Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932436AbXAWD2p (ORCPT ); Mon, 22 Jan 2007 22:28:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932694AbXAWD2p (ORCPT ); Mon, 22 Jan 2007 22:28:45 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:49177 "EHLO omx1.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932436AbXAWD2o (ORCPT ); Mon, 22 Jan 2007 22:28:44 -0500 Date: Mon, 22 Jan 2007 19:28:01 -0800 (PST) From: Christoph Lameter To: Balbir Singh cc: Andrea Arcangeli , Niki Hammler , linux-kernel@vger.kernel.org, Vaidyanathan Srinivasan Subject: Re: Why active list and inactive list? In-Reply-To: <45B57E73.3000307@in.ibm.com> Message-ID: References: <45B55286.5060909@nobaq.net> <20070123003939.GY13798@opteron.random> <45B56575.10807@in.ibm.com> <45B57E73.3000307@in.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 870 Lines: 19 On Tue, 23 Jan 2007, Balbir Singh wrote: > When you unmap or map, you need to touch the pte entries and know the > pages involved, so shouldn't be equivalent to a list_del and list_add > for each page impacted by the map/unmap operation? When you unmap and map you must currently get exclusive access to the cachelines of the pte and the cacheline of the page struct. If we use a list_move on page->lru then we have would have to update pointers in up to 4 other page structs. Thus we need exclusive access to 4 additional cachelines. This triples the number of cachelines touched. Instead of 2 cachelines we need 6. - 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/