On Mon, Oct 14, 2019 at 10:43:13PM +0800, yangerkun wrote: > Just set REQ_HIPRI for the last bio in iomap_dio_bio_actor. Because > multi bio created by this function can goto different cpu since this > process can be preempted by other process. And in iomap_dio_rw we will > just poll for the last bio. Fix it by only set polled for the last bio. I agree that there is a problem with the separate poll queue now. But doing partially polled I/O also doesn't seem very useful. Until we can find a way to poll for multiple bios from one kiocb I think we need to limit polling to iocbs with just a single bio. Can you look into that? __blkdev_direct_IO do_blockdev_direct_IO probably have the same issues. The former should be just as simple to fix, and for the latter it might make sense to drop polling support entirely.
