[dpdk-dev] [PATCH] examples/ipsec-secgw: limit inflight packets count

[Radu Nicolau <radu.nicolau@intel.com>]

Revert previous patch that introduce a performance
degradation in certain scenarios and add a configurable
limit for number inflight packets.

Revert
commit 84d4b5e4ec48 ("examples/ipsec-secgw: improve IPsec dequeue logic")
Cc: stable@dpdk.org

Signed-off-by: Radu Nicolau <radu.nicolau@intel.com>
---
 examples/ipsec-secgw/ipsec.c | 31 ++++++++++++++-----------------
 examples/ipsec-secgw/ipsec.h |  1 +
 2 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/examples/ipsec-secgw/ipsec.c b/examples/ipsec-secgw/ipsec.c
index 5fb5bc1..1b16b29 100644
--- a/examples/ipsec-secgw/ipsec.c
+++ b/examples/ipsec-secgw/ipsec.c
@@ -345,13 +345,18 @@ create_session(struct ipsec_ctx *ipsec_ctx, struct ipsec_sa *sa)
 static inline void
 enqueue_cop(struct cdev_qp *cqp, struct rte_crypto_op *cop)
 {
-	int32_t ret, i;
+	int32_t ret = 0, i;
 
 	cqp->buf[cqp->len++] = cop;
 
 	if (cqp->len == MAX_PKT_BURST) {
-		ret = rte_cryptodev_enqueue_burst(cqp->id, cqp->qp,
-				cqp->buf, cqp->len);
+		int enq_size = cqp->len;
+		if (cqp->in_flight >= MAX_INFLIGHT)
+			enq_size -= (int)(cqp->in_flight - MAX_INFLIGHT);
+
+		if (enq_size > 0)
+			ret = rte_cryptodev_enqueue_burst(cqp->id, cqp->qp,
+					cqp->buf, enq_size);
 		if (ret < cqp->len) {
 			RTE_LOG_DP(DEBUG, IPSEC, "Cryptodev %u queue %u:"
 					" enqueued %u crypto ops out of %u\n",
@@ -486,9 +491,12 @@ ipsec_dequeue(ipsec_xform_fn xform_func, struct ipsec_ctx *ipsec_ctx,
 	struct ipsec_sa *sa;
 	struct rte_mbuf *pkt;
 
-	for (i = 0; i < ipsec_ctx->nb_qps && nb_pkts < max_pkts;) {
+	for (i = 0; i < ipsec_ctx->nb_qps && nb_pkts < max_pkts; i++) {
 		struct cdev_qp *cqp;
-		cqp = &ipsec_ctx->tbl[ipsec_ctx->last_qp];
+
+		cqp = &ipsec_ctx->tbl[ipsec_ctx->last_qp++];
+		if (ipsec_ctx->last_qp == ipsec_ctx->nb_qps)
+			ipsec_ctx->last_qp %= ipsec_ctx->nb_qps;
 
 		while (ipsec_ctx->ol_pkts_cnt > 0 && nb_pkts < max_pkts) {
 			pkt = ipsec_ctx->ol_pkts[--ipsec_ctx->ol_pkts_cnt];
@@ -503,13 +511,8 @@ ipsec_dequeue(ipsec_xform_fn xform_func, struct ipsec_ctx *ipsec_ctx,
 			pkts[nb_pkts++] = pkt;
 		}
 
-		if (cqp->in_flight == 0) {
-			ipsec_ctx->last_qp++;
-			if (ipsec_ctx->last_qp == ipsec_ctx->nb_qps)
-				ipsec_ctx->last_qp %= ipsec_ctx->nb_qps;
-			i++;
+		if (cqp->in_flight == 0)
 			continue;
-		}
 
 		nb_cops = rte_cryptodev_dequeue_burst(cqp->id, cqp->qp,
 				cops, max_pkts - nb_pkts);
@@ -533,12 +536,6 @@ ipsec_dequeue(ipsec_xform_fn xform_func, struct ipsec_ctx *ipsec_ctx,
 				}
 			}
 			pkts[nb_pkts++] = pkt;
-			if (cqp->in_flight < max_pkts) {
-				ipsec_ctx->last_qp++;
-				if (ipsec_ctx->last_qp == ipsec_ctx->nb_qps)
-					ipsec_ctx->last_qp %= ipsec_ctx->nb_qps;
-				i++;
-			}
 		}
 	}
 
diff --git a/examples/ipsec-secgw/ipsec.h b/examples/ipsec-secgw/ipsec.h
index 6059f6c..9ce912e 100644
--- a/examples/ipsec-secgw/ipsec.h
+++ b/examples/ipsec-secgw/ipsec.h
@@ -17,6 +17,7 @@
 #define RTE_LOGTYPE_IPSEC_IPIP  RTE_LOGTYPE_USER3
 
 #define MAX_PKT_BURST 32
+#define MAX_INFLIGHT 128
 #define MAX_QP_PER_LCORE 256
 
 #define MAX_DIGEST_SIZE 32 /* Bytes -- 256 bits */
-- 
2.7.5