update version to 26.02.1 and fix PCAP rate calculation to use average packet size

Signed-off-by: Keith Wiles <keith.wiles@intel.com>

Author: KeithWiles

VERSION

@@ -1 +1 @@
-26.02.0
+26.02.1

app/pktgen-pcap.c

@@ -82,7 +82,9 @@ pcap_get_info(pcap_info_t *pcap)
         pcap->info.network       = ntohl(pcap->info.network);
     }
 
-    pcap->max_pkt_size = 0;
+    pcap->max_pkt_size  = 0;
+    pcap->avg_pkt_size  = 0;
+    uint64_t total_size = 0;
     /* count the number of packets and get the largest size packet */
     for (;;) {
         if (fread(&hdr, 1, sizeof(pcap_record_hdr_t), pcap->fp) != sizeof(hdr))
@@ -97,9 +99,15 @@ pcap_get_info(pcap_info_t *pcap)
         pcap->pkt_count++;
         if (hdr.incl_len > pcap->max_pkt_size)
             pcap->max_pkt_size = hdr.incl_len;
+
+        total_size += hdr.incl_len;
     }
     printf("PCAP: Max Packet Size: %d\n", pcap->max_pkt_size);
 
+    pcap->avg_pkt_size = total_size / pcap->pkt_count;
+
+    printf("PCAP: Avg Packet Size: %d\n", pcap->avg_pkt_size);
+
     pcap_rewind(pcap);
 }
 

app/pktgen-pcap.h

@@ -41,6 +41,7 @@ typedef struct pcap_info_s {
     struct rte_mempool *mp;          /**< Mempool for storing packets */
     uint32_t convert;                /**< Endian flag value if 1 convert to host endian format */
     uint32_t max_pkt_size;           /**< largest packet found in pcap file */
+    uint32_t avg_pkt_size;           /**< average packet size in pcap file */
     uint32_t pkt_count;              /**< Number of packets in pcap file */
     uint32_t pkt_index;              /**< Index of current packet in pcap file */
     pcap_hdr_t info;                 /**< information on the PCAP file */

app/pktgen.c

@@ -64,7 +64,7 @@ pktgen_wire_size(port_info_t *pinfo)
     if (pktgen_tst_port_flags(pinfo, SEND_PCAP_PKTS)) {
         pcap_info_t *pcap = l2p_get_pcap(pinfo->pid);
 
-        size = WIRE_SIZE(pcap->max_pkt_size, uint64_t);
+        size = WIRE_SIZE(pcap->avg_pkt_size, uint64_t);
     } else {
         if (unlikely(pinfo->seqCnt > 0)) {
             for (i = 0; i < pinfo->seqCnt; i++)
@@ -111,11 +111,10 @@ pktgen_packet_rate(port_info_t *port)
     pps = (((link_speed / pktgen_wire_size(port)) * (port->tx_rate / txcnt)) / 100);
     pps = ((pps > 0) ? pps : 1);
 
-    // cycles per burst is hz divided by pps times burst count
-    cpb = (rte_get_timer_hz() / pps) * (uint64_t)port->tx_burst; /* Cycles per Burst */
-
-    // divide up the work between the number of transmit queues, so multiple by queue count.
-    port->tx_cycles = cpb * (uint64_t)txcnt;
+    // Do all multiplications first to reduce rounding errors.
+    // Add pps/2 to do rounding instead of truncation.
+    cpb             = (pps / 2 + (uint64_t)txcnt * port->tx_burst * rte_get_timer_hz()) / pps;
+    port->tx_cycles = cpb;
     port->tx_pps    = pps;
 }
 
@@ -1070,9 +1069,11 @@ pktgen_main_rxtx_loop(void)
         curr_tsc = pktgen_get_time();
 
         /* Determine when is the next time to send packets */
-        if (curr_tsc >= tx_next_cycle) {
-            tx_next_cycle = curr_tsc + pinfo->tx_cycles;
-
+        const int64_t max_tx_lag =
+            DEFAULT_MAX_TX_LAG;        // Allow some lag, ideally make this configurable.
+        int64_t dt = curr_tsc - tx_next_cycle;
+        if (dt >= 0) {
+            tx_next_cycle = curr_tsc + pinfo->tx_cycles - (dt <= max_tx_lag ? dt : 0);
             // Process TX
             pktgen_main_transmit(pinfo, tx_qid);
         }
@@ -1124,8 +1125,11 @@ pktgen_main_tx_loop(void)
         curr_tsc = pktgen_get_time();
 
         /* Determine when is the next time to send packets */
-        if (unlikely(curr_tsc >= tx_next_cycle)) {
-            tx_next_cycle = curr_tsc + pinfo->tx_cycles;
+        const int64_t max_tx_lag =
+            DEFAULT_MAX_TX_LAG;        // Allow some lag, ideally make this configurable.
+        int64_t dt = curr_tsc - tx_next_cycle;
+        if (dt >= 0) {
+            tx_next_cycle = curr_tsc + pinfo->tx_cycles - (dt <= max_tx_lag ? dt : 0);
 
             // Process TX
             pktgen_main_transmit(pinfo, tx_qid);

app/pktgen.h

@@ -167,6 +167,8 @@ enum {
     COLUMN_WIDTH_1 = 24,
     COLUMN_WIDTH_3 = 24,
 
+    DEFAULT_MAX_TX_LAG = 20000, /* Allow some lag, ideally make this configurable. */
+
     /* Row locations for start of data */
     PAGE_TITLE_ROWS = 1,
     PORT_FLAGS_ROWS = 1,

changelog.txt

@@ -6,7 +6,8 @@ Pktgen-DPDK - Traffic Generator powered by DPDK
 ** (Pktgen) Sounds like 'Packet-Gen'**
 
 **=== Modifications ===**
- - 26.02.3 - Add better cli-autocomplete support
+ - 26.02.1 - Fix PCAP rate issues not using the average size packet.
+ - 26.02.0 - Add better cli-autocomplete support
  - 25.08.2 - Fix race condition in CLI.
  - 25.08.1 - Fix DPDK 25.11 ethdev queue changes
              Fix running multiple Tx queues and stats are reported incorrectly.