Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760134AbZJHXg0 (ORCPT ); Thu, 8 Oct 2009 19:36:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760124AbZJHXgZ (ORCPT ); Thu, 8 Oct 2009 19:36:25 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:33323 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932092AbZJHXgX (ORCPT ); Thu, 8 Oct 2009 19:36:23 -0400 Date: Thu, 8 Oct 2009 16:34:49 -0700 From: Andrew Morton To: Robert Jennings Cc: Mel Gorman , Ingo Molnar , Badari Pulavarty , Brian King , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org, KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/2][v2] mm: add notifier in pageblock isolation for balloon drivers Message-Id: <20091008163449.00dce972.akpm@linux-foundation.org> In-Reply-To: <20091002184458.GC4908@austin.ibm.com> References: <20091002184458.GC4908@austin.ibm.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 36 On Fri, 2 Oct 2009 13:44:58 -0500 Robert Jennings wrote: > Memory balloon drivers can allocate a large amount of memory which > is not movable but could be freed to accomodate memory hotplug remove. > > Prior to calling the memory hotplug notifier chain the memory in the > pageblock is isolated. If the migrate type is not MIGRATE_MOVABLE the > isolation will not proceed, causing the memory removal for that page > range to fail. > > Rather than failing pageblock isolation if the the migrateteype is not > MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock > are owned by a registered balloon driver (or other entity) using a > notifier chain. If all of the non-movable pages are owned by a balloon, > they can be freed later through the memory notifier chain and the range > can still be isolated in set_migratetype_isolate(). The patch looks sane enough to me. I expect that if the powerpc and s390 guys want to work on CMM over the next couple of months, they'd like this patch merged into 2.6.32. It's a bit larger and more involved than one would like, but I guess we can do that if suitable people (Mel? Kamezawa?) have had a close look and are OK with it. What do people think? Has it been carefully compile- and run-time tested with CONFIG_MEMORY_HOTPLUG_SPARSE=n? -- 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/