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* [dpdk-dev] [PATCH] meter: fix excess token bucket update in srtcm implementation
@ 2016-09-07  6:15 Nikhil Jagtap
  2016-09-19 15:51 ` Dumitrescu, Cristian
  2016-09-21  5:57 ` [dpdk-dev] [PATCH v2] " Nikhil Jagtap
  0 siblings, 2 replies; 6+ messages in thread
From: Nikhil Jagtap @ 2016-09-07  6:15 UTC (permalink / raw)
  To: cristian.dumitrescu; +Cc: dev, kannan.babu.ramia, Nikhil Jagtap

As per srTCM RFC 2697, we should be updating the E bucket only after the
C bucket overflows. This patch fixes the current DPDK implementation,
where we are updating both the buckets simultaneously at the same rate
(CIR) which results in token accumulation rate of (2*CIR).

Signed-off-by: Nikhil Jagtap <nikhil.jagtap@gmail.com>
---
 lib/librte_meter/rte_meter.h |   26 ++++++++++++++++----------
 1 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/lib/librte_meter/rte_meter.h b/lib/librte_meter/rte_meter.h
index 2cd8d81..0ffcb60 100644
--- a/lib/librte_meter/rte_meter.h
+++ b/lib/librte_meter/rte_meter.h
@@ -232,13 +232,16 @@ rte_meter_srtcm_color_blind_check(struct rte_meter_srtcm *m,
 	n_periods = time_diff / m->cir_period;
 	m->time += n_periods * m->cir_period;
 
+	/* Put the tokens overflowing from tc into te bucket */
 	tc = m->tc + n_periods * m->cir_bytes_per_period;
-	if (tc > m->cbs)
+	if (tc > m->cbs) {
+		te = m->te + (tc - m->cbs);
+		if (te > m->ebs)
+			te = m->ebs;
 		tc = m->cbs;
-
-	te = m->te + n_periods * m->cir_bytes_per_period;
-	if (te > m->ebs)
-		te = m->ebs;
+	} else {
+		te = m->te;
+	}
 
 	/* Color logic */
 	if (tc >= pkt_len) {
@@ -271,13 +274,16 @@ rte_meter_srtcm_color_aware_check(struct rte_meter_srtcm *m,
 	n_periods = time_diff / m->cir_period;
 	m->time += n_periods * m->cir_period;
 
+	/* Put the tokens overflowing from tc into te bucket */
 	tc = m->tc + n_periods * m->cir_bytes_per_period;
-	if (tc > m->cbs)
+	if (tc > m->cbs) {
+		te = m->te + (tc - m->cbs);
+		if (te > m->ebs)
+			te = m->ebs;
 		tc = m->cbs;
-
-	te = m->te + n_periods * m->cir_bytes_per_period;
-	if (te > m->ebs)
-		te = m->ebs;
+	} else {
+		te = m->te;
+	}
 
 	/* Color logic */
 	if ((pkt_color == e_RTE_METER_GREEN) && (tc >= pkt_len)) {
-- 
1.7.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-09-21 21:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-07  6:15 [dpdk-dev] [PATCH] meter: fix excess token bucket update in srtcm implementation Nikhil Jagtap
2016-09-19 15:51 ` Dumitrescu, Cristian
2016-09-20  4:40   ` Nikhil Jagtap
2016-09-21  5:57 ` [dpdk-dev] [PATCH v2] " Nikhil Jagtap
2016-09-21  8:57   ` Dumitrescu, Cristian
2016-09-21 21:19     ` Thomas Monjalon

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