From ef99b2d37666b7a600baab9e1c4944436652b0a2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 12 Oct 2021 13:12:19 +0200 Subject: [PATCH] block: replace the spin argument to blk_iopoll with a flags argument Switch the boolean spin argument to blk_poll to passing a set of flags instead. This will allow to control polling behavior in a more fine grained way. Signed-off-by: Christoph Hellwig Tested-by: Mark Wunderlich Link: https://lore.kernel.org/r/20211012111226.760968-10-hch@lst.de [axboe: adapt to changed io_uring iopoll] Signed-off-by: Jens Axboe --- block/blk-exec.c | 2 +- block/blk-mq.c | 17 +++++++---------- block/fops.c | 8 ++++---- fs/io_uring.c | 9 +++++---- fs/iomap/direct-io.c | 6 +++--- include/linux/blkdev.h | 4 +++- include/linux/fs.h | 2 +- include/linux/iomap.h | 2 +- mm/page_io.c | 2 +- 9 files changed, 26 insertions(+), 26 deletions(-) diff --git a/block/blk-exec.c b/block/blk-exec.c index d6cd501c0d34..1fa7f25e5726 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -71,7 +71,7 @@ static bool blk_rq_is_poll(struct request *rq) static void blk_rq_poll_completion(struct request *rq, struct completion *wait) { do { - blk_poll(rq->q, request_to_qc_t(rq->mq_hctx, rq), true); + blk_poll(rq->q, request_to_qc_t(rq->mq_hctx, rq), 0); cond_resched(); } while (!completion_done(wait)); } diff --git a/block/blk-mq.c b/block/blk-mq.c index 7d0d947921a6..6609e10657a8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4052,7 +4052,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q, blk_qc_t qc) } static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, - bool spin) + unsigned int flags) { struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, cookie); long state = get_current_state(); @@ -4075,7 +4075,7 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, if (task_is_running(current)) return 1; - if (ret < 0 || !spin) + if (ret < 0 || (flags & BLK_POLL_ONESHOT)) break; cpu_relax(); } while (!need_resched()); @@ -4088,15 +4088,13 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, * blk_poll - poll for IO completions * @q: the queue * @cookie: cookie passed back at IO submission time - * @spin: whether to spin for completions + * @flags: BLK_POLL_* flags that control the behavior * * Description: * Poll for completions on the passed in queue. Returns number of - * 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). + * completed entries found. */ -int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) +int blk_poll(struct request_queue *q, blk_qc_t cookie, unsigned int flags) { if (cookie == BLK_QC_T_NONE || !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) @@ -4105,12 +4103,11 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) if (current->plug) blk_flush_plug_list(current->plug, false); - /* If specified not to spin, we also should not sleep. */ - if (spin && q->poll_nsec != BLK_MQ_POLL_CLASSIC) { + if (q->poll_nsec != BLK_MQ_POLL_CLASSIC) { if (blk_mq_poll_hybrid(q, cookie)) return 1; } - return blk_mq_poll_classic(q, cookie, spin); + return blk_mq_poll_classic(q, cookie, flags); } EXPORT_SYMBOL_GPL(blk_poll); diff --git a/block/fops.c b/block/fops.c index 15324f2e5a91..db8f2fe68dd2 100644 --- a/block/fops.c +++ b/block/fops.c @@ -108,7 +108,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, if (!READ_ONCE(bio.bi_private)) break; if (!(iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(bdev_get_queue(bdev), qc, true)) + !blk_poll(bdev_get_queue(bdev), qc, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -141,12 +141,12 @@ struct blkdev_dio { static struct bio_set blkdev_dio_pool; -static int blkdev_iopoll(struct kiocb *kiocb, bool wait) +static int blkdev_iopoll(struct kiocb *kiocb, unsigned int flags) { struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host); struct request_queue *q = bdev_get_queue(bdev); - return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait); + return blk_poll(q, READ_ONCE(kiocb->ki_cookie), flags); } static void blkdev_bio_end_io(struct bio *bio) @@ -297,7 +297,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, if (!READ_ONCE(dio->waiter)) break; - if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, true)) + if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); diff --git a/fs/io_uring.c b/fs/io_uring.c index d2e86788c872..541fec2bd49a 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2457,14 +2457,15 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, long min) { struct io_kiocb *req, *tmp; + unsigned int poll_flags = 0; LIST_HEAD(done); - bool spin; /* * Only spin for completions if we don't have multiple devices hanging * off our complete list, and we're under the requested amount. */ - spin = !ctx->poll_multi_queue && *nr_events < min; + if (ctx->poll_multi_queue || *nr_events >= min) + poll_flags |= BLK_POLL_ONESHOT; list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { struct kiocb *kiocb = &req->rw.kiocb; @@ -2482,11 +2483,11 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, if (!list_empty(&done)) break; - ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); + ret = kiocb->ki_filp->f_op->iopoll(kiocb, poll_flags); if (unlikely(ret < 0)) return ret; else if (ret) - spin = false; + poll_flags |= BLK_POLL_ONESHOT; /* iopoll may have completed current req */ if (READ_ONCE(req->iopoll_completed)) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 560ae967f70e..236aba256cd1 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -49,13 +49,13 @@ struct iomap_dio { }; }; -int iomap_dio_iopoll(struct kiocb *kiocb, bool spin) +int iomap_dio_iopoll(struct kiocb *kiocb, unsigned int flags) { struct request_queue *q = READ_ONCE(kiocb->private); if (!q) return 0; - return blk_poll(q, READ_ONCE(kiocb->ki_cookie), spin); + return blk_poll(q, READ_ONCE(kiocb->ki_cookie), flags); } EXPORT_SYMBOL_GPL(iomap_dio_iopoll); @@ -642,7 +642,7 @@ __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, true)) + dio->submit.cookie, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 17705c970d7e..e177346bc020 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -564,7 +564,9 @@ extern const char *blk_op_str(unsigned int op); 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, bool spin); +/* only poll the hardware once, don't continue until a completion was found */ +#define BLK_POLL_ONESHOT (1 << 0) +int blk_poll(struct request_queue *q, blk_qc_t cookie, unsigned int flags); static inline struct request_queue *bdev_get_queue(struct block_device *bdev) { diff --git a/include/linux/fs.h b/include/linux/fs.h index e7a633353fd2..c443cddf414f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2075,7 +2075,7 @@ struct file_operations { ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); - int (*iopoll)(struct kiocb *kiocb, bool spin); + int (*iopoll)(struct kiocb *kiocb, unsigned int flags); int (*iterate) (struct file *, struct dir_context *); int (*iterate_shared) (struct file *, struct dir_context *); __poll_t (*poll) (struct file *, struct poll_table_struct *); diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 24f8489583ca..1e86b65567c2 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -337,7 +337,7 @@ struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, unsigned int dio_flags); ssize_t iomap_dio_complete(struct iomap_dio *dio); -int iomap_dio_iopoll(struct kiocb *kiocb, bool spin); +int iomap_dio_iopoll(struct kiocb *kiocb, unsigned int flags); #ifdef CONFIG_SWAP struct file; diff --git a/mm/page_io.c b/mm/page_io.c index c493ce9ebcf5..5d5543fcefa4 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -428,7 +428,7 @@ int swap_readpage(struct page *page, bool synchronous) if (!READ_ONCE(bio->bi_private)) break; - if (!blk_poll(disk->queue, qc, true)) + if (!blk_poll(disk->queue, qc, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); -- 2.39.5