Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967955AbWLEBNH (ORCPT ); Mon, 4 Dec 2006 20:13:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S967957AbWLEBNH (ORCPT ); Mon, 4 Dec 2006 20:13:07 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:60213 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967955AbWLEBNE (ORCPT ); Mon, 4 Dec 2006 20:13:04 -0500 Date: Tue, 5 Dec 2006 10:16:29 +0900 From: KAMEZAWA Hiroyuki To: Mel Gorman Cc: akpm@osdl.org, clameter@sgi.com, apw@shadowen.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Add __GFP_MOVABLE for callers to flag allocations that may be migrated Message-Id: <20061205101629.5cb78828.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20061130170746.GA11363@skynet.ie> <20061130173129.4ebccaa2.akpm@osdl.org> <20061201110103.08d0cf3d.akpm@osdl.org> <20061204140747.GA21662@skynet.ie> <20061204113051.4e90b249.akpm@osdl.org> <20061204143435.6ab587db.akpm@osdl.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 Content-Length: 2271 Lines: 51 Hi, your plan looks good to me. some comments. On Mon, 4 Dec 2006 23:45:32 +0000 (GMT) Mel Gorman wrote: > 1. Use lumpy-reclaim to intelligently reclaim contigous pages. The same > logic can be used to reclaim within a PFN range > 2. Merge anti-frag to help high-order allocations, hugetlbpage > allocations and freeing up SPARSEMEM sections of memory For freeing up SPARSEMEM sections of memory ? It looks that you assumes MAX_ORDER_NR_PAGES equals to PAGES_PER_SECTION. plz don't assume that when you talk about generic arch code. > 3. Anti-frag includes support for page flags that affected a MAX_ORDER block > of pages. These flags can be used to mark a section of memory that should > not be allocated from. This is of interest to both hugetlb page allocatoin > and memory hot-remove. Use the flags to mark a MAX_ORDER_NR_PAGES that > is currently being freed up and shouldn't be allocated. > 4. Use anti-frag fallback logic to bias unmovable allocations to the lower > PFNs. I think this can be one of the most diffcult things ;) > 5. Add arch support where possible for offlining sections of memory that > can be powered down. I had a patch for ACPI-memory-hot-unplug, which ties memory sections to memory chunk on ACPI. > 6. Add arch support where possible to power down a DIMM when the memory > sections that make it up have been offlined. This is an extenstion of > step 5 only. > 7. Add a zone that only allows __GFP_MOVABLE allocations so that > sections can 100% be reclaimed and powered-down > 8. Allow nodes to only have a zone for __GFP_MOVABLE allocations so that > whole nodes can be offlined. > I (numa-node-hotplug) needs 7 and 8 basically. And Other people may not. IMHO: For DIMM unplug, I suspect that we'll finally divide memory to core-memory and hot-pluggable by pgdat even on SMP. If we use pgdat for that purpose, almost all necessary infrastructure(statistics ,etc..) is ready. But if we find better way, it's good. -Kame - 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/