From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754047AbaEFTL4 (ORCPT ); Tue, 6 May 2014 15:11:56 -0400 Received: from mail-bl2lp0209.outbound.protection.outlook.com ([207.46.163.209]:29559 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751595AbaEFTLy (ORCPT ); Tue, 6 May 2014 15:11:54 -0400 X-WSS-ID: 0N562NC-07-BT0-02 X-M-MSG: Message-ID: <536933E9.6040404@amd.com> Date: Tue, 6 May 2014 14:11:37 -0500 From: Suravee Suthikulanit User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Joerg Roedel CC: , , , Subject: Re: [PATCH] iommu/amd: Take mmap_sem when calling get_user_pages References: <1398724066-3730-1-git-send-email-suravee.suthikulpanit@amd.com> <20140506181438.GD12376@8bytes.org> In-Reply-To: <20140506181438.GD12376@8bytes.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:165.204.84.221;CTRY:US;IPV:NLI;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009001)(6009001)(428001)(24454002)(199002)(189002)(51704005)(377454003)(479174003)(87936001)(76482001)(99396002)(83506001)(46102001)(81542001)(97736001)(86362001)(81342001)(87266999)(54356999)(77096999)(4396001)(77982001)(50986999)(84676001)(65816999)(76176999)(2009001)(74502001)(31966008)(74662001)(19580405001)(83322001)(80316001)(92566001)(19580395003)(44976005)(85852003)(83072002)(80022001)(65806001)(79102001)(20776003)(47776003)(64706001)(23756003)(64126003)(36756003)(21056001)(68736004)(92726001)(101416001);DIR:OUT;SFP:1101;SCL:1;SRVR:BLUPR02MB113;H:atltwp01.amd.com;FPR:;MLV:sfv;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-Forefront-PRVS: 0203C93D51 Authentication-Results: spf=none (sender IP is 165.204.84.221) smtp.mailfrom=Suravee.Suthikulpanit@amd.com; X-OriginatorOrg: amd4.onmicrosoft.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/6/2014 1:14 PM, Joerg Roedel wrote: > On Mon, Apr 28, 2014 at 05:27:46PM -0500, Suthikulpanit, Suravee wrote: >> From: Jay Cornwall >> >> get_user_pages requires caller to hold a read lock on mmap_sem. > > Right, but can't we just switch to get_user_pages_fast instead? > > > Joerg > You're right. I think it can. Let me spin out another patch. Suravee