From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f199.google.com (mail-wj0-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id 353D94405BD for ; Wed, 15 Feb 2017 21:13:00 -0500 (EST) Received: by mail-wj0-f199.google.com with SMTP id h7so692171wjy.6 for ; Wed, 15 Feb 2017 18:13:00 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id u43si7287379wrb.327.2017.02.15.18.12.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Feb 2017 18:12:58 -0800 (PST) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1G23i3D075473 for ; Wed, 15 Feb 2017 21:12:57 -0500 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0b-001b2d01.pphosted.com with ESMTP id 28n1m0k6xy-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 15 Feb 2017 21:12:57 -0500 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 15 Feb 2017 19:12:56 -0700 Subject: Re: [PATCH 2/2] powerpc/mm/autonuma: Switch ppc64 to its own implementeation of saved write 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> <20170215134627.315dd734bd0000393a680cc9@linux-foundation.org> From: "Aneesh Kumar K.V" Date: Thu, 16 Feb 2017 07:42:46 +0530 MIME-Version: 1.0 In-Reply-To: <20170215134627.315dd734bd0000393a680cc9@linux-foundation.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton 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 On Thursday 16 February 2017 03:16 AM, Andrew Morton wrote: > 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? > > I did post a V2 of this for which you replied https://lkml.kernel.org/r/20170214162008.bd592c747fc5e167c10ce7b8@linux-foundation.org I actually found the issue with this patch. I will be sending V3 after more testing. -aneesh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org