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authorChengming Zhou <zhouchengming@bytedance.com>2023-09-13 15:16:12 +0000
committerJens Axboe <axboe@kernel.dk>2023-09-22 08:52:13 -0600
commitb8643d682669994b3f57c3440df3d4f9cb735f35 (patch)
tree35b49bc8dc17365c9e7dcbc74c71ee6cde581321 /block/blk-mq.c
parentce9ecca0238b140b88f43859b211c9fdfd8e5b70 (diff)
blk-mq: account active requests when get driver tag
There is a limit that batched queue_rqs() can't work on shared tags queue, since the account of active requests can't be done there. Now we account the active requests only in blk_mq_get_driver_tag(), which is not the time we get driver tag actually (with none elevator). To support batched queue_rqs() on shared tags queue, we move the account of active requests to where we get the driver tag: 1. none elevator: blk_mq_get_tags() and blk_mq_get_tag() 2. other elevator: __blk_mq_alloc_driver_tag() This is clearer and match with the unaccount side, which just happen when we put the driver tag. The other good point is that we don't need RQF_MQ_INFLIGHT trick anymore, which used to avoid double account of flush request. Now we only account when actually get the driver tag, so all is good. We will remove RQF_MQ_INFLIGHT in the next patch. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230913151616.3164338-2-chengming.zhou@linux.dev Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c33
1 files changed, 12 insertions, 21 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1fafd54dce3c..e776388decc3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -426,6 +426,8 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data)
rq_list_add(data->cached_rq, rq);
nr++;
}
+ if (!(data->rq_flags & RQF_SCHED_TAGS))
+ blk_mq_add_active_requests(data->hctx, nr);
/* caller already holds a reference, add for remainder */
percpu_ref_get_many(&data->q->q_usage_counter, nr - 1);
data->nr_tags -= nr;
@@ -510,6 +512,8 @@ retry:
goto retry;
}
+ if (!(data->rq_flags & RQF_SCHED_TAGS))
+ blk_mq_inc_active_requests(data->hctx);
rq = blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag);
blk_mq_rq_time_init(rq, alloc_time_ns);
return rq;
@@ -669,6 +673,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
tag = blk_mq_get_tag(&data);
if (tag == BLK_MQ_NO_TAG)
goto out_queue_exit;
+ if (!(data.rq_flags & RQF_SCHED_TAGS))
+ blk_mq_inc_active_requests(data.hctx);
rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag);
blk_mq_rq_time_init(rq, alloc_time_ns);
rq->__data_len = 0;
@@ -708,11 +714,10 @@ static void __blk_mq_free_request(struct request *rq)
blk_pm_mark_last_busy(rq);
rq->mq_hctx = NULL;
- if (rq->rq_flags & RQF_MQ_INFLIGHT)
- __blk_mq_dec_active_requests(hctx);
-
- if (rq->tag != BLK_MQ_NO_TAG)
+ if (rq->tag != BLK_MQ_NO_TAG) {
+ blk_mq_dec_active_requests(hctx);
blk_mq_put_tag(hctx->tags, ctx, rq->tag);
+ }
if (sched_tag != BLK_MQ_NO_TAG)
blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag);
blk_mq_sched_restart(hctx);
@@ -1065,8 +1070,7 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx,
* All requests should have been marked as RQF_MQ_INFLIGHT, so
* update hctx->nr_active in batch
*/
- if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
- __blk_mq_sub_active_requests(hctx, nr_tags);
+ blk_mq_sub_active_requests(hctx, nr_tags);
blk_mq_put_tags(hctx->tags, tag_array, nr_tags);
percpu_ref_put_many(&q->q_usage_counter, nr_tags);
@@ -1748,7 +1752,7 @@ struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
return data.rq;
}
-static bool __blk_mq_alloc_driver_tag(struct request *rq)
+bool __blk_mq_alloc_driver_tag(struct request *rq)
{
struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
@@ -1769,20 +1773,7 @@ static bool __blk_mq_alloc_driver_tag(struct request *rq)
return false;
rq->tag = tag + tag_offset;
- return true;
-}
-
-bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq)
-{
- if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
- return false;
-
- if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) &&
- !(rq->rq_flags & RQF_MQ_INFLIGHT)) {
- rq->rq_flags |= RQF_MQ_INFLIGHT;
- __blk_mq_inc_active_requests(hctx);
- }
- hctx->tags->rqs[rq->tag] = rq;
+ blk_mq_inc_active_requests(rq->mq_hctx);
return true;
}