Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754497AbZKDDpK (ORCPT ); Tue, 3 Nov 2009 22:45:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754350AbZKDDpJ (ORCPT ); Tue, 3 Nov 2009 22:45:09 -0500 Received: from ozlabs.org ([203.10.76.45]:47301 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754014AbZKDDpI (ORCPT ); Tue, 3 Nov 2009 22:45:08 -0500 Date: Wed, 4 Nov 2009 14:22:42 +1100 From: David Gibson To: Benjamin Herrenschmidt Cc: Hugh Dickins , "linux-mm@kvack.org" , linuxppc-dev@lists.ozlabs.org, "linux-kernel@vger.kernel.org" Subject: Re: Filtering bits in set_pte_at() Message-ID: <20091104032242.GC27772@yookeroo.seuss> Mail-Followup-To: David Gibson , Benjamin Herrenschmidt , Hugh Dickins , "linux-mm@kvack.org" , linuxppc-dev@lists.ozlabs.org, "linux-kernel@vger.kernel.org" References: <1256957081.6372.344.camel@pasglop> <1257200367.7907.50.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1257200367.7907.50.camel@pasglop> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1645 Lines: 40 On Tue, Nov 03, 2009 at 09:19:27AM +1100, Benjamin Herrenschmidt wrote: > On Mon, 2009-11-02 at 13:27 +0000, Hugh Dickins wrote: > > On Sat, 31 Oct 2009, Benjamin Herrenschmidt wrote: > > > > > Hi folks ! > > > > > > So I have a little problem on powerpc ... :-) > > > > Thanks a lot for running this by us. > > Heh, I though you may have been bored :-) > > > I've not looked to see if there are more such issues in arch/powerpc > > itself, but those instances you mention are the only ones I managed > > to find: uses of update_mmu_cache() and that hugetlb_cow() one. > > Right, that's all I spotted so far > > > The hugetlb_cow() one involves not set_pte_at() but set_huge_pte_at(), > > so you'd want to change that too? And presumably set_pte_at_notify()? > > It all seems a lot of tedium, when so very few places are interested > > in the pte after they've set it. > > We need to change set_huge_pte_at() too. Currently, David fixed the > problem in a local tree by making hugetlb_cow() re-read the PTE . Well, actually I have another cleanup patch in the queue which makes set_huge_pte_at() equal to set_pte_at() on powerpc, and I was using that on the tree where this problem became apparent. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson -- 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/