IB/hfi1: Prioritize the sending of ACK packets

ACK packets are generally associated with request completion and resource
release and therefore should be sent first. This patch optimizes the
send engine by using the following policies:
(1) QPs with RVT_S_ACK_PENDING bit set in qp->s_flags or qpriv->s_flags
should have their priority incremented;
(2) QPs with ACK or TID-ACK packet queued should have their priority
incremented;
(3) When a QP is queued to the wait list due to resource constraints, it
will be queued to the head if it has ACK packet to send;
(4) When selecting qps to run from the wait list, the one with the highest
priority and starve_cnt will be selected; each priority will be equivalent
to a fixed number of starve_cnt (16).

Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Kaike Wan
2019-01-23 21:52:19 -08:00
committed by Doug Ledford
parent a05c9bdcfd
commit 34025fb0c4
12 changed files with 144 additions and 51 deletions

View File

@@ -144,8 +144,10 @@ static int defer_packet_queue(
*/
xchg(&pq->state, SDMA_PKT_Q_DEFERRED);
write_seqlock(&sde->waitlock);
if (list_empty(&pq->busy.list))
if (list_empty(&pq->busy.list)) {
iowait_get_priority(&pq->busy);
iowait_queue(pkts_sent, &pq->busy, &sde->dmawait);
}
write_sequnlock(&sde->waitlock);
return -EBUSY;
eagain:
@@ -191,7 +193,7 @@ int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
pq->mm = fd->mm;
iowait_init(&pq->busy, 0, NULL, NULL, defer_packet_queue,
activate_packet_queue, NULL);
activate_packet_queue, NULL, NULL);
pq->reqidx = 0;
pq->reqs = kcalloc(hfi1_sdma_comp_ring_size,