From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751927AbaEFSOn (ORCPT ); Tue, 6 May 2014 14:14:43 -0400 Received: from 8bytes.org ([85.214.48.195]:33053 "EHLO mail.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750859AbaEFSOm (ORCPT ); Tue, 6 May 2014 14:14:42 -0400 Date: Tue, 6 May 2014 20:14:39 +0200 From: Joerg Roedel To: suravee.suthikulpanit@amd.com Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kim.naru@amd.com, jay.cornwall@amd.com Subject: Re: [PATCH] iommu/amd: Take mmap_sem when calling get_user_pages Message-ID: <20140506181438.GD12376@8bytes.org> References: <1398724066-3730-1-git-send-email-suravee.suthikulpanit@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1398724066-3730-1-git-send-email-suravee.suthikulpanit@amd.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-DSPAM-Result: Whitelisted X-DSPAM-Processed: Tue May 6 20:14:40 2014 X-DSPAM-Confidence: 0.9987 X-DSPAM-Probability: 0.0000 X-DSPAM-Signature: 5369269020861716815794 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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