From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id A8CF062000E for ; Thu, 11 Feb 2010 17:33:25 -0500 (EST) Date: Thu, 11 Feb 2010 16:32:51 -0600 (CST) From: Christoph Lameter Subject: Re: [patch] mm: suppress pfn range output for zones without pages In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Andrew Morton , Mel Gorman , linux-mm@kvack.org List-ID: On Thu, 11 Feb 2010, David Rientjes wrote: > So you want to parse this table of zone pfn ranges to determine, for > example, whether CONFIG_HIGHMEM was enabled for i386 kernels? That > doesn't tell you whether its CONFIG_HIGHMEM4G or CONFIG_HIGHMEM64G, so > it's a pretty bad way to interpret the kernel config and decide whether It tells me that there is highmem zone. > the pfn ranges are valid or not. The only other use case would be to find > if the values are sane when we don't have CONFIG_ZONE_DMA or > CONFIG_ZONE_DMA32, but those typically aren't even disabled: I just sent a > patch to the x86 maintainers to get that configuration to compile on -rc7. CONFIG_ZONE_DMA32 is disabled on 32 bit CONFIG_ZONE_DMA may be disabled on IA64 or other platforms that do have priviledged areas of memory. Strange embedded kernel configs may sometimes play tricks with ZONE_DMA. > In other words, I don't think we need to be emitting kernel diagnostic > messages for zones that are empty and unused just because they are enabled > in the kernel config; no developer is going to care about parsing the > usecase I showed in the changelog since ZONE_NORMAL is always defined. The kernel zone based arrays will still be dimensioned based on the configured zones even if you omit those from the display. This influences memory allocation. I do not feel strongly about this since I can always look at the .config files but you are removing information from the kernel log that I have been using in the past. -- 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