mm: use roundown_pow_of_two() in zone_batchsize()

Use roundown_pow_of_two(N) in zone_batchsize() rather than (1 <<
(fls(N)-1)) as they are equivalent, and with the former it is easier to
see what is going on.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Lanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e2f26991fff1..8add7daf98b0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2706,7 +2706,7 @@ static int zone_batchsize(struct zone *zone)
          * of pages of one half of the possible page colors
          * and the other with pages of the other colors.
          */
-        batch = (1 << (fls(batch + batch/2)-1)) - 1;
+        batch = rounddown_pow_of_two(batch + batch/2) - 1;
 
         return batch;
 }