If we want to support async IO polling, then we have to allow
finding completions that aren't just for the one we are
looking for. Always pass in -1 to the mq_ops->poll() helper,
and have that return how many events were found in this poll
loop.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
block/blk-mq.c | 69 +++++++++++++++++++++++------------------
drivers/nvme/host/pci.c | 14 ++++-----
2 files changed, 46 insertions(+), 37 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 52b1c97cd7c6..3ca00d712158 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3266,9 +3266,7 @@ static bool blk_mq_poll_hybrid_sleep(struct request_queue *q,
* 0: use half of prev avg
* >0: use this specific value
*/
- if (q->poll_nsec == -1)
- return false;
- else if (q->poll_nsec > 0)
+ if (q->poll_nsec > 0)
nsecs = q->poll_nsec;
else
nsecs = blk_mq_poll_nsecs(q, hctx, rq);
@@ -3305,21 +3303,36 @@ static bool blk_mq_poll_hybrid_sleep(struct request_queue *q,
return true;
}
-static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static bool blk_mq_poll_hybrid(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx, blk_qc_t cookie)
+{
+ struct request *rq;
+
+ if (q->poll_nsec == -1)
+ return false;
+
+ if (!blk_qc_t_is_internal(cookie))
+ rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
+ else {
+ rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie));
+ /*
+ * With scheduling, if the request has completed, we'll
+ * get a NULL return here, as we clear the sched tag when
+ * that happens. The request still remains valid, like always,
+ * so we should be safe with just the NULL check.
+ */
+ if (!rq)
+ return false;
+ }
+
+ return blk_mq_poll_hybrid_sleep(q, hctx, rq);
+}
+
+static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
long state;
- /*
- * If we sleep, have the caller restart the poll loop to reset
- * the state. Like for the other success return cases, the
- * caller is responsible for checking if the IO completed. If
- * the IO isn't complete, we'll get called again and will go
- * straight to the busy poll loop.
- */
- if (blk_mq_poll_hybrid_sleep(q, hctx, rq))
- return 1;
-
hctx->poll_considered++;
state = current->state;
@@ -3328,7 +3341,7 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
hctx->poll_invoked++;
- ret = q->mq_ops->poll(hctx, rq->tag);
+ ret = q->mq_ops->poll(hctx, -1U);
if (ret > 0) {
hctx->poll_success++;
__set_current_state(TASK_RUNNING);
@@ -3352,27 +3365,23 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
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 0;
hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
- if (!blk_qc_t_is_internal(cookie))
- rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
- else {
- rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie));
- /*
- * With scheduling, if the request has completed, we'll
- * get a NULL return here, as we clear the sched tag when
- * that happens. The request still remains valid, like always,
- * so we should be safe with just the NULL check.
- */
- if (!rq)
- return 0;
- }
- return __blk_mq_poll(hctx, rq);
+ /*
+ * If we sleep, have the caller restart the poll loop to reset
+ * the state. Like for the other success return cases, the
+ * caller is responsible for checking if the IO completed. If
+ * the IO isn't complete, we'll get called again and will go
+ * straight to the busy poll loop.
+ */
+ if (blk_mq_poll_hybrid(q, hctx, cookie))
+ return 1;
+
+ return __blk_mq_poll(hctx);
}
unsigned int blk_mq_rq_cpu(struct request *rq)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index fc7dd49f22fc..6c03461ad988 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1012,15 +1012,15 @@ static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
}
}
-static inline bool nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
- u16 *end, int tag)
+static inline int nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
+ u16 *end, unsigned int tag)
{
- bool found = false;
+ int found = 0;
*start = nvmeq->cq_head;
- while (!found && nvme_cqe_pending(nvmeq)) {
- if (nvmeq->cqes[nvmeq->cq_head].command_id == tag)
- found = true;
+ while (nvme_cqe_pending(nvmeq)) {
+ if (tag == -1U || nvmeq->cqes[nvmeq->cq_head].command_id == tag)
+ found++;
nvme_update_cq_head(nvmeq);
}
*end = nvmeq->cq_head;
@@ -1062,7 +1062,7 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
{
u16 start, end;
- bool found;
+ int found;
if (!nvme_cqe_pending(nvmeq))
return 0;
--
2.17.1
