From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 72D7F6B0047 for ; Thu, 11 Feb 2010 17:28:16 -0500 (EST) Date: Thu, 11 Feb 2010 14:27:34 -0800 From: Andrew Morton Subject: Re: [patch] mm: suppress pfn range output for zones without pages Message-Id: <20100211142734.24df7447.akpm@linux-foundation.org> In-Reply-To: References: <20100211122507.GA32292@csn.ul.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Mel Gorman , linux-mm@kvack.org, Christoph Lameter List-ID: On Thu, 11 Feb 2010 13:26:37 -0800 (PST) David Rientjes wrote: > On Thu, 11 Feb 2010, Mel Gorman wrote: > > > > free_area_init_nodes() emits pfn ranges for all zones on the system. > > > There may be no pages on a higher zone, however, due to memory > > > limitations or the use of the mem= kernel parameter. For example: > > > > > > Zone PFN ranges: > > > DMA 0x00000001 -> 0x00001000 > > > DMA32 0x00001000 -> 0x00100000 > > > Normal 0x00100000 -> 0x00100000 > > > > > > The implementation copies the previous zone's highest pfn, if any, as the > > > next zone's lowest pfn. If its highest pfn is then greater than the > > > amount of addressable memory, the upper memory limit is used instead. > > > Thus, both the lowest and highest possible pfn for higher zones without > > > memory may be the same. > > > > > > The output is now suppressed for zones that do not have a valid pfn > > > range. > > > > > > > I see no problem with the patch. Was it a major problem or just > > confusing? > > > > It was just confusing, I don't think anybody would be parsing the kernel > log for this specifically to determine whether ZONE_NORMAL exists :) > > > > Cc: Mel Gorman > > > Signed-off-by: David Rientjes > > > > Reviewed-by: Mel Gorman > > > > Thanks! I ducked this patch because Christoph's complaint sounded reasonable - by suppressing this output we're removing information. -- 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