From 34025fb0c4c9d6b2e294f8f8f0a82491a13c83a2 Mon Sep 17 00:00:00 2001 From: Kaike Wan Date: Wed, 23 Jan 2019 21:52:19 -0800 Subject: 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 Signed-off-by: Mike Marciniszyn Signed-off-by: Kaike Wan Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/pio.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'drivers/infiniband/hw/hfi1/pio.c') diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c index 04126d7e318d..a1de566fe95e 100644 --- a/drivers/infiniband/hw/hfi1/pio.c +++ b/drivers/infiniband/hw/hfi1/pio.c @@ -1599,8 +1599,7 @@ static void sc_piobufavail(struct send_context *sc) struct rvt_qp *qp; struct hfi1_qp_priv *priv; unsigned long flags; - uint i, n = 0, max_idx = 0; - u8 max_starved_cnt = 0; + uint i, n = 0, top_idx = 0; if (dd->send_contexts[sc->sw_index].type != SC_KERNEL && dd->send_contexts[sc->sw_index].type != SC_VL15) @@ -1619,11 +1618,18 @@ static void sc_piobufavail(struct send_context *sc) if (n == ARRAY_SIZE(qps)) break; wait = list_first_entry(list, struct iowait, list); + iowait_get_priority(wait); qp = iowait_to_qp(wait); priv = qp->priv; list_del_init(&priv->s_iowait.list); priv->s_iowait.lock = NULL; - iowait_starve_find_max(wait, &max_starved_cnt, n, &max_idx); + if (n) { + priv = qps[top_idx]->priv; + top_idx = iowait_priority_update_top(wait, + &priv->s_iowait, + n, top_idx); + } + /* refcount held until actual wake up */ qps[n++] = qp; } @@ -1638,12 +1644,12 @@ static void sc_piobufavail(struct send_context *sc) } write_sequnlock_irqrestore(&sc->waitlock, flags); - /* Wake up the most starved one first */ + /* Wake up the top-priority one first */ if (n) - hfi1_qp_wakeup(qps[max_idx], + hfi1_qp_wakeup(qps[top_idx], RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN); for (i = 0; i < n; i++) - if (i != max_idx) + if (i != top_idx) hfi1_qp_wakeup(qps[i], RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN); } -- cgit v1.2.3