From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 44C1E6B0387 for ; Tue, 14 Feb 2017 00:56:04 -0500 (EST) Received: by mail-it0-f71.google.com with SMTP id 203so17675204ith.3 for ; Mon, 13 Feb 2017 21:56:04 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id 31si13031241ios.181.2017.02.13.21.56.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Feb 2017 21:56:03 -0800 (PST) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1E5nN1E137463 for ; Tue, 14 Feb 2017 00:56:03 -0500 Received: from e34.co.us.ibm.com (e34.co.us.ibm.com [32.97.110.152]) by mx0b-001b2d01.pphosted.com with ESMTP id 28kthtbd09-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 14 Feb 2017 00:56:03 -0500 Received: from localhost by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 13 Feb 2017 22:56:02 -0700 Subject: Re: [PATCH V2 1/2] mm/autonuma: Let architecture override how the write bit should be stashed in a protnone pte. References: <1487050314-3892-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1487050314-3892-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <87poilmien.fsf@concordia.ellerman.id.au> From: "Aneesh Kumar K.V" Date: Tue, 14 Feb 2017 11:25:48 +0530 MIME-Version: 1.0 In-Reply-To: <87poilmien.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Michael Ellerman , akpm@linux-foundation.org, Rik van Riel , Mel Gorman , paulus@ozlabs.org, benh@kernel.crashing.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org On Tuesday 14 February 2017 11:19 AM, Michael Ellerman wrote: > "Aneesh Kumar K.V" writes: > >> Autonuma preserves the write permission across numa fault to avoid taking >> a writefault after a numa fault (Commit: b191f9b106ea " mm: numa: preserve PTE >> write permissions across a NUMA hinting fault"). Architecture can implement >> protnone in different ways and some may choose to implement that by clearing Read/ >> Write/Exec bit of pte. Setting the write bit on such pte can result in wrong >> behaviour. Fix this up by allowing arch to override how to save the write bit >> on a protnone pte. > This is pretty obviously a nop on arches that don't implement the new > hooks, but it'd still be good to get an ack from someone in mm land > before I merge it. To get it apply cleanly you may need http://ozlabs.org/~akpm/mmots/broken-out/mm-autonuma-dont-use-set_pte_at-when-updating-protnone-ptes.patch http://ozlabs.org/~akpm/mmots/broken-out/mm-autonuma-dont-use-set_pte_at-when-updating-protnone-ptes-fix.patch They are strictly not needed after the saved write patch. But I didn't request to drop them, because the patch helps us to get closer to the goal of no ste_pte_at() call on present ptes. -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