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| author |   Jens Axboe <axboe@kernel.dk> | 2018-11-16 08:37:34 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-11-19 08:34:49 -0700 |
| commit | 849a370016a5489c49253338507ee6cc4a08df4b (patch) | |
| tree | 3e8794bb4312b0fa73e3092849b8b6e163437a2d /fs/block_dev.c | |
| parent | nvme: default to 0 poll queues (diff) | |
| download | linux-dev-849a370016a5489c49253338507ee6cc4a08df4b.tar.xz linux-dev-849a370016a5489c49253338507ee6cc4a08df4b.zip | |
block: avoid ordered task state change for polled IO
For the core poll helper, the task state setting don't need to imply any
atomics, as it's the current task itself that is being modified and
we're not going to sleep.
For IRQ driven, the wakeup path have the necessary barriers to not need
us using the heavy handed version of the task state setting.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 4d79bc80fb41..64ba27b8b754 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -237,9 +237,11 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, qc = submit_bio(&bio); for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); + __set_current_state(TASK_UNINTERRUPTIBLE); + if (!READ_ONCE(bio.bi_private)) break; + if (!(iocb->ki_flags & IOCB_HIPRI) || !blk_poll(bdev_get_queue(bdev), qc)) io_schedule(); @@ -415,7 +417,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) return -EIOCBQUEUED; for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); + __set_current_state(TASK_UNINTERRUPTIBLE); + if (!READ_ONCE(dio->waiter)) break; |