[PATCH 1/3] Use roundown_pow_of_two() in zone_batchsize()

From: David Howells
Date: Tue May 05 2009 - 17:28:35 EST


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@xxxxxxxxxx>
Tested-by: Lanttor Guo <lanttor.guo@xxxxxxxxxxxxx>
---

mm/page_alloc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e2f2699..8add7da 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;
}

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