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authorJan Kara <jack@suse.cz>2021-01-11 17:47:16 +0100
committerJens Axboe <axboe@kernel.dk>2021-01-24 18:19:46 -0700
commit5ac83c644f5fb924f0b2c09102ab82fc788f8411 (patch)
tree44ecf60a95b280219d2872c1dec05a3f6f9a7e72 /block/mq-deadline.c
parent2391d13ed484df1515f0025458e1f82317823fab (diff)
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Revert "blk-mq, elevator: Count requests per hctx to improve performance"
This reverts commit b445547ec1bbd3e7bf4b1c142550942f70527d95. Since both mq-deadline and BFQ completely ignore hctx they are passed to their dispatch function and dispatch whatever request they deem fit checking whether any request for a particular hctx is queued is just pointless since we'll very likely get a request from a different hctx anyway. In the following commit we'll deal with lock contention in these IO schedulers in presence of multiple HW queues in a different way. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/mq-deadline.c')
-rw-r--r--block/mq-deadline.c6
1 files changed, 0 insertions, 6 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 800ac902809b..b57470e154c8 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -386,8 +386,6 @@ static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
spin_lock(&dd->lock);
rq = __dd_dispatch_request(dd);
spin_unlock(&dd->lock);
- if (rq)
- atomic_dec(&rq->mq_hctx->elevator_queued);
return rq;
}
@@ -535,7 +533,6 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
rq = list_first_entry(list, struct request, queuelist);
list_del_init(&rq->queuelist);
dd_insert_request(hctx, rq, at_head);
- atomic_inc(&hctx->elevator_queued);
}
spin_unlock(&dd->lock);
}
@@ -582,9 +579,6 @@ static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
{
struct deadline_data *dd = hctx->queue->elevator->elevator_data;
- if (!atomic_read(&hctx->elevator_queued))
- return false;
-
return !list_empty_careful(&dd->dispatch) ||
!list_empty_careful(&dd->fifo_list[0]) ||
!list_empty_careful(&dd->fifo_list[1]);