Re: [dpdk-dev] [PATCH v5 10/11] net/octeontx_ep: receive data path function added

On 1/28/2021 3:22 PM, Nalla Pradeep wrote:

Function to deliver packets from DROQ to application is added. It also
fills DROQ with receive buffers timely such that device can fill them
with incoming packets.

Signed-off-by: Nalla Pradeep <redacted>

<...>

+/* Check for response arrival from OCTEON TX2
+ * returns number of requests completed
+ */
+uint16_t
+otx_ep_recv_pkts(void *rx_queue,
+		  struct rte_mbuf **rx_pkts,
+		  uint16_t budget)
+{
+	struct otx_ep_droq *droq = rx_queue;
+	struct otx_ep_device *otx_ep;
+	struct rte_mbuf *oq_pkt;
+
+	uint32_t pkts = 0;
+	uint32_t new_pkts = 0;
+	int next_fetch;
+
+	otx_ep = droq->otx_ep_dev;
+
+	if (droq->pkts_pending > budget) {
+		new_pkts = budget;
+	} else {
+		new_pkts = droq->pkts_pending;
+		new_pkts += otx_ep_check_droq_pkts(droq);
+		if (new_pkts > budget)
+			new_pkts = budget;
+	}
+
+	if (!new_pkts)
+		goto update_credit; /* No pkts at this moment */
+
+	for (pkts = 0; pkts < new_pkts; pkts++) {
+		/* Push the received pkt to application */
+		next_fetch = (pkts == new_pkts - 1) ? 0 : 1;
+		oq_pkt = otx_ep_droq_read_packet(otx_ep, droq, next_fetch);
+		if (!oq_pkt) {
+			otx_ep_err("DROQ read pkt failed pending %" PRIu64
+				    "last_pkt_count %" PRIu64 "new_pkts %d.\n",
+				    droq->pkts_pending, droq->last_pkt_count,
+				    new_pkts);

The format specifier seems fixed, but in a second thought, are you sure that you 
want to add logging into a fast path?
Even if it doesn't log anything it will consume cycles, and if it logs it will 
impact the datapath a lot.

There is a 'RTE_LOG_DP' macro for datapath, you may consider using it.