Plus, we can get in a situation where take a cache-cold, known-zero page > from the pte quicklist when there is a cache-hot, non-zero page sitting in > the page allocator. I suspect that zeroing the cache-hot page would take a > similar amount of time to a single miss agains the cache-cold page. That is certainly the case on powerpc. > I'm not saying that I _know_ that the quicklists are pointless, but I don't > think it's established that they are pointful. I don't see much point to them. For powerpc, I would rather grab an arbitrary page and zero it than get a page off a quicklist. > Maybe, dunno. It was apparently a win on powerpc many years ago. I had a My recollection was that it wasn't a win, but it was a long time ago... Paul.