Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760305AbYAaCfe (ORCPT ); Wed, 30 Jan 2008 21:35:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755032AbYAaCfS (ORCPT ); Wed, 30 Jan 2008 21:35:18 -0500 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:35069 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755101AbYAaCeD (ORCPT ); Wed, 30 Jan 2008 21:34:03 -0500 Date: Wed, 30 Jan 2008 20:34:01 -0600 From: Robin Holt To: Christoph Lameter Cc: Andrea Arcangeli , Nick Piggin , Peter Zijlstra , linux-mm@kvack.org, Benjamin Herrenschmidt , steiner@sgi.com, linux-kernel@vger.kernel.org, Avi Kivity , kvm-devel@lists.sourceforge.net, daniel.blueman@quadrics.com, Robin Holt , Hugh Dickins Subject: Re: [kvm-devel] [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges Message-ID: <20080131023401.GY26420@sgi.com> References: <20080130000039.GA7233@v2.random> <20080130161123.GS26420@sgi.com> <20080130170451.GP7233@v2.random> <20080130173009.GT26420@sgi.com> <20080130182506.GQ7233@v2.random> <20080130235214.GC7185@v2.random> <20080131003434.GE7185@v2.random> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 669 Lines: 16 > Well the GRU uses follow_page() instead of get_user_pages. Performance is > a major issue for the GRU. Worse, the GRU takes its TLB faults from within an interrupt so we use follow_page to prevent going to sleep. That said, I think we could probably use follow_page() with FOLL_GET set to accomplish the requirements of mmu_notifier invalidate_range call. Doesn't look too promising for hugetlb pages. Thanks, Robin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/