Two cleanups in this patch:
* since pageblock_nr_pages == (1 << pageblock_order), the roundup()
and right shift pageblock_order could be replaced with
DIV_ROUND_UP()
* use BITS_TO_LONGS() to get number of bytes for bitmap
This patch also fix one typo in comment.
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
mm/page_alloc.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d295c9bc01a8..d7073cedd087 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6352,7 +6352,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
/*
* Calculate the size of the zone->blockflags rounded to an unsigned long
* Start by making sure zonesize is a multiple of pageblock_order by rounding
- * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
+ * up. Then use 1 NR_PAGEBLOCK_BITS width of bits per pageblock, finally
* round what is now in bits to nearest long in bits, then return it in
* bytes.
*/
@@ -6361,12 +6361,9 @@ static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned l
unsigned long usemapsize;
zonesize += zone_start_pfn & (pageblock_nr_pages-1);
- usemapsize = roundup(zonesize, pageblock_nr_pages);
- usemapsize = usemapsize >> pageblock_order;
+ usemapsize = DIV_ROUND_UP(zonesize, pageblock_nr_pages);
usemapsize *= NR_PAGEBLOCK_BITS;
- usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
-
- return usemapsize / 8;
+ return BITS_TO_LONGS(usemapsize) * sizeof(unsigned long);
}
static void __ref setup_usemap(struct pglist_data *pgdat,
--
2.15.1
