From d1e36282b0bbd5de6a9c4d5275e94ef3b3438f48 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 29 Aug 2018 10:36:56 -0600 Subject: block: add REQ_HIPRI and inherit it from IOCB_HIPRI We use IOCB_HIPRI to poll for IO in the caller instead of scheduling. This information is not available for (or after) IO submission. The driver may make different queue choices based on the type of IO, so make the fact that we will poll for this IO known to the lower layers as well. Reviewed-by: Hannes Reinecke Reviewed-by: Keith Busch Reviewed-by: Sagi Grimberg Signed-off-by: Jens Axboe --- fs/direct-io.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/direct-io.c') diff --git a/fs/direct-io.c b/fs/direct-io.c index 722d17c88edb90..ea07d5a34317dc 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1265,6 +1265,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, } else { dio->op = REQ_OP_READ; } + if (iocb->ki_flags & IOCB_HIPRI) + dio->op_flags |= REQ_HIPRI; /* * For AIO O_(D)SYNC writes we need to defer completions to a workqueue -- cgit 1.2.3-korg From 0a1b8b87d064a47fad9ec475316002da28559207 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 26 Nov 2018 08:24:43 -0700 Subject: block: make blk_poll() take a parameter on whether to spin or not blk_poll() has always kept spinning until it found an IO. This is fine for SYNC polling, since we need to find one request we have pending, but in preparation for ASYNC polling it can be beneficial to just check if we have any entries available or not. Existing callers are converted to pass in 'spin == true', to retain the old behavior. Signed-off-by: Jens Axboe --- block/blk-core.c | 9 ++++++--- block/blk-mq.c | 6 +++--- drivers/nvme/host/multipath.c | 4 ++-- fs/block_dev.c | 4 ++-- fs/direct-io.c | 2 +- fs/iomap.c | 2 +- include/linux/blkdev.h | 4 ++-- mm/page_io.c | 2 +- 8 files changed, 18 insertions(+), 15 deletions(-) (limited to 'fs/direct-io.c') diff --git a/block/blk-core.c b/block/blk-core.c index 03c4202b69bf00..9af56dbb84f111 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1277,19 +1277,22 @@ EXPORT_SYMBOL(submit_bio); * blk_poll - poll for IO completions * @q: the queue * @cookie: cookie passed back at IO submission time + * @spin: whether to spin for completions * * Description: * Poll for completions on the passed in queue. Returns number of - * completed entries found. + * completed entries found. If @spin is true, then blk_poll will continue + * looping until at least one completion is found, unless the task is + * otherwise marked running (or we need to reschedule). */ -int blk_poll(struct request_queue *q, blk_qc_t cookie) +int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) { if (!q->poll_fn || !blk_qc_t_valid(cookie)) return 0; if (current->plug) blk_flush_plug_list(current->plug, false); - return q->poll_fn(q, cookie); + return q->poll_fn(q, cookie, spin); } EXPORT_SYMBOL_GPL(blk_poll); diff --git a/block/blk-mq.c b/block/blk-mq.c index b66cca3ce1e51e..c2751f0a3ccc0f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -38,7 +38,7 @@ #include "blk-mq-sched.h" #include "blk-rq-qos.h" -static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie); +static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, bool spin); static void blk_mq_poll_stats_start(struct request_queue *q); static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); @@ -3352,7 +3352,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q, return blk_mq_poll_hybrid_sleep(q, hctx, rq); } -static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie) +static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, bool spin) { struct blk_mq_hw_ctx *hctx; long state; @@ -3392,7 +3392,7 @@ static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie) if (current->state == TASK_RUNNING) return 1; - if (ret < 0) + if (ret < 0 || !spin) break; cpu_relax(); } diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index f9eeb3b5863290..ffebdd0ae34bef 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -220,7 +220,7 @@ static blk_qc_t nvme_ns_head_make_request(struct request_queue *q, return ret; } -static int nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc) +static int nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc, bool spin) { struct nvme_ns_head *head = q->queuedata; struct nvme_ns *ns; @@ -230,7 +230,7 @@ static int nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc) srcu_idx = srcu_read_lock(&head->srcu); ns = srcu_dereference(head->current_path[numa_node_id()], &head->srcu); if (likely(ns && nvme_path_is_optimized(ns))) - found = ns->queue->poll_fn(q, qc); + found = ns->queue->poll_fn(q, qc, spin); srcu_read_unlock(&head->srcu, srcu_idx); return found; } diff --git a/fs/block_dev.c b/fs/block_dev.c index 64ba27b8b7549e..d233a59ea364e6 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -243,7 +243,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, break; if (!(iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(bdev_get_queue(bdev), qc)) + !blk_poll(bdev_get_queue(bdev), qc, true)) io_schedule(); } __set_current_state(TASK_RUNNING); @@ -423,7 +423,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) break; if (!(iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(bdev_get_queue(bdev), qc)) + !blk_poll(bdev_get_queue(bdev), qc, true)) io_schedule(); } __set_current_state(TASK_RUNNING); diff --git a/fs/direct-io.c b/fs/direct-io.c index ea07d5a34317dc..a5a4e5a1423eee 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -518,7 +518,7 @@ static struct bio *dio_await_one(struct dio *dio) dio->waiter = current; spin_unlock_irqrestore(&dio->bio_lock, flags); if (!(dio->iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(dio->bio_disk->queue, dio->bio_cookie)) + !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true)) io_schedule(); /* wake up sets us TASK_RUNNING */ spin_lock_irqsave(&dio->bio_lock, flags); diff --git a/fs/iomap.c b/fs/iomap.c index c5df035ace6f30..74c1f37f0fd6b5 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1896,7 +1896,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (!(iocb->ki_flags & IOCB_HIPRI) || !dio->submit.last_queue || !blk_poll(dio->submit.last_queue, - dio->submit.cookie)) + dio->submit.cookie, true)) io_schedule(); } __set_current_state(TASK_RUNNING); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f3015e9b5ae37b..e3c0a8ec16a79e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -283,7 +283,7 @@ static inline unsigned short req_get_ioprio(struct request *req) struct blk_queue_ctx; typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio); -typedef int (poll_q_fn) (struct request_queue *q, blk_qc_t); +typedef int (poll_q_fn) (struct request_queue *q, blk_qc_t, bool spin); struct bio_vec; typedef int (dma_drain_needed_fn)(struct request *); @@ -867,7 +867,7 @@ extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, int blk_status_to_errno(blk_status_t status); blk_status_t errno_to_blk_status(int errno); -int blk_poll(struct request_queue *q, blk_qc_t cookie); +int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin); static inline struct request_queue *bdev_get_queue(struct block_device *bdev) { diff --git a/mm/page_io.c b/mm/page_io.c index a7271fa481f6e3..5bdfd21c1bd9f0 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -410,7 +410,7 @@ int swap_readpage(struct page *page, bool synchronous) if (!READ_ONCE(bio->bi_private)) break; - if (!blk_poll(disk->queue, qc)) + if (!blk_poll(disk->queue, qc, true)) break; } __set_current_state(TASK_RUNNING); -- cgit 1.2.3-korg