From aa563d7bca6e882ec2bdae24603c8f016401a144 Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 20 Oct 2018 00:57:56 +0100 Subject: iov_iter: Separate type from direction and use accessor functions In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells --- mm/page_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/page_io.c') diff --git a/mm/page_io.c b/mm/page_io.c index aafd19ec1db4..86de453a60cf 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -294,7 +294,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, }; struct iov_iter from; - iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE); + iov_iter_bvec(&from, WRITE, &bv, 1, PAGE_SIZE); init_sync_kiocb(&kiocb, swap_file); kiocb.ki_pos = page_file_offset(page); -- cgit