Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262681AbVCCWTw (ORCPT ); Thu, 3 Mar 2005 17:19:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262676AbVCCWRh (ORCPT ); Thu, 3 Mar 2005 17:17:37 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:29883 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S262643AbVCCWOP (ORCPT ); Thu, 3 Mar 2005 17:14:15 -0500 Date: Thu, 3 Mar 2005 14:14:11 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Andrew Morton cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org Subject: Re: Page fault scalability patch V18: Drop first acquisition of ptl In-Reply-To: <20050303132011.7c80033d.akpm@osdl.org> Message-ID: References: <20050302174507.7991af94.akpm@osdl.org> <20050302185508.4cd2f618.akpm@osdl.org> <20050302201425.2b994195.akpm@osdl.org> <20050302205612.451d220b.akpm@osdl.org> <20050302222008.4910eb7b.akpm@osdl.org> <20050303132011.7c80033d.akpm@osdl.org> 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: 1031 Lines: 31 On Thu, 3 Mar 2005, Andrew Morton wrote: > Christoph Lameter wrote: > > > > On Wed, 2 Mar 2005, Andrew Morton wrote: > > > > > > This is not relevant since it only deals with file pages. > > > > > > OK. And CONFIG_DEBUG_PAGEALLOC? > > > > Its a debug feature that can be fixed if its broken. > > It's broken. > > A fix would be to restore the get_page() if CONFIG_DEBUG_PAGEALLOC. Not > particularly glorious.. Another fix would be to have a global variable "dontunmap" and have the map kernel function not change the pte. But this is also not the cleanest way. The problem with atomic operations is the difficulty of keeping state. The state must essentially all be bound to the atomic value replaced otherwise more extensive locking schemes are needed. - 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/