From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges Date: Fri, 29 Feb 2008 14:13:02 +0100 Message-ID: <20080229131302.GT8091@v2.random> References: <200802201008.49933.nickpiggin@yahoo.com.au> <20080228001104.GB8091@v2.random> <20080228005249.GF8091@v2.random> <20080228011020.GG8091@v2.random> <20080229005530.GO8091@v2.random> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Nick Piggin , steiner@sgi.com, Peter Zijlstra , linux-mm@kvack.org, Kanoj Sarcar , Roland Dreier , Steve Wise , linux-kernel@vger.kernel.org, Avi Kivity , kvm-devel@lists.sourceforge.net, daniel.blueman@quadrics.com, Robin Holt , general@lists.openfabrics.org, akpm@linux-foundation.org To: Christoph Lameter Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Thu, Feb 28, 2008 at 04:59:59PM -0800, Christoph Lameter wrote: > And thus the device driver may stop receiving data on a UP system? It will > never get the ack. Not sure to follow, sorry. My idea was: post the invalidate in the mmio region of the device smp_call_function() while (mmio device wait-bitflag is on); Instead of the current: smp_call_function() post the invalidate in the mmio region of the device while (mmio device wait-bitflag is on); To decrease the wait loop time. > invalidate_page_before/end could be realized as an > invalidate_range_begin/end on a page sized range? If we go this route, once you add support to xpmem, you'll have to make the anon_vma lock a mutex too, that would be fine with me though. The main reason invalidate_page exists, is to allow you to leave it as non-sleep-capable even after you make invalidate_range sleep capable, and to implement the mmu_rmap_notifiers sleep capable in all the paths that invalidate_page would be called. That was the strategy you had in your patch. I'll try to drop invalidate_page. I wonder if then you won't need the mmu_rmap_notifiers anymore. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/