From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422809AbXCBDnG (ORCPT ); Thu, 1 Mar 2007 22:43:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422817AbXCBDnG (ORCPT ); Thu, 1 Mar 2007 22:43:06 -0500 Received: from fgwnews.fujitsu.co.jp ([164.71.1.134]:60472 "EHLO fgwnews.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422809AbXCBDnF (ORCPT ); Thu, 1 Mar 2007 22:43:05 -0500 X-Greylist: delayed 4031 seconds by postgrey-1.27 at vger.kernel.org; Thu, 01 Mar 2007 22:43:04 EST Date: Fri, 2 Mar 2007 11:34:12 +0900 From: KAMEZAWA Hiroyuki To: Andrew Morton Cc: mel@skynet.ie, npiggin@suse.de, clameter@engr.sgi.com, mingo@elte.hu, jschopp@austin.ibm.com, arjan@infradead.org, torvalds@linux-foundation.org, mbligh@mbligh.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: The performance and behaviour of the anti-fragmentation related patches Message-Id: <20070302113412.eeacb60d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20070301160915.6da876c5.akpm@linux-foundation.org> References: <20070301101249.GA29351@skynet.ie> <20070301160915.6da876c5.akpm@linux-foundation.org> Organization: Fujitsu X-Mailer: Sylpheed version 2.2.0 (GTK+ 2.6.10; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 1 Mar 2007 16:09:15 -0800 Andrew Morton wrote: > On Thu, 1 Mar 2007 10:12:50 +0000 > mel@skynet.ie (Mel Gorman) wrote: > > > Any opinion on merging these patches into -mm > > for wider testing? > > I'm a little reluctant to make changes to -mm's core mm unless those > changes are reasonably certain to be on track for mainline, so let's talk > about that. > > What worries me is memory hot-unplug and per-container RSS limits. We > don't know how we're going to do either of these yet, and it could well be > that the anti-frag work significantly complexicates whatever we end up > doing there. > > For prioritisation purposes I'd judge that memory hot-unplug is of similar > value to the antifrag work (because memory hot-unplug permits DIMM > poweroff). About memory-hot-unplug, I'm now writing a new patch-set for memory-unplug for showing my overview and roadmap. I'm now debugging it. I think I will be able to post them as RFC in a week. At least, ZONE_MOVABLE(or something partitioning memory) is necessary for memory-hot-unplug like DIMM-poweroff. (I'm now using my own ZONE_MOVABLE patch, but It is O.K. to migrate to Mel's one if it's ready to be merged.) > Our basic unit of memory management is the zone. Right now, a zone maps > onto some hardware-imposed thing. But the zone-based MM works *well*. I > suspect that a good way to solve both per-container RSS and mem hotunplug > is to split the zone concept away from its hardware limitations: create a > "software zone" and a "hardware zone". All the existing page allocator and > reclaim code remains basically unchanged, and it operates on "software > zones". Each software zones always lies within a single hardware zone. > The software zones are resizeable. For per-container RSS we give each > container one (or perhaps multiple) resizeable software zones. > > For memory hotunplug, some of the hardware zone's software zones are marked > reclaimable and some are not; DIMMs which are wholly within reclaimable > zones can be depopulated and powered off or removed. > Hmm...software-zone seems attractive. I remember someone posted pesuedo-zone(pzone) patch in past. -Kame