This patch replaces a loop with a "tzcnt" instruction.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -1020,11 +1020,7 @@ grow_buffers(struct block_device *bdev,
pgoff_t index;
int sizebits;
- sizebits = -1;
- do {
- sizebits++;
- } while ((size << sizebits) < PAGE_SIZE);
-
+ sizebits = PAGE_SHIFT - __ffs(size);
index = block >> sizebits;
/*
