From: Alan Robertson <ar7...@att.com>
There were 2 issues, the first was time could be lost whilst updating
the traffic-class period, the second was a frame could be delayed if
not enough tokens were available for the full frame. By allowing the
shaper to borrow credit from the next period the throughput is improved.
---
lib/librte_sched/rte_sched.c | 58 +++++++++++++++++++++++++++++++-------------
1 file changed, 41 insertions(+), 17 deletions(-)
diff --git a/lib/librte_sched/rte_sched.c b/lib/librte_sched/rte_sched.c
index 634486c..e53a424 100644
--- a/lib/librte_sched/rte_sched.c
+++ b/lib/librte_sched/rte_sched.c
@@ -57,7 +57,7 @@ struct rte_sched_subport {
/* Traffic classes (TCs) */
uint64_t tc_time; /* time of next update */
uint32_t tc_credits_per_period[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
- uint32_t tc_credits[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
+ int32_t tc_credits[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
uint32_t tc_period;
/* TC oversubscription */
@@ -98,7 +98,7 @@ struct rte_sched_pipe {
/* Traffic classes (TCs) */
uint64_t tc_time; /* time of next update */
- uint32_t tc_credits[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
+ int32_t tc_credits[RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE];
/* Weighted Round Robin (WRR) */
uint8_t wrr_tokens[RTE_SCHED_QUEUES_PER_PIPE];
@@ -1451,6 +1451,8 @@ grinder_credits_update(struct rte_sched_port *port,
uint32_t pos)
struct rte_sched_pipe *pipe = grinder->pipe;
struct rte_sched_pipe_profile *params = grinder->pipe_params;
uint64_t n_periods;
+ uint32_t tc;
+ uint64_t lapsed;
/* Subport TB */
n_periods = (port->time - subport->tb_time) / subport->tb_period;
@@ -1466,20 +1468,42 @@ grinder_credits_update(struct rte_sched_port *port,
uint32_t pos)
/* Subport TCs */
if (unlikely(port->time >= subport->tc_time)) {
- subport->tc_credits[0] = subport->tc_credits_per_period[0];
- subport->tc_credits[1] = subport->tc_credits_per_period[1];
- subport->tc_credits[2] = subport->tc_credits_per_period[2];
- subport->tc_credits[3] = subport->tc_credits_per_period[3];
- subport->tc_time = port->time + subport->tc_period;
+ for (tc = 0; tc < RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE; tc++) {
+ if (subport->tc_credits[tc] < 0)
+ subport->tc_credits[tc] +=
+ subport->tc_credits_per_period[tc];
+ else
+ subport->tc_credits[tc] =
+ subport->tc_credits_per_period[tc];
+ }
+ /* If we've run into the next period only update the clock to
+ * the time + tc_period so we'll replenish the tc tokens early
+ * in the next tc_period to compensate. */
+ lapsed = port->time - subport->tc_time;
+ if (lapsed < subport->tc_period)
+ subport->tc_time += subport->tc_period;
+ else
+ subport->tc_time = port->time + subport->tc_period;
}
/* Pipe TCs */
if (unlikely(port->time >= pipe->tc_time)) {
- pipe->tc_credits[0] = params->tc_credits_per_period[0];
- pipe->tc_credits[1] = params->tc_credits_per_period[1];
- pipe->tc_credits[2] = params->tc_credits_per_period[2];
- pipe->tc_credits[3] = params->tc_credits_per_period[3];
- pipe->tc_time = port->time + params->tc_period;
+ for (tc = 0; tc < RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE; tc++) {
+ if (pipe->tc_credits[tc] < 0)
+ pipe->tc_credits[tc] +=
+ params->tc_credits_per_period[tc];
+ else
+ pipe->tc_credits[tc] =
+ params->tc_credits_per_period[tc];
+ }
+ /* If we've run into the next period only update the clock to
+ * the time + tc_period so we'll replenish the tc tokens early
+ * in the next tc_period to compensate. */
+ lapsed = port->time - pipe->tc_time;
+ if (lapsed < params->tc_period)
+ pipe->tc_time += params->tc_period;
+ else
+ pipe->tc_time = port->time + params->tc_period;
}
}
@@ -1586,16 +1610,16 @@ grinder_credits_check(struct rte_sched_port *port,
uint32_t pos)
uint32_t tc_index = grinder->tc_index;
uint32_t pkt_len = pkt->pkt_len + port->frame_overhead;
uint32_t subport_tb_credits = subport->tb_credits;
- uint32_t subport_tc_credits = subport->tc_credits[tc_index];
+ int32_t subport_tc_credits = subport->tc_credits[tc_index];
uint32_t pipe_tb_credits = pipe->tb_credits;
- uint32_t pipe_tc_credits = pipe->tc_credits[tc_index];
+ int32_t pipe_tc_credits = pipe->tc_credits[tc_index];
int enough_credits;
/* Check queue credits */
enough_credits = (pkt_len <= subport_tb_credits) &&
- (pkt_len <= subport_tc_credits) &&
+ (subport_tc_credits > 0) &&
(pkt_len <= pipe_tb_credits) &&
- (pkt_len <= pipe_tc_credits);
+ (pipe_tc_credits > 0);
if (!enough_credits)
return 0;
@@ -1603,8 +1627,8 @@ grinder_credits_check(struct rte_sched_port *port,
uint32_t pos)
/* Update port credits */
subport->tb_credits -= pkt_len;
subport->tc_credits[tc_index] -= pkt_len;
- pipe->tb_credits -= pkt_len;
pipe->tc_credits[tc_index] -= pkt_len;
+ pipe->tb_credits -= pkt_len;
return 1;
}
--
2.7.4
