mm: use SWP_SYNCHRONOUS_IO more intelligently

There is no point in trying to call bdev_read_page if SWP_SYNCHRONOUS_IO
is not set, as the device won't support it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2020-09-24 08:51:37 +02:00 committed by Jens Axboe
parent a8b456d01c
commit 5115db10a8

View File

@ -403,15 +403,17 @@ int swap_readpage(struct page *page, bool synchronous)
goto out;
}
ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
if (!ret) {
if (trylock_page(page)) {
swap_slot_free_notify(page);
unlock_page(page);
}
if (sis->flags & SWP_SYNCHRONOUS_IO) {
ret = bdev_read_page(sis->bdev, swap_page_sector(page), page);
if (!ret) {
if (trylock_page(page)) {
swap_slot_free_notify(page);
unlock_page(page);
}
count_vm_event(PSWPIN);
goto out;
count_vm_event(PSWPIN);
goto out;
}
}
ret = 0;