[08/16] block: replace the spin argument to blk_iopoll with a flags argument

Message ID	20210615131034.752623-9-hch@lst.de (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-fsdevel-owner@kernel.org> From: Christoph Hellwig <hch@lst.de> To: Jens Axboe <axboe@kernel.dk> Cc: Jeffle Xu <jefflexu@linux.alibaba.com>, Ming Lei <ming.lei@redhat.com>, Damien Le Moal <Damien.LeMoal@wdc.com>, Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>, "Wunderlich, Mark" <mark.wunderlich@intel.com>, "Vasudevan, Anil" <anil.vasudevan@intel.com>, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvme@lists.infradead.org Subject: [PATCH 08/16] block: replace the spin argument to blk_iopoll with a flags argument Date: Tue, 15 Jun 2021 15:10:26 +0200 Message-Id: <20210615131034.752623-9-hch@lst.de> In-Reply-To: <20210615131034.752623-1-hch@lst.de> References: <20210615131034.752623-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	[01/16] direct-io: remove blk_poll support \| expand [01/16] direct-io: remove blk_poll support [02/16] block: don't try to poll multi-bio I/Os in __blkdev_direct_IO [03/16] iomap: don't try to poll multi-bio I/Os in __iomap_dio_rw [04/16] blk-mq: factor out a blk_qc_to_hctx helper [05/16] blk-mq: factor out a "classic" poll helper [06/16] blk-mq: remove blk_qc_t_to_tag and blk_qc_t_is_internal [07/16] blk-mq: remove blk_qc_t_valid [08/16] block: replace the spin argument to blk_iopoll with a flags argument [09/16] io_uring: don't sleep when polling for I/O [10/16] block: rename REQ_HIPRI to REQ_POLLED [11/16] block: use SLAB_TYPESAFE_BY_RCU for the bio slab [12/16] block: define 'struct bvec_iter' as packed [13/16] block: switch polling to be bio based [14/16] block: don't allow writing to the poll queue attribute [15/16] nvme-multipath: set QUEUE_FLAG_NOWAIT [16/16] nvme-multipath: enable polled I/O

diff --git a/block/blk-mq.c b/block/blk-mq.c index cb94cf9bcf99..c2b2c7abd712 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3951,7 +3951,7 @@ 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 = current->state; @@ -3974,7 +3974,7 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, if (current->state == TASK_RUNNING) return 1; - if (ret < 0 || !spin) + if (ret < 0 || (flags & BLK_POLL_ONESHOT)) break; cpu_relax(); } while (!need_resched()); @@ -3987,15 +3987,13 @@ 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)) @@ -4004,12 +4002,11 @@ 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/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 24bcae88587a..115c8d90530a 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1032,7 +1032,7 @@ static void nvme_execute_rq_polled(struct request_queue *q, blk_execute_rq_nowait(bd_disk, rq, at_head, nvme_end_sync_rq); while (!completion_done(&wait)) { - blk_poll(q, request_to_qc_t(rq->mq_hctx, rq), true); + blk_poll(q, request_to_qc_t(rq->mq_hctx, rq), 0); cond_resched(); } } diff --git a/fs/block_dev.c b/fs/block_dev.c index 8600c651b0b0..c9bdaa138909 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -286,7 +286,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, 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); @@ -319,12 +319,12 @@ 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) @@ -475,7 +475,7 @@ 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 5f82954004f6..de8d39e9a154 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2290,18 +2290,18 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, long min) { + unsigned int poll_flags = 0; struct io_kiocb *req, *tmp; LIST_HEAD(done); - bool spin; - int ret; + int ret = 0; /* * 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_file && *nr_events < min; + if (ctx->poll_multi_file || *nr_events >= min) + poll_flags |= BLK_POLL_ONESHOT; - ret = 0; list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { struct kiocb *kiocb = &req->rw.kiocb; @@ -2317,7 +2317,7 @@ 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 (ret < 0) break; @@ -2325,8 +2325,8 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, if (READ_ONCE(req->iopoll_completed)) list_move_tail(&req->inflight_entry, &done); - if (ret && spin) - spin = false; + if (ret) + poll_flags |= BLK_POLL_ONESHOT; ret = 0; } diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index d5637f467109..9b6c26da3a2d 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); @@ -640,7 +640,7 @@ __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 d66d0da72529..c7061f25ee5f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -946,7 +946,9 @@ 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 c3c88fdb9b2a..483fb557d92f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2026,7 +2026,7 @@ 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 c87d0cb0de6d..56e5949ccb60 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -275,7 +275,7 @@ 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);

[08/16] block: replace the spin argument to blk_iopoll with a flags argument

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