mm/mm_init.c: use round_up() to calculate usermap size

Since pageblock_nr_pages and BITS_PER_LONG are power of 2, we could use
round_up() to calculate it.

Also we have renamed blockflags to pageblock_flags, adjust the comment
accordingly.

Link: https://lkml.kernel.org/r/20250212013818.873-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: Shivank Garg <shivankg@amd.com>
Reviewed-by: Shivank Garg <shivankg@amd.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 6078b3651f2e1f6e6210775375eda870a99eb6be..c767946e8f5fd461eaac4ef5a32de11931c95beb 100644 (file)
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1431,7 +1431,7 @@ void __meminit init_currently_empty_zone(struct zone *zone,
 
 #ifndef CONFIG_SPARSEMEM
 /*
- * Calculate the size of the zone->blockflags rounded to an unsigned long
+ * Calculate the size of the zone->pageblock_flags 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
  * round what is now in bits to nearest long in bits, then return it in
@@ -1442,10 +1442,10 @@ 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 = round_up(zonesize, pageblock_nr_pages);
        usemapsize = usemapsize >> pageblock_order;
        usemapsize *= NR_PAGEBLOCK_BITS;
-       usemapsize = roundup(usemapsize, BITS_PER_LONG);
+       usemapsize = round_up(usemapsize, BITS_PER_LONG);
 
        return usemapsize / BITS_PER_BYTE;
 }