ixgbe_pmd has a minimum supported RX burst size of 4. If
less than 4 packets are requested with
odp_pktio_recv_queue(), rte_eth_rx_burst() is called with
nb_pkts=4 and the possibly received extra packets are cached
for the next dpdk_recv_queue() call to use.
Reviewed-by: Petri Savolainen <petri.savolai...@nokia.com>
Signed-off-by: Matias Elo <matias....@nokia.com>
---
platform/linux-generic/include/odp_packet_dpdk.h | 18 +++++++++
platform/linux-generic/pktio/dpdk.c | 47 ++++++++++++++++++++++--
2 files changed, 62 insertions(+), 3 deletions(-)
diff --git a/platform/linux-generic/include/odp_packet_dpdk.h
b/platform/linux-generic/include/odp_packet_dpdk.h
index 3244175..d1e152f 100644
--- a/platform/linux-generic/include/odp_packet_dpdk.h
+++ b/platform/linux-generic/include/odp_packet_dpdk.h
@@ -30,6 +30,21 @@ _ODP_STATIC_ASSERT(DPDK_NB_MBUF % DPDK_MEMPOOL_CACHE_SIZE ==
0 &&
, "DPDK mempool cache size failure");
#endif
+#define DPDK_IXGBE_MIN_RX_BURST 4
+
+/** Cache for storing packets */
+struct pkt_cache_t {
+ /** array for storing extra RX packets */
+ struct rte_mbuf *pkt[DPDK_IXGBE_MIN_RX_BURST];
+ unsigned idx; /**< head of cache */
+ unsigned count; /**< packets in cache */
+};
+
+typedef union {
+ struct pkt_cache_t s;
+ uint8_t pad[ODP_CACHE_LINE_SIZE_ROUNDUP(sizeof(struct pkt_cache_t))];
+} pkt_cache_t ODP_ALIGNED_CACHE;
+
/** Packet IO using DPDK interface */
typedef struct {
odp_pool_t pool; /**< pool to alloc packets from */
@@ -40,11 +55,14 @@ typedef struct {
/** DPDK packet pool name (pktpool_<ifname>) */
char pool_name[IF_NAMESIZE + 8];
uint8_t port_id; /**< DPDK port identifier */
+ unsigned min_rx_burst; /**< minimum RX burst size */
odp_pktin_hash_proto_t hash; /**< Packet input hash protocol */
odp_bool_t lockless_rx; /**< no locking for rx */
odp_bool_t lockless_tx; /**< no locking for tx */
odp_ticketlock_t rx_lock[PKTIO_MAX_QUEUES]; /**< RX queue locks */
odp_ticketlock_t tx_lock[PKTIO_MAX_QUEUES]; /**< TX queue locks */
+ /** cache for storing extra RX packets */
+ pkt_cache_t rx_cache[PKTIO_MAX_QUEUES];
} pkt_dpdk_t;
#endif
diff --git a/platform/linux-generic/pktio/dpdk.c
b/platform/linux-generic/pktio/dpdk.c
index 10600db..d35896e 100644
--- a/platform/linux-generic/pktio/dpdk.c
+++ b/platform/linux-generic/pktio/dpdk.c
@@ -423,6 +423,11 @@ static int dpdk_open(odp_pktio_t id ODP_UNUSED,
}
pkt_dpdk->mtu = mtu;
+ if (!strcmp(dev_info.driver_name, "rte_ixgbe_pmd"))
+ pkt_dpdk->min_rx_burst = DPDK_IXGBE_MIN_RX_BURST;
+ else
+ pkt_dpdk->min_rx_burst = 0;
+
/* Look for previously opened packet pool */
pkt_pool = rte_mempool_lookup(pkt_dpdk->pool_name);
if (pkt_pool == NULL)
@@ -615,15 +620,51 @@ static int dpdk_recv_queue(pktio_entry_t *pktio_entry,
int num)
{
pkt_dpdk_t *pkt_dpdk = &pktio_entry->s.pkt_dpdk;
+ pkt_cache_t *rx_cache = &pkt_dpdk->rx_cache[index];
uint16_t nb_rx;
-
struct rte_mbuf *rx_mbufs[num];
+ int i;
+ unsigned cache_idx;
if (!pkt_dpdk->lockless_rx)
odp_ticketlock_lock(&pkt_dpdk->rx_lock[index]);
+ /**
+ * ixgbe_pmd has a minimum supported RX burst size ('min_rx_burst'). If
+ * 'num' < 'min_rx_burst', 'min_rx_burst' is used as rte_eth_rx_burst()
+ * argument and the possibly received extra packets are cached for the
+ * next dpdk_recv_queue() call to use.
+ *
+ * Either use cached packets or receive new ones. Not both during the
+ * same call. */
+ if (rx_cache->s.count > 0) {
+ for (i = 0; i < num && rx_cache->s.count; i++) {
+ rx_mbufs[i] = rx_cache->s.pkt[rx_cache->s.idx];
+ rx_cache->s.idx++;
+ rx_cache->s.count--;
+ }
+ nb_rx = i;
+ } else if ((unsigned)num < pkt_dpdk->min_rx_burst) {
+ struct rte_mbuf *new_mbufs[pkt_dpdk->min_rx_burst];
- nb_rx = rte_eth_rx_burst(pktio_entry->s.pkt_dpdk.port_id, index,
- rx_mbufs, num);
+ nb_rx = rte_eth_rx_burst(pktio_entry->s.pkt_dpdk.port_id, index,
+ new_mbufs, pkt_dpdk->min_rx_burst);
+
+ rx_cache->s.idx = 0;
+ for (i = 0; i < nb_rx; i++) {
+ if (i < num) {
+ rx_mbufs[i] = new_mbufs[i];
+ } else {
+ cache_idx = rx_cache->s.count;
+ rx_cache->s.pkt[cache_idx] = new_mbufs[i];
+ rx_cache->s.count++;
+ }
+ }
+ nb_rx = RTE_MIN(num, nb_rx);
+
+ } else {
+ nb_rx = rte_eth_rx_burst(pktio_entry->s.pkt_dpdk.port_id, index,
+ rx_mbufs, num);
+ }
if (nb_rx > 0)
nb_rx = mbuf_to_pkt(pktio_entry, pkt_table, rx_mbufs, nb_rx);
--
1.9.1
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