Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758265Ab3CYJsc (ORCPT ); Mon, 25 Mar 2013 05:48:32 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:43558 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755262Ab3CYJsb (ORCPT ); Mon, 25 Mar 2013 05:48:31 -0400 Date: Mon, 25 Mar 2013 09:48:16 +0000 From: Russell King - ARM Linux To: Joonsoo Kim Cc: Will Deacon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Nicolas Pitre Subject: Re: [RFC PATCH 5/6] ARM, mm: change meaning of max_low_pfn to maximum pfn for nobootmem Message-ID: <20130325094816.GO4977@n2100.arm.linux.org.uk> References: <1364184674-13798-1-git-send-email-iamjoonsoo.kim@lge.com> <1364184674-13798-6-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1364184674-13798-6-git-send-email-iamjoonsoo.kim@lge.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1364 Lines: 27 On Mon, Mar 25, 2013 at 01:11:13PM +0900, Joonsoo Kim wrote: > nobootmem use max_low_pfn for computing boundary in free_all_bootmem() > So we need proper value to max_low_pfn. > > But, there is some difficulty related to max_low_pfn. max_low_pfn is used > for two meanings in various architectures. One is for number of pages > in lowmem and the other is for maximum lowmem pfn. Now, in ARM, it is used > as number of pages in lowmem. You can get more information in below link. > http://lwn.net/Articles/543408/ > http://lwn.net/Articles/543424/ > > As I investigated, architectures which use max_low_pfn as maximum pfn are > more than others, so to change meaning of max_low_pfn to maximum pfn > is preferable solution to me. This patch change max_low_pfn as maximum > lowmem pfn in ARM. In addition, min_low_pfn, max_pfn is assigned according > to this criteria. > > There is no real user for max_low_pfn except block/blk-setting.c and > blk-setting.c assume that max_low_pfn is maximum lowmem pfn, > so this patch may not harm anything. This will need some very rigorous testing before it can go into mainline. -- 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/