mm/page_alloc.c: remove pageblock_default_order()

commit 955c1cd7401565671b064e499115344ec8067dfd upstream.

This has always been broken: one version takes an unsigned int and the
other version takes no arguments.  This bug was hidden because one
version of set_pageblock_order() was a macro which doesn't evaluate its
argument.

Simplify it all and remove pageblock_default_order() altogether.

Reported-by: rajman mekaco <rajman.mekaco@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 508822e..3d888ef 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4254,25 +4254,24 @@ static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
 
 #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;
 }
@@ -4280,15 +4279,13 @@ static inline void __init set_pageblock_order(unsigned int order)
 
 /*
  * 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 */
 
@@ -4376,7 +4373,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                if (!size)
                        continue;
 
-               set_pageblock_order(pageblock_default_order());
+               set_pageblock_order();
                setup_usemap(pgdat, zone, zone_start_pfn, size);
                ret = init_currently_empty_zone(zone, zone_start_pfn,
                                                size, MEMMAP_EARLY);