From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752669AbdBOVqm (ORCPT ); Wed, 15 Feb 2017 16:46:42 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:48674 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750806AbdBOVqj (ORCPT ); Wed, 15 Feb 2017 16:46:39 -0500 Date: Wed, 15 Feb 2017 13:46:27 -0800 From: Andrew Morton To: "Aneesh Kumar K.V" Cc: Rik van Riel , Mel Gorman , paulus@ozlabs.org, benh@kernel.crashing.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 2/2] powerpc/mm/autonuma: Switch ppc64 to its own implementeation of saved write Message-Id: <20170215134627.315dd734bd0000393a680cc9@linux-foundation.org> In-Reply-To: <1486609259-6796-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1486609259-6796-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1486609259-6796-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Feb 2017 08:30:59 +0530 "Aneesh Kumar K.V" wrote: > With this our protnone becomes a present pte with READ/WRITE/EXEC bit cleared. > By default we also set _PAGE_PRIVILEGED on such pte. This is now used to help > us identify a protnone pte that as saved write bit. For such pte, we will clear > the _PAGE_PRIVILEGED bit. The pte still remain non-accessible from both user > and kernel. I don't see how these patches differ from the ones which are presently in -mm. It helps to have a [0/n] email for a patch series and to put a version number in there as well. > +#define pte_mk_savedwrite pte_mk_savedwrite > +static inline pte_t pte_mk_savedwrite(pte_t pte) > +{ > + /* > + * Used by Autonuma subsystem to preserve the write bit > + * while marking the pte PROT_NONE. Only allow this > + * on PROT_NONE pte > + */ > + VM_BUG_ON((pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_RWX | _PAGE_PRIVILEGED)) != > + cpu_to_be64(_PAGE_PRESENT | _PAGE_PRIVILEGED)); > + return __pte(pte_val(pte) & ~_PAGE_PRIVILEGED); > +} > + > +#define pte_savedwrite pte_savedwrite > +static inline bool pte_savedwrite(pte_t pte) > +{ > + /* > + * Saved write ptes are prot none ptes that doesn't have > + * privileged bit sit. We mark prot none as one which has > + * present and pviliged bit set and RWX cleared. To mark > + * protnone which used to have _PAGE_WRITE set we clear > + * the privileged bit. > + */ > + return !(pte_raw(pte) & cpu_to_be64(_PAGE_RWX | _PAGE_PRIVILEGED)); > +} > + > static inline pte_t pte_mkdevmap(pte_t pte) > { > return __pte(pte_val(pte) | _PAGE_SPECIAL|_PAGE_DEVMAP); arch/powerpc/include/asm/book3s/64/pgtable.h doesn't have pte_mkdevmap(). What tree are you patching here?