From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932833AbYEFUH5 (ORCPT ); Tue, 6 May 2008 16:07:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764391AbYEFUH1 (ORCPT ); Tue, 6 May 2008 16:07:27 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:36055 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763656AbYEFUH0 (ORCPT ); Tue, 6 May 2008 16:07:26 -0400 Date: Tue, 6 May 2008 13:06:20 -0700 (PDT) From: Linus Torvalds To: Hugh Dickins cc: Ingo Molnar , Jeff Chua , Thomas Gleixner , "H. Peter Anvin" , Gabriel C , Hans Rosenfeld , Arjan van de Ven , Nishanth Aravamudan , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] x86: fix PAE pmd_bad bootup warning In-Reply-To: Message-ID: References: <20080506124946.GA2146@elte.hu> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) 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 On Tue, 6 May 2008, Hugh Dickins wrote: > > Fix Hans' good observation that follow_page() will never find pmd_huge() > because that would have already failed the pmd_bad test: test pmd_huge in > between the pmd_none and pmd_bad tests. Tighten x86's pmd_huge() check? > No, once it's a hugepage entry, it can get quite far from a good pmd: for > example, PROT_NONE leaves it with only ACCESSED of the KERN_PGTABLE bits. I'd much rather have pdm_bad() etc fixed up instead, so that they do a more proper test (not thinking that a PSE page is bad, since it clearly isn't). And then, make them dependent on DEBUG_VM, because doing the proper test will be more expensive. Hmm? Linus