From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e4.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id j51NlX6p018057 for ; Wed, 1 Jun 2005 19:47:33 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.12.10/NCO/VER6.6) with ESMTP id j51NlXtR176204 for ; Wed, 1 Jun 2005 19:47:33 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11/8.13.3) with ESMTP id j51NlXIR031591 for ; Wed, 1 Jun 2005 19:47:33 -0400 Date: Wed, 1 Jun 2005 16:47:30 -0700 From: Mike Kravetz Subject: Re: Avoiding external fragmentation with a placement policy Version 12 Message-ID: <20050601234730.GF3998@w-mikek2.ibm.com> References: <20050531112048.D2511E57A@skynet.csn.ul.ie> <429E20B6.2000907@austin.ibm.com> <429E4023.2010308@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <429E4023.2010308@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: jschopp@austin.ibm.com, Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@osdl.org List-ID: On Thu, Jun 02, 2005 at 09:09:23AM +1000, Nick Piggin wrote: > > It adds a lot of complexity to the page allocator and while > it might be very good, the only improvement we've been shown > yet is allocating lots of MAX_ORDER allocations I think? (ie. > not very useful) > Allocating lots of MAX_ORDER blocks can be very useful for things like hot-pluggable memory. I know that this may not be of interest to most. However, I've been combining Mel's defragmenting patch with the memory hotplug patch set. As a result, I've been able to go from 5GB down to 544MB of memory on my ppc64 system via offline operations. Note that ppc64 only employs a single (DMA) zone. So, page 'grouping' based on use is coming mainly from Mel's patch. -- Mike -- 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: aart@kvack.org