Messages in this thread Patch in this message | | | From | David Laight <> | Subject | [PATCH 10/13] lib/generic-radix-tree: Simplify offset calculation: | Date | Tue, 25 Aug 2020 14:52:47 +0000 |
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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@aculab.com> --- 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 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
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