[PATCH 10/13] lib/generic-radix-tree: Simplify offset calculation:

[David Laight]

Since these are equivalent:
    (idx / objs_per_page) * PAGE_SIZE + (idx % objs_per_page) * obj_size;
    idx * obj_size + (idx / objs_per_page) * (PAGE_SIZE % obj_size);
Use the latter since it is slightly faster.
It also deosn't need an extra check for obj_size being a power of 2.

Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
---
 include/linux/generic-radix-tree.h | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/include/linux/generic-radix-tree.h b/include/linux/generic-radix-tree.h
index 53149bc1b92a..5fe1c4c5588d 100644
--- a/include/linux/generic-radix-tree.h
+++ b/include/linux/generic-radix-tree.h
@@ -100,14 +100,9 @@ void __genradix_free(struct __genradix *);
 
 static inline size_t __idx_to_offset(size_t idx, size_t obj_size)
 {
-	if (!is_power_of_2(obj_size)) {
-		size_t objs_per_page = PAGE_SIZE / obj_size;
+	size_t objs_per_page = PAGE_SIZE / obj_size;
 
-		return (idx / objs_per_page) * PAGE_SIZE +
-			(idx % objs_per_page) * obj_size;
-	} else {
-		return idx * obj_size;
-	}
+	return idx * obj_size + (idx / objs_per_page) * (PAGE_SIZE % obj_size);
 }
 
 #define __genradix_cast(_radix)		(typeof((_radix)->type[0]) *)
-- 
2.25.1

-
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