From 98cc093cba1e925eb34963dedb5f1684f1bdb2f4 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 6 Sep 2017 16:22:27 -0700 Subject: block, THP: make block_device_operations.rw_page support THP The .rw_page in struct block_device_operations is used by the swap subsystem to read/write the page contents from/into the corresponding swap slot in the swap device. To support the THP (Transparent Huge Page) swap optimization, the .rw_page is enhanced to support to read/write THP if possible. Link: http://lkml.kernel.org/r/20170724051840.2309-6-ying.huang@intel.com Signed-off-by: "Huang, Ying" Reviewed-by: Ross Zwisler [for brd.c, zram_drv.c, pmem.c] Cc: Johannes Weiner Cc: Minchan Kim Cc: Dan Williams Cc: Vishal L Verma Cc: Jens Axboe Cc: "Kirill A . Shutemov" Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Michal Hocko Cc: Rik van Riel Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/brd.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/block/brd.c') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 104b71c0490d..5d9ed0616413 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -326,7 +326,11 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, struct page *page, bool is_write) { struct brd_device *brd = bdev->bd_disk->private_data; - int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector); + int err; + + if (PageTransHuge(page)) + return -ENOTSUPP; + err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector); page_endio(page, is_write, err); return err; } -- cgit v1.2.3