From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH] Apply memory policies to top two highest zones when highest zone is ZONE_MOVABLE Date: Sat, 4 Aug 2007 00:02:17 +0200 References: <20070802172118.GD23133@skynet.ie> In-Reply-To: <20070802172118.GD23133@skynet.ie> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200708040002.18167.ak@suse.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: akpm@linux-foundation.org, Lee.Schermerhorn@hp.com, clameter@sgi.com, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Thursday 02 August 2007 19:21:18 Mel Gorman wrote: > The NUMA layer only supports NUMA policies for the highest zone. When > ZONE_MOVABLE is configured with kernelcore=, the the highest zone becomes > ZONE_MOVABLE. The result is that policies are only applied to allocations > like anonymous pages and page cache allocated from ZONE_MOVABLE when the > zone is used. > > This patch applies policies to the two highest zones when the highest zone > is ZONE_MOVABLE. As ZONE_MOVABLE consists of pages from the highest "real" > zone, it's always functionally equivalent. > > The patch has been tested on a variety of machines both NUMA and non-NUMA > covering x86, x86_64 and ppc64. No abnormal results were seen in kernbench, > tbench, dbench or hackbench. It passes regression tests from the numactl > package with and without kernelcore= once numactl tests are patched to > wait for vmstat counters to update. I must honestly say I really hate the patch. It's a horrible hack and makes fast paths slower. When I designed mempolicies I especially tried to avoid things like that, please don't add them through the backdoor now. -Andi -- 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: email@kvack.org