From 35118adb8d4ab3a7ccee04f0f119d98fcdfc1858 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 6 Nov 2018 13:30:55 -0700 Subject: [PATCH] block: have ->poll_fn() return number of entries polled commit 85f4d4b65fdd67f1d6dc9eeb1d91923cef07eb6a upstream. We currently only really support sync poll, ie poll with 1 IO in flight. This prepares us for supporting async poll. Note that the returned value isn't necessarily 100% accurate. If poll races with IRQ completion, we assume that the fact that the task is now runnable means we found at least one entry. In reality it could be more than 1, or not even 1. This is fine, the caller will just need to take this into account. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Joseph Qi Reviewed-by: Xiaoguang Wang Acked-by: Caspar Zhang --- block/blk-mq.c | 18 +++++++++--------- drivers/nvme/host/multipath.c | 4 ++-- include/linux/blkdev.h | 2 +- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 39e2e4621472..8e11dd8e9b8d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -37,7 +37,7 @@ #include "blk-mq-sched.h" #include "blk-rq-qos.h" -static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie); +static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie); static void blk_mq_poll_stats_start(struct request_queue *q); static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); @@ -3157,7 +3157,7 @@ static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, return true; } -static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) +static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) { struct request_queue *q = hctx->queue; long state; @@ -3170,7 +3170,7 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) * straight to the busy poll loop. */ if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) - return true; + return 1; hctx->poll_considered++; @@ -3184,30 +3184,30 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) if (ret > 0) { hctx->poll_success++; set_current_state(TASK_RUNNING); - return true; + return ret; } if (signal_pending_state(state, current)) set_current_state(TASK_RUNNING); if (current->state == TASK_RUNNING) - return true; + return 1; if (ret < 0) break; cpu_relax(); } __set_current_state(TASK_RUNNING); - return false; + return 0; } -static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) +static int blk_mq_poll(struct request_queue *q, blk_qc_t cookie) { struct blk_mq_hw_ctx *hctx; struct request *rq; if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) - return false; + return 0; hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; if (!blk_qc_t_is_internal(cookie)) @@ -3221,7 +3221,7 @@ static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) * so we should be safe with just the NULL check. */ if (!rq) - return false; + return 0; } return __blk_mq_poll(hctx, rq); diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 838ee58d80cd..cc44d5ea2e12 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -217,11 +217,11 @@ static blk_qc_t nvme_ns_head_make_request(struct request_queue *q, return ret; } -static bool 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) { struct nvme_ns_head *head = q->queuedata; struct nvme_ns *ns; - bool found = false; + int found = 0; int srcu_idx; srcu_idx = srcu_read_lock(&head->srcu); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 41c201496cbc..c4d0f8a97bd9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -317,7 +317,7 @@ struct blk_queue_ctx; typedef void (request_fn_proc) (struct request_queue *q); typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio); -typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t); +typedef int (poll_q_fn) (struct request_queue *q, blk_qc_t); typedef int (prep_rq_fn) (struct request_queue *, struct request *); typedef void (unprep_rq_fn) (struct request_queue *, struct request *); -- GitLab