Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754595AbZIHOOu (ORCPT ); Tue, 8 Sep 2009 10:14:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754494AbZIHOOt (ORCPT ); Tue, 8 Sep 2009 10:14:49 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52553 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753788AbZIHOOt (ORCPT ); Tue, 8 Sep 2009 10:14:49 -0400 Date: Tue, 8 Sep 2009 07:13:55 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Nick Piggin cc: Hugh Dickins , Andrew Morton , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 7/8] mm: reinstate ZERO_PAGE In-Reply-To: <20090908073119.GA29902@wotan.suse.de> Message-ID: References: <20090908073119.GA29902@wotan.suse.de> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 728 Lines: 19 On Tue, 8 Sep 2009, Nick Piggin wrote: > > Without looking closely, why is it a big problem to have a > !HAVE PTE SPECIAL case? Couldn't it just be a check for > pfn == zero_pfn that is conditionally compiled away for pte > special architectures anyway? At least traditionally, there wasn't a single zero_pfn, but multiple (for VIPT caches that have performance issues with aliases). But yeah, we could check just the pfn number, and allow any architecture to do it. Linus -- 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/