From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753454Ab0A1Dtq (ORCPT ); Wed, 27 Jan 2010 22:49:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752836Ab0A1Dtp (ORCPT ); Wed, 27 Jan 2010 22:49:45 -0500 Received: from relay2.sgi.com ([192.48.179.30]:38107 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751854Ab0A1Dtp (ORCPT ); Wed, 27 Jan 2010 22:49:45 -0500 Date: Wed, 27 Jan 2010 21:49:44 -0600 From: Robin Holt To: Andrea Arcangeli Cc: Robin Holt , Jack Steiner , cl@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] - Fix unmap_vma() bug related to mmu_notifiers Message-ID: <20100128034943.GH6616@sgi.com> References: <20100125174556.GA23003@sgi.com> <20100125190052.GF5756@random.random> <20100125211033.GA24272@sgi.com> <20100125211615.GH5756@random.random> <20100126212904.GE6653@sgi.com> <20100126213853.GY30452@random.random> <20100128031841.GG6616@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100128031841.GG6616@sgi.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 27, 2010 at 09:18:42PM -0600, Robin Holt wrote: > On Tue, Jan 26, 2010 at 10:38:53PM +0100, Andrea Arcangeli wrote: > > On Tue, Jan 26, 2010 at 03:29:04PM -0600, Robin Holt wrote: > > > On Mon, Jan 25, 2010 at 10:16:15PM +0100, Andrea Arcangeli wrote: > > > > The old patches are in my ftp area, they should still apply, you > > > > should concentrate testing with those additional ones applied, then it > > > > will work for xpmem too ;) > > > > > > Andrea, could you point me at your ftp area? > > > > Sure, this is the very latest version I maintained: > > > > http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.26-rc7/mmu-notifier-v18/ > > Let me start with what XPMEM currently has. > > We adjusted xpmem so that the mmu_notifier_invalidate_page() callout > does not need to sleep. It takes the arguments passed in and adds them > to a queue for clearing the pages. We added a seperate kernel thread > which manages this clearing. > > The mmu_notifier_invalidate_range_end() likewise does not really need > to sleep either. > > That leaves the mmu_notifier_invalidate_range_start() callout. This does > not need to drop the mm_sem. It does need to be able to sleep waiting > for the invalidations to complete on the other process. That other > process may be on a different SSI connected to the same Numalink fabric. > > I think that with the SRCU patch, we have enough. Is that true or have > I missed something? I wasn't quite complete in my previous email. Your srcu patch plus Jack's patch to move the tlb_gather_mmu to after the mmu_notifier_invalidate_range_start(). Robin