From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=/1XN=2I=vger.kernel.org=linux-mips-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS
	autolearn=no autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
	by smtp.lore.kernel.org (Postfix) with ESMTP id AF16BC43603
	for <linux-mips@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:27 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 75ACF206CB
	for <linux-mips@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:27 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;
	s=default; t=1576683027;
	bh=VoDZA28QIA8ZuEkr4fUTI8rp1iZfr1x38wiooqnNZsw=;
	h=To:Subject:Date:From:Cc:In-Reply-To:References:List-ID:From;
	b=fFUNO5SGZYq5HJmF3kC7RFzuOB7LvqWnTx5q0OEZaAY8DM1crpCaz7HAN1OzxQXyw
	 50ivjEZJ3UqrxLXfFVoaVVFLn7JAHf7cGyfbr4heGff/papQZ2tTepIju6DqRtqezr
	 P5LlQoDrMQ+5f9TwUSMZDA35AtSc1r5qa8GGAlpk=
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727189AbfLRPa1 (ORCPT <rfc822;linux-mips@archiver.kernel.org>);
        Wed, 18 Dec 2019 10:30:27 -0500
Received: from inca-roads.misterjones.org ([213.251.177.50]:35235 "EHLO
        inca-roads.misterjones.org" rhost-flags-OK-OK-OK-OK)
        by vger.kernel.org with ESMTP id S1727001AbfLRPa1 (ORCPT
        <rfc822;linux-mips@vger.kernel.org>);
        Wed, 18 Dec 2019 10:30:27 -0500
Received: from www-data by cheepnis.misterjones.org with local (Exim 4.80)
        (envelope-from <maz@kernel.org>)
        id 1ihbH2-0003tk-7u; Wed, 18 Dec 2019 16:30:04 +0100
To:     James Morse <james.morse@arm.com>
Subject: Re: [PATCH 7/7] KVM: arm/arm64: Elide CMOs when unmapping a range
X-PHP-Originating-Script: 0:main.inc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
 format=flowed
Content-Transfer-Encoding: 7bit
Date:   Wed, 18 Dec 2019 15:30:04 +0000
From:   Marc Zyngier <maz@kernel.org>
Cc:     Julien Thierry <julien.thierry.kdev@gmail.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        James Hogan <jhogan@kernel.org>,
        Paul Mackerras <paulus@ozlabs.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        =?UTF-8?Q?Ra?= =?UTF-8?Q?dim_Kr=C4=8Dm=C3=A1=C5=99?= 
        <rkrcmar@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <kvmarm@lists.cs.columbia.edu>, <linux-mips@vger.kernel.org>,
        <kvm-ppc@vger.kernel.org>, <kvm@vger.kernel.org>
In-Reply-To: <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
References: <20191213182503.14460-1-maz@kernel.org>
 <20191213182503.14460-8-maz@kernel.org>
 <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
Message-ID: <de462fe29fb40fb1644e6a071e6c0c69@www.loen.fr>
X-Sender: maz@kernel.org
User-Agent: Roundcube Webmail/0.7.2
X-SA-Exim-Connect-IP: <locally generated>
X-SA-Exim-Rcpt-To: james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, jhogan@kernel.org, paulus@ozlabs.org, pbonzini@redhat.com, rkrcmar@redhat.com, sean.j.christopherson@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
X-SA-Exim-Mail-From: maz@kernel.org
X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false
Sender: linux-mips-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-mips.vger.kernel.org>
X-Mailing-List: linux-mips@vger.kernel.org

Hi James,

On 2019-12-18 15:07, James Morse wrote:
> Hi Marc,
>
> On 13/12/2019 18:25, Marc Zyngier wrote:
>> If userspace issues a munmap() on a set of pages, there is no
>> expectation that the pages are cleaned to the PoC.
>
> (Pedantry: Clean and invalidate. If the guest wrote through a device
> mapping, we ditch any clean+stale lines with this path, meaning 
> swapout
> saves the correct values)

Indeed.

>> So let's
>> not do more work than strictly necessary, and set the magic
>> flag that avoids CMOs in this case.
>
> I think this assumes the pages went from anonymous->free, so no-one
> cares about the contents.
>
> If the pages are backed by a file, won't dirty pages will still get
> written back before the page is free? (e.g. EFI flash 'file' mmap()ed 
> in)

I believe so. Is that a problem?

> What if this isn't the only mapping of the page? Can't it be swapped
> out from another VMA? (tenuous example, poor man's memory mirroring?)

Swap-out wouldn't trigger this code path, as it would use a different
MMU notifier event (MMU_NOTIFY_CLEAR vs MMU_NOTIFY_UNMAP), I believe.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=uTqP=2I=lists.cs.columbia.edu=kvmarm-bounces@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.0 required=3.0 tests=MAILING_LIST_MULTI,
	SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 797EFC43603
	for <kvmarm@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:29 +0000 (UTC)
Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253])
	by mail.kernel.org (Postfix) with ESMTP id 0A782206CB
	for <kvmarm@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:28 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0A782206CB
Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org
Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu
Received: from localhost (localhost [127.0.0.1])
	by mm01.cs.columbia.edu (Postfix) with ESMTP id 76C804A65C;
	Wed, 18 Dec 2019 10:30:28 -0500 (EST)
X-Virus-Scanned: at lists.cs.columbia.edu
Received: from mm01.cs.columbia.edu ([127.0.0.1])
	by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id VbU87L7SFQxt; Wed, 18 Dec 2019 10:30:27 -0500 (EST)
Received: from mm01.cs.columbia.edu (localhost [127.0.0.1])
	by mm01.cs.columbia.edu (Postfix) with ESMTP id 846144A4CD;
	Wed, 18 Dec 2019 10:30:27 -0500 (EST)
Received: from localhost (localhost [127.0.0.1])
 by mm01.cs.columbia.edu (Postfix) with ESMTP id 5CDCC4A4CD
 for <kvmarm@lists.cs.columbia.edu>; Wed, 18 Dec 2019 10:30:26 -0500 (EST)
X-Virus-Scanned: at lists.cs.columbia.edu
Received: from mm01.cs.columbia.edu ([127.0.0.1])
 by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024)
 with ESMTP id Vcq-s0rlBiST for <kvmarm@lists.cs.columbia.edu>;
 Wed, 18 Dec 2019 10:30:25 -0500 (EST)
Received: from inca-roads.misterjones.org (inca-roads.misterjones.org
 [213.251.177.50])
 by mm01.cs.columbia.edu (Postfix) with ESMTPS id 468884A483
 for <kvmarm@lists.cs.columbia.edu>; Wed, 18 Dec 2019 10:30:25 -0500 (EST)
Received: from www-data by cheepnis.misterjones.org with local (Exim 4.80)
 (envelope-from <maz@kernel.org>)
 id 1ihbH2-0003tk-7u; Wed, 18 Dec 2019 16:30:04 +0100
To: James Morse <james.morse@arm.com>
Subject: Re: [PATCH 7/7] KVM: arm/arm64: Elide CMOs when unmapping a range
X-PHP-Originating-Script: 0:main.inc
MIME-Version: 1.0
Date: Wed, 18 Dec 2019 15:30:04 +0000
From: Marc Zyngier <maz@kernel.org>
In-Reply-To: <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
References: <20191213182503.14460-1-maz@kernel.org>
 <20191213182503.14460-8-maz@kernel.org>
 <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
Message-ID: <de462fe29fb40fb1644e6a071e6c0c69@www.loen.fr>
X-Sender: maz@kernel.org
User-Agent: Roundcube Webmail/0.7.2
X-SA-Exim-Connect-IP: <locally generated>
X-SA-Exim-Rcpt-To: james.morse@arm.com, julien.thierry.kdev@gmail.com,
 suzuki.poulose@arm.com, jhogan@kernel.org, paulus@ozlabs.org,
 pbonzini@redhat.com, rkrcmar@redhat.com, sean.j.christopherson@intel.com,
 vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com,
 joro@8bytes.org, linux-arm-kernel@lists.infradead.org,
 kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
 kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
X-SA-Exim-Mail-From: maz@kernel.org
X-SA-Exim-Scanned: No (on cheepnis.misterjones.org);
 SAEximRunCond expanded to false
Cc: kvm-ppc@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>,
 kvm@vger.kernel.org, James Hogan <jhogan@kernel.org>,
 Joerg Roedel <joro@8bytes.org>, linux-mips@vger.kernel.org,
 Sean Christopherson <sean.j.christopherson@intel.com>,
 Paul Mackerras <paulus@ozlabs.org>, linux-arm-kernel@lists.infradead.org,
 Paolo Bonzini <pbonzini@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>,
 kvmarm@lists.cs.columbia.edu, Jim Mattson <jmattson@google.com>
X-BeenThere: kvmarm@lists.cs.columbia.edu
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Where KVM/ARM decisions are made <kvmarm.lists.cs.columbia.edu>
List-Unsubscribe: <https://lists.cs.columbia.edu/mailman/options/kvmarm>,
 <mailto:kvmarm-request@lists.cs.columbia.edu?subject=unsubscribe>
List-Archive: <https://lists.cs.columbia.edu/pipermail/kvmarm>
List-Post: <mailto:kvmarm@lists.cs.columbia.edu>
List-Help: <mailto:kvmarm-request@lists.cs.columbia.edu?subject=help>
List-Subscribe: <https://lists.cs.columbia.edu/mailman/listinfo/kvmarm>,
 <mailto:kvmarm-request@lists.cs.columbia.edu?subject=subscribe>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Errors-To: kvmarm-bounces@lists.cs.columbia.edu
Sender: kvmarm-bounces@lists.cs.columbia.edu

Hi James,

On 2019-12-18 15:07, James Morse wrote:
> Hi Marc,
>
> On 13/12/2019 18:25, Marc Zyngier wrote:
>> If userspace issues a munmap() on a set of pages, there is no
>> expectation that the pages are cleaned to the PoC.
>
> (Pedantry: Clean and invalidate. If the guest wrote through a device
> mapping, we ditch any clean+stale lines with this path, meaning 
> swapout
> saves the correct values)

Indeed.

>> So let's
>> not do more work than strictly necessary, and set the magic
>> flag that avoids CMOs in this case.
>
> I think this assumes the pages went from anonymous->free, so no-one
> cares about the contents.
>
> If the pages are backed by a file, won't dirty pages will still get
> written back before the page is free? (e.g. EFI flash 'file' mmap()ed 
> in)

I believe so. Is that a problem?

> What if this isn't the only mapping of the page? Can't it be swapped
> out from another VMA? (tenuous example, poor man's memory mirroring?)

Swap-out wouldn't trigger this code path, as it would use a different
MMU notifier event (MMU_NOTIFY_CLEAR vs MMU_NOTIFY_UNMAP), I believe.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=1Cen=2I=lists.infradead.org=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no
	autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 79404C43603
	for <infradead-linux-arm-kernel@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:32 +0000 (UTC)
Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by mail.kernel.org (Postfix) with ESMTPS id 3EAE7206CB
	for <infradead-linux-arm-kernel@archiver.kernel.org>; Wed, 18 Dec 2019 15:30:32 +0000 (UTC)
Authentication-Results: mail.kernel.org;
	dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qWx+G/bF"
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3EAE7206CB
Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org
Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
	d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:
	Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive:
	List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:From:Date:
	MIME-Version:Subject:To:Reply-To:Content-ID:Content-Description:Resent-Date:
	Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner;
	 bh=atc5DbzXCpCqy/WS/H+sTp5htc0Ug2y4IoAOZYMGdqY=; b=qWx+G/bFQJaT8zUjduRbN/jDp
	60vVvSGxK06b2sWyyYHhROK0CX45wZD5QtO6aTOAoH4ylAsCltfOGts/4YU4qvwXu7KyjsB6U1FdS
	sRsRtA6bQgv4ZqeYE7LDXb9BoZoHVilpfHHn85oufD/t5tCny2t+KX0tTWim7xnI1dwsrz57AdKBS
	YvrskYN3tT/dQrDLHGH5QryF/urm3G5q5ZoY7Dvc7CmkBaXwJfcUEinerPnkL2pmVquelD55+LyIf
	z66+IdHSNe99XHEg0dohoqu9LQv7zWSNRY2tvbBWEkQl7NsGDo7C1kcUSNKiwYl+nuDO3MLvYosg8
	8u/qUEWKw==;
Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org)
	by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux))
	id 1ihbHN-00015A-H4; Wed, 18 Dec 2019 15:30:25 +0000
Received: from inca-roads.misterjones.org ([213.251.177.50])
 by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux))
 id 1ihbHK-00014c-RX
 for linux-arm-kernel@lists.infradead.org; Wed, 18 Dec 2019 15:30:24 +0000
Received: from www-data by cheepnis.misterjones.org with local (Exim 4.80)
 (envelope-from <maz@kernel.org>)
 id 1ihbH2-0003tk-7u; Wed, 18 Dec 2019 16:30:04 +0100
To: James Morse <james.morse@arm.com>
Subject: Re: [PATCH 7/7] KVM: arm/arm64: Elide CMOs when unmapping a range
X-PHP-Originating-Script: 0:main.inc
MIME-Version: 1.0
Date: Wed, 18 Dec 2019 15:30:04 +0000
From: Marc Zyngier <maz@kernel.org>
In-Reply-To: <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
References: <20191213182503.14460-1-maz@kernel.org>
 <20191213182503.14460-8-maz@kernel.org>
 <0c832b27-7041-a6c8-31c0-d71a25c6f5b8@arm.com>
Message-ID: <de462fe29fb40fb1644e6a071e6c0c69@www.loen.fr>
X-Sender: maz@kernel.org
User-Agent: Roundcube Webmail/0.7.2
X-SA-Exim-Connect-IP: <locally generated>
X-SA-Exim-Rcpt-To: james.morse@arm.com, julien.thierry.kdev@gmail.com,
 suzuki.poulose@arm.com, jhogan@kernel.org, paulus@ozlabs.org,
 pbonzini@redhat.com, rkrcmar@redhat.com, sean.j.christopherson@intel.com,
 vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com,
 joro@8bytes.org, linux-arm-kernel@lists.infradead.org,
 kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
 kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
X-SA-Exim-Mail-From: maz@kernel.org
X-SA-Exim-Scanned: No (on cheepnis.misterjones.org);
 SAEximRunCond expanded to false
X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 
X-CRM114-CacheID: sfid-20191218_073023_038316_93D2DCE3 
X-CRM114-Status: GOOD (  10.99  )
X-BeenThere: linux-arm-kernel@lists.infradead.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <linux-arm-kernel.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-arm-kernel>, 
 <mailto:linux-arm-kernel-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-arm-kernel/>
List-Post: <mailto:linux-arm-kernel@lists.infradead.org>
List-Help: <mailto:linux-arm-kernel-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-arm-kernel>, 
 <mailto:linux-arm-kernel-request@lists.infradead.org?subject=subscribe>
Cc: kvm-ppc@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>,
 kvm@vger.kernel.org,
 =?UTF-8?Q?Ra?= =?UTF-8?Q?dim_Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>,
 James Hogan <jhogan@kernel.org>, Joerg Roedel <joro@8bytes.org>,
 Suzuki K Poulose <suzuki.poulose@arm.com>, linux-mips@vger.kernel.org,
 Sean Christopherson <sean.j.christopherson@intel.com>,
 Paul Mackerras <paulus@ozlabs.org>, linux-arm-kernel@lists.infradead.org,
 Paolo Bonzini <pbonzini@redhat.com>, Vitaly Kuznetsov <vkuznets@redhat.com>,
 kvmarm@lists.cs.columbia.edu, Julien Thierry <julien.thierry.kdev@gmail.com>,
 Jim Mattson <jmattson@google.com>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org>
Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org

Hi James,

On 2019-12-18 15:07, James Morse wrote:
> Hi Marc,
>
> On 13/12/2019 18:25, Marc Zyngier wrote:
>> If userspace issues a munmap() on a set of pages, there is no
>> expectation that the pages are cleaned to the PoC.
>
> (Pedantry: Clean and invalidate. If the guest wrote through a device
> mapping, we ditch any clean+stale lines with this path, meaning 
> swapout
> saves the correct values)

Indeed.

>> So let's
>> not do more work than strictly necessary, and set the magic
>> flag that avoids CMOs in this case.
>
> I think this assumes the pages went from anonymous->free, so no-one
> cares about the contents.
>
> If the pages are backed by a file, won't dirty pages will still get
> written back before the page is free? (e.g. EFI flash 'file' mmap()ed 
> in)

I believe so. Is that a problem?

> What if this isn't the only mapping of the page? Can't it be swapped
> out from another VMA? (tenuous example, poor man's memory mirroring?)

Swap-out wouldn't trigger this code path, as it would use a different
MMU notifier event (MMU_NOTIFY_CLEAR vs MMU_NOTIFY_UNMAP), I believe.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel