From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932816Ab1JRP4Q (ORCPT ); Tue, 18 Oct 2011 11:56:16 -0400 Received: from mga11.intel.com ([192.55.52.93]:59254 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755739Ab1JRP4P (ORCPT ); Tue, 18 Oct 2011 11:56:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.69,366,1315206000"; d="scan'208";a="79290650" From: Andi Kleen To: Jerome Glisse Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org Subject: Re: IOMMU keeping mapping over long period of time References: <20111018154828.GA4201@homer.localdomain> Date: Tue, 18 Oct 2011 08:56:14 -0700 In-Reply-To: <20111018154828.GA4201@homer.localdomain> (Jerome Glisse's message of "Tue, 18 Oct 2011 11:48:28 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jerome Glisse writes: > > GPU for which we are interested have dma mask of 40bits at least, thus > they can work with high mem page. My main concern is when an iommu is > active, such amount of continuously mapped page might exhaust the iommu > address space. My understanding is that Intel & AMD iommu are capable of > growing their address space but is it somethings we can rely on ? I don't think relying on this is very wise. Better add some way to unmap when space is running short. -Andi