From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 30 Jan 2008 20:34:01 -0600 From: Robin Holt 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: Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: > 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org