2 files changed, 26 insertions, 2 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 18f397ca05ef..232c298c933f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -187,6 +187,11 @@ config FORCE_MAX_ZONEORDER
         default "9" if PPC_64K_PAGES
         default "13"
 
+config HUGETLB_PAGE_SIZE_VARIABLE
+        bool
+        depends on HUGETLB_PAGE
+        default y
+
 config MATH_EMULATION
         bool "Math emulation"
         depends on 4xx || 8xx || E200 || PPC_MPC832x || E500
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4ffed1cd158b..b5a58d476c1a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3265,6 +3265,16 @@ static void inline setup_usemap(struct pglist_data *pgdat,
 #endif /* CONFIG_SPARSEMEM */
 
 #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)
 {
@@ -3280,7 +3290,16 @@ static inline void __init set_pageblock_order(unsigned int order)
 }
 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
 
-/* Defined this way to avoid accidently referencing HUGETLB_PAGE_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
+ */
+static inline int pageblock_default_order(unsigned int order)
+{
+        return MAX_ORDER-1;
+}
 #define set_pageblock_order(x)  do {} while (0)
 
 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
@@ -3365,7 +3384,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat,
                 if (!size)
                         continue;
 
-                set_pageblock_order(HUGETLB_PAGE_ORDER);
+                set_pageblock_order(pageblock_default_order());
                 setup_usemap(pgdat, zone, size);
                 ret = init_currently_empty_zone(zone, zone_start_pfn,
                                                 size, MEMMAP_EARLY);