[dpdk-dev] [PATCH v3 2/3] port: add kni nodrop writer

[WeiJie Zhuang]

1. add no drop writing operations to the kni port
2. support dropless kni config in the ip pipeline sample application

Signed-off-by: WeiJie Zhuang <zhuangwj at gmail.com>
---
 examples/ip_pipeline/app.h           |   2 +
 examples/ip_pipeline/config_parse.c  |  31 ++++-
 examples/ip_pipeline/init.c          |  26 ++++-
 examples/ip_pipeline/pipeline_be.h   |   6 +
 lib/librte_port/rte_port_kni.c       | 220 +++++++++++++++++++++++++++++++++++
 lib/librte_port/rte_port_kni.h       |  13 +++
 lib/librte_port/rte_port_version.map |   1 +
 7 files changed, 292 insertions(+), 7 deletions(-)

diff --git a/examples/ip_pipeline/app.h b/examples/ip_pipeline/app.h
index abbd6d4..6a6fdd9 100644
--- a/examples/ip_pipeline/app.h
+++ b/examples/ip_pipeline/app.h
@@ -147,6 +147,8 @@ struct app_pktq_kni_params {
 	uint32_t mempool_id; /* Position in the app->mempool_params */
 	uint32_t burst_read;
 	uint32_t burst_write;
+	uint32_t dropless;
+	uint64_t n_retries;
 };
 
 #ifndef APP_FILE_NAME_SIZE
diff --git a/examples/ip_pipeline/config_parse.c b/examples/ip_pipeline/config_parse.c
index c55be31..31a50c2 100644
--- a/examples/ip_pipeline/config_parse.c
+++ b/examples/ip_pipeline/config_parse.c
@@ -199,6 +199,8 @@ struct app_pktq_kni_params default_kni_params = {
 	.mempool_id = 0,
 	.burst_read = 32,
 	.burst_write = 32,
+	.dropless = 0,
+	.n_retries = 0,
 };
 
 struct app_pktq_source_params default_source_params = {
@@ -1927,7 +1929,7 @@ parse_kni(struct app_params *app,
 
 		if (strcmp(ent->name, "mempool") == 0) {
 			int status = validate_name(ent->value,
-									   "MEMPOOL", 1);
+				"MEMPOOL", 1);
 			ssize_t idx;
 
 			PARSE_ERROR((status == 0), section_name,
@@ -1940,7 +1942,7 @@ parse_kni(struct app_params *app,
 
 		if (strcmp(ent->name, "burst_read") == 0) {
 			int status = parser_read_uint32(&param->burst_read,
-											ent->value);
+						ent->value);
 
 			PARSE_ERROR((status == 0), section_name,
 						ent->name);
@@ -1949,7 +1951,25 @@ parse_kni(struct app_params *app,
 
 		if (strcmp(ent->name, "burst_write") == 0) {
 			int status = parser_read_uint32(&param->burst_write,
-											ent->value);
+						ent->value);
+
+			PARSE_ERROR((status == 0), section_name,
+						ent->name);
+			continue;
+		}
+
+		if (strcmp(ent->name, "dropless") == 0) {
+			int status = parser_read_arg_bool(ent->value);
+
+			PARSE_ERROR((status != -EINVAL), section_name,
+						ent->name);
+			param->dropless = status;
+			continue;
+		}
+
+		if (strcmp(ent->name, "n_retries") == 0) {
+			int status = parser_read_uint64(&param->n_retries,
+						ent->value);
 
 			PARSE_ERROR((status == 0), section_name,
 						ent->name);
@@ -2794,6 +2814,11 @@ save_kni_params(struct app_params *app, FILE *f)
 		/* burst_write */
 		fprintf(f, "%s = %" PRIu32 "\n", "burst_write", p->burst_write);
 
+		/* dropless */
+		fprintf(f, "%s = %s\n",
+				"dropless",
+				p->dropless ? "yes" : "no");
+
 		fputc('\n', f);
 	}
 }
diff --git a/examples/ip_pipeline/init.c b/examples/ip_pipeline/init.c
index d522de4..af24f52 100644
--- a/examples/ip_pipeline/init.c
+++ b/examples/ip_pipeline/init.c
@@ -1434,10 +1434,28 @@ void app_pipeline_params_get(struct app_params *app,
 #ifdef RTE_LIBRTE_KNI
 		case APP_PKTQ_OUT_KNI:
 		{
-			out->type = PIPELINE_PORT_OUT_KNI_WRITER;
-			out->params.kni.kni = app->kni[in->id];
-			out->params.kni.tx_burst_sz =
-				app->kni_params[in->id].burst_write;
+			struct app_pktq_kni_params *p_kni =
+				&app->kni_params[in->id];
+
+			if (p_kni->dropless == 0) {
+				struct rte_port_kni_writer_params *params =
+					&out->params.kni;
+
+				out->type = PIPELINE_PORT_OUT_KNI_WRITER;
+				params->kni = app->kni[in->id];
+				params->tx_burst_sz =
+					app->kni_params[in->id].burst_write;
+			} else {
+				struct rte_port_kni_writer_nodrop_params
+					*params = &out->params.kni_nodrop;
+
+				out->type = PIPELINE_PORT_OUT_KNI_WRITER_NODROP;
+				params->kni = app->kni[in->id];
+				params->tx_burst_sz =
+					app->kni_params[in->id].burst_write;
+				params->n_retries =
+					app->kni_params[in->id].n_retries;
+			}
 			break;
 		}
 #endif /* RTE_LIBRTE_KNI */
diff --git a/examples/ip_pipeline/pipeline_be.h b/examples/ip_pipeline/pipeline_be.h
index 0ee208c..b562472 100644
--- a/examples/ip_pipeline/pipeline_be.h
+++ b/examples/ip_pipeline/pipeline_be.h
@@ -138,6 +138,7 @@ enum pipeline_port_out_type {
 	PIPELINE_PORT_OUT_RING_WRITER_IPV6_RAS,
 	PIPELINE_PORT_OUT_SCHED_WRITER,
 	PIPELINE_PORT_OUT_KNI_WRITER,
+	PIPELINE_PORT_OUT_KNI_WRITER_NODROP,
 	PIPELINE_PORT_OUT_SINK,
 };
 
@@ -155,6 +156,7 @@ struct pipeline_port_out_params {
 		struct rte_port_sched_writer_params sched;
 #ifdef RTE_LIBRTE_KNI
 		struct rte_port_kni_writer_params kni;
+		struct rte_port_kni_writer_nodrop_params kni_nodrop;
 #endif
 		struct rte_port_sink_params sink;
 	} params;
@@ -185,6 +187,8 @@ pipeline_port_out_params_convert(struct pipeline_port_out_params  *p)
 #ifdef RTE_LIBRTE_KNI
 	case PIPELINE_PORT_OUT_KNI_WRITER:
 		return (void *) &p->params.kni;
+	case PIPELINE_PORT_OUT_KNI_WRITER_NODROP:
+		return (void *) &p->params.kni_nodrop;
 #endif
 	case PIPELINE_PORT_OUT_SINK:
 		return (void *) &p->params.sink;
@@ -218,6 +222,8 @@ pipeline_port_out_params_get_ops(struct pipeline_port_out_params  *p)
 #ifdef RTE_LIBRTE_KNI
 	case PIPELINE_PORT_OUT_KNI_WRITER:
 		return &rte_port_kni_writer_ops;
+	case PIPELINE_PORT_OUT_KNI_WRITER_NODROP:
+		return &rte_port_kni_writer_nodrop_ops;
 #endif
 	case PIPELINE_PORT_OUT_SINK:
 		return &rte_port_sink_ops;
diff --git a/lib/librte_port/rte_port_kni.c b/lib/librte_port/rte_port_kni.c
index 4cbc345..08f4ac2 100644
--- a/lib/librte_port/rte_port_kni.c
+++ b/lib/librte_port/rte_port_kni.c
@@ -306,6 +306,217 @@ static int rte_port_kni_writer_stats_read(void *port,
 }
 
 /*
+ * Port KNI Writer Nodrop
+ */
+#ifdef RTE_PORT_STATS_COLLECT
+
+#define RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_IN_ADD(port, val) \
+	port->stats.n_pkts_in += val
+#define RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_DROP_ADD(port, val) \
+	port->stats.n_pkts_drop += val
+
+#else
+
+#define RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_IN_ADD(port, val)
+#define RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_DROP_ADD(port, val)
+
+#endif
+
+struct rte_port_kni_writer_nodrop {
+	struct rte_port_out_stats stats;
+
+	struct rte_mbuf *tx_buf[2 * RTE_PORT_IN_BURST_SIZE_MAX];
+	uint32_t tx_burst_sz;
+	uint32_t tx_buf_count;
+	uint64_t bsz_mask;
+	uint64_t n_retries;
+	struct rte_kni *kni;
+};
+
+static void *
+rte_port_kni_writer_nodrop_create(void *params, int socket_id)
+{
+	struct rte_port_kni_writer_nodrop_params *conf =
+		(struct rte_port_kni_writer_nodrop_params *) params;
+	struct rte_port_kni_writer_nodrop *port;
+
+	/* Check input parameters */
+	if ((conf == NULL) ||
+		(conf->tx_burst_sz == 0) ||
+		(conf->tx_burst_sz > RTE_PORT_IN_BURST_SIZE_MAX) ||
+		(!rte_is_power_of_2(conf->tx_burst_sz))) {
+		RTE_LOG(ERR, PORT, "%s: Invalid input parameters\n", __func__);
+		return NULL;
+	}
+
+	/* Memory allocation */
+	port = rte_zmalloc_socket("PORT", sizeof(*port),
+		RTE_CACHE_LINE_SIZE, socket_id);
+	if (port == NULL) {
+		RTE_LOG(ERR, PORT, "%s: Failed to allocate port\n", __func__);
+		return NULL;
+	}
+
+	/* Initialization */
+	port->kni = conf->kni;
+	port->tx_burst_sz = conf->tx_burst_sz;
+	port->tx_buf_count = 0;
+	port->bsz_mask = 1LLU << (conf->tx_burst_sz - 1);
+
+	/*
+	 * When n_retries is 0 it means that we should wait for every packet to
+	 * send no matter how many retries should it take. To limit number of
+	 * branches in fast path, we use UINT64_MAX instead of branching.
+	 */
+	port->n_retries = (conf->n_retries == 0) ? UINT64_MAX : conf->n_retries;
+
+	return port;
+}
+
+static inline void
+send_burst_nodrop(struct rte_port_kni_writer_nodrop *p)
+{
+	uint32_t nb_tx = 0, i;
+
+	nb_tx = rte_kni_tx_burst(p->kni, p->tx_buf, p->tx_buf_count);
+
+	/* We sent all the packets in a first try */
+	if (nb_tx >= p->tx_buf_count) {
+		p->tx_buf_count = 0;
+		return;
+	}
+
+	for (i = 0; i < p->n_retries; i++) {
+		nb_tx += rte_kni_tx_burst(p->kni,
+			p->tx_buf + nb_tx,
+			p->tx_buf_count - nb_tx);
+
+		/* We sent all the packets in more than one try */
+		if (nb_tx >= p->tx_buf_count) {
+			p->tx_buf_count = 0;
+			return;
+		}
+	}
+
+	/* We didn't send the packets in maximum allowed attempts */
+	RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_DROP_ADD(p, p->tx_buf_count - nb_tx);
+	for ( ; nb_tx < p->tx_buf_count; nb_tx++)
+		rte_pktmbuf_free(p->tx_buf[nb_tx]);
+
+	p->tx_buf_count = 0;
+}
+
+static int
+rte_port_kni_writer_nodrop_tx(void *port, struct rte_mbuf *pkt)
+{
+	struct rte_port_kni_writer_nodrop *p =
+			(struct rte_port_kni_writer_nodrop *) port;
+
+	p->tx_buf[p->tx_buf_count++] = pkt;
+	RTE_PORT_KNI_WRITER_STATS_PKTS_IN_ADD(p, 1);
+	if (p->tx_buf_count >= p->tx_burst_sz)
+		send_burst_nodrop(p);
+
+	return 0;
+}
+
+static int
+rte_port_kni_writer_nodrop_tx_bulk(void *port,
+	struct rte_mbuf **pkts,
+	uint64_t pkts_mask)
+{
+	struct rte_port_kni_writer_nodrop *p =
+			(struct rte_port_kni_writer_nodrop *) port;
+
+	uint64_t bsz_mask = p->bsz_mask;
+	uint32_t tx_buf_count = p->tx_buf_count;
+	uint64_t expr = (pkts_mask & (pkts_mask + 1)) |
+					((pkts_mask & bsz_mask) ^ bsz_mask);
+
+	if (expr == 0) {
+		uint64_t n_pkts = __builtin_popcountll(pkts_mask);
+		uint32_t n_pkts_ok;
+
+		if (tx_buf_count)
+			send_burst_nodrop(p);
+
+		RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_IN_ADD(p, n_pkts);
+		n_pkts_ok = rte_kni_tx_burst(p->kni, pkts, n_pkts);
+
+		if (n_pkts_ok >= n_pkts)
+			return 0;
+
+		/*
+		 * If we didn't manage to send all packets in single burst, move
+		 * remaining packets to the buffer and call send burst.
+		 */
+		for (; n_pkts_ok < n_pkts; n_pkts_ok++) {
+			struct rte_mbuf *pkt = pkts[n_pkts_ok];
+			p->tx_buf[p->tx_buf_count++] = pkt;
+		}
+		send_burst_nodrop(p);
+	} else {
+		for ( ; pkts_mask; ) {
+			uint32_t pkt_index = __builtin_ctzll(pkts_mask);
+			uint64_t pkt_mask = 1LLU << pkt_index;
+			struct rte_mbuf *pkt = pkts[pkt_index];
+
+			p->tx_buf[tx_buf_count++] = pkt;
+			RTE_PORT_KNI_WRITER_NODROP_STATS_PKTS_IN_ADD(p, 1);
+			pkts_mask &= ~pkt_mask;
+		}
+
+		p->tx_buf_count = tx_buf_count;
+		if (tx_buf_count >= p->tx_burst_sz)
+			send_burst_nodrop(p);
+	}
+
+	return 0;
+}
+
+static int
+rte_port_kni_writer_nodrop_flush(void *port)
+{
+	struct rte_port_kni_writer_nodrop *p =
+		(struct rte_port_kni_writer_nodrop *) port;
+
+	if (p->tx_buf_count > 0)
+		send_burst_nodrop(p);
+
+	return 0;
+}
+
+static int
+rte_port_kni_writer_nodrop_free(void *port)
+{
+	if (port == NULL) {
+		RTE_LOG(ERR, PORT, "%s: Port is NULL\n", __func__);
+		return -EINVAL;
+	}
+
+	rte_port_kni_writer_nodrop_flush(port);
+	rte_free(port);
+
+	return 0;
+}
+
+static int rte_port_kni_writer_nodrop_stats_read(void *port,
+	struct rte_port_out_stats *stats, int clear)
+{
+	struct rte_port_kni_writer_nodrop *p =
+			(struct rte_port_kni_writer_nodrop *) port;
+
+	if (stats != NULL)
+		memcpy(stats, &p->stats, sizeof(p->stats));
+
+	if (clear)
+		memset(&p->stats, 0, sizeof(p->stats));
+
+	return 0;
+}
+
+
+/*
  * Summary of port operations
  */
 struct rte_port_in_ops rte_port_kni_reader_ops = {
@@ -323,3 +534,12 @@ struct rte_port_out_ops rte_port_kni_writer_ops = {
 	.f_flush = rte_port_kni_writer_flush,
 	.f_stats = rte_port_kni_writer_stats_read,
 };
+
+struct rte_port_out_ops rte_port_kni_writer_nodrop_ops = {
+	.f_create = rte_port_kni_writer_nodrop_create,
+	.f_free = rte_port_kni_writer_nodrop_free,
+	.f_tx = rte_port_kni_writer_nodrop_tx,
+	.f_tx_bulk = rte_port_kni_writer_nodrop_tx_bulk,
+	.f_flush = rte_port_kni_writer_nodrop_flush,
+	.f_stats = rte_port_kni_writer_nodrop_stats_read,
+};
diff --git a/lib/librte_port/rte_port_kni.h b/lib/librte_port/rte_port_kni.h
index d4de8c4..4b60689 100644
--- a/lib/librte_port/rte_port_kni.h
+++ b/lib/librte_port/rte_port_kni.h
@@ -75,6 +75,19 @@ struct rte_port_kni_writer_params {
 /** kni_writer port operations */
 extern struct rte_port_out_ops rte_port_kni_writer_ops;
 
+/** kni_writer_nodrop port parameters */
+struct rte_port_kni_writer_nodrop_params {
+	/** KNI interface reference */
+	struct rte_kni *kni;
+	/** Burst size to KNI interface. */
+	uint32_t tx_burst_sz;
+	/** Maximum number of retries, 0 for no limit */
+	uint32_t n_retries;
+};
+
+/** kni_writer_nodrop port operations */
+extern struct rte_port_out_ops rte_port_kni_writer_nodrop_ops;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_port/rte_port_version.map b/lib/librte_port/rte_port_version.map
index e61b3fa..c528658 100644
--- a/lib/librte_port/rte_port_version.map
+++ b/lib/librte_port/rte_port_version.map
@@ -41,5 +41,6 @@ DPDK_16.07 {
 
 	rte_port_kni_reader_ops;
 	rte_port_kni_writer_ops;
+	rte_port_kni_writer_nodrop_ops;
 
 } DPDK_2.2;
-- 
2.7.4