Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759046Ab2ECXhy (ORCPT ); Thu, 3 May 2012 19:37:54 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54967 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756946Ab2ECXhw (ORCPT ); Thu, 3 May 2012 19:37:52 -0400 Date: Thu, 3 May 2012 16:37:49 -0700 From: Andrew Morton To: rajman mekaco Cc: Mel Gorman , KAMEZAWA Hiroyuki , Tejun Heo , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-ia64@vger.kernel.org Subject: Re: [PATCH 1/1] page_alloc.c: remove argument to pageblock_default_order Message-Id: <20120503163749.d24bf07f.akpm@linux-foundation.org> In-Reply-To: <1336065312-2891-1-git-send-email-rajman.mekaco@gmail.com> References: <1336065312-2891-1-git-send-email-rajman.mekaco@gmail.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3959 Lines: 126 On Thu, 3 May 2012 22:45:12 +0530 rajman mekaco wrote: > When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not defined, then > pageblock_default_order has an argument to it. > > However, free_area_init_core will call it without any argument > anyway. > > Remove the argument to pageblock_default_order when > CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not defined. > > Signed-off-by: rajman mekaco > --- > mm/page_alloc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index a712fb9..4b95412 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4274,7 +4274,7 @@ static inline void __init set_pageblock_order(unsigned int order) > * at compile-time. See include/linux/pageblock-flags.h for the values of > * pageblock_order based on the kernel config > */ > -static inline int pageblock_default_order(unsigned int order) > +static inline int pageblock_default_order(void) > { > return MAX_ORDER-1; > } Interesting. It has been that way since at least 3.1. It didn't break the build because pageblock_default_order() is only ever invoked by set_pageblock_order(), with: set_pageblock_order(pageblock_default_order()); and set_pageblock_order() is a macro: #define set_pageblock_order(x) do {} while (0) There's yet another reason not to use macros, dammit - they hide bugs. Mel, can you have a think about this please? Can we just kill off pageblock_default_order() and fold its guts into set_pageblock_order(void)? Only ia64 and powerpc can define CONFIG_HUGETLB_PAGE_SIZE_VARIABLE. --- a/mm/page_alloc.c~a +++ a/mm/page_alloc.c @@ -4300,25 +4300,24 @@ static inline void setup_usemap(struct p #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE -/* Return a sensible default order for the pageblock size. */ -static inline int pageblock_default_order(void) -{ - if (HPAGE_SHIFT > PAGE_SHIFT) - return HUGETLB_PAGE_ORDER; - - return MAX_ORDER-1; -} - /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ -static inline void __init set_pageblock_order(unsigned int order) +static inline void __init set_pageblock_order(void) { + unsigned int order; + /* Check that pageblock_nr_pages has not already been setup */ if (pageblock_order) return; + if (HPAGE_SHIFT > PAGE_SHIFT) + order = HUGETLB_PAGE_ORDER; + else + order = MAX_ORDER - 1; + /* * Assume the largest contiguous order of interest is a huge page. - * This value may be variable depending on boot parameters on IA64 + * This value may be variable depending on boot parameters on IA64 and + * powerpc. */ pageblock_order = order; } @@ -4326,15 +4325,13 @@ static inline void __init set_pageblock_ /* * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() - * and pageblock_default_order() are unused as pageblock_order is set - * at compile-time. See include/linux/pageblock-flags.h for the values of - * pageblock_order based on the kernel config + * is unused as pageblock_order is set at compile-time. See + * include/linux/pageblock-flags.h for the values of pageblock_order based on + * the kernel config */ -static inline int pageblock_default_order(unsigned int order) +static inline void set_pageblock_order(void) { - return MAX_ORDER-1; } -#define set_pageblock_order(x) do {} while (0) #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ @@ -4422,7 +4419,7 @@ static void __paginginit free_area_init_ if (!size) continue; - set_pageblock_order(pageblock_default_order()); + set_pageblock_order(); setup_usemap(pgdat, zone, size); ret = init_currently_empty_zone(zone, zone_start_pfn, size, MEMMAP_EARLY); _ -- 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/