On Mon, 2020-08-24 at 12:18 -0700, Andrew Morton wrote: > On Mon, 24 Aug 2020 07:53:54 -0400 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: > > > Add else to split mutually exclusive case and avoid some unnecessary check. > > > > --- a/mm/mempool.c > > +++ b/mm/mempool.c > > @@ -60,9 +60,8 @@ static void check_element(mempool_t *pool, void *element) > > /* Mempools backed by slab allocator */ > > if (pool->free == mempool_free_slab || pool->free == mempool_kfree) > > __check_element(pool, element, ksize(element)); > > - > > /* Mempools backed by page allocator */ > > - if (pool->free == mempool_free_pages) { > > + else if (pool->free == mempool_free_pages) { > > int order = (int)(long)pool->pool_data; > > void *addr = kmap_atomic((struct page *)element); > > > > It doesn't seem to change code generation (compiler is smart), but I > think it helps readability. style: braces should be added to the first test. Perhaps better as: --- mm/mempool.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/mempool.c b/mm/mempool.c index 79bff63ecf27..d0206eab86a4 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -57,12 +57,12 @@ static void __check_element(mempool_t *pool, void *element, size_t size) static void check_element(mempool_t *pool, void *element) { - /* Mempools backed by slab allocator */ - if (pool->free == mempool_free_slab || pool->free == mempool_kfree) + if (pool->free == mempool_free_slab || + pool->free == mempool_kfree) { + /* Mempools backed by slab allocator */ __check_element(pool, element, ksize(element)); - - /* Mempools backed by page allocator */ - if (pool->free == mempool_free_pages) { + } else if (pool->free == mempool_free_pages) { + /* Mempools backed by page allocator */ int order = (int)(long)pool->pool_data; void *addr = kmap_atomic((struct page *)element);