Parametrize T-Rex rx/tx descriptors count

Additional configuration can provide performance boosts when running in virtual environments
If set to 0, uses default DPDK value
By tuning this value it's also possible to run T-Rex 2.88 with ENA NICs on AWS

Signed-off-by: Tomas Alexy <tomas.alexy@pantheon.tech>
Change-Id: I43c86ea1d9aa854a1087f07fe544ac77a5b80397

1 files changed, 18 insertions, 0 deletions

diff --git a/resources/libraries/python/TrafficGenerator.py b/resources/libraries/python/TrafficGenerator.py
index 9a9519e248..c0d1b4ec63 100644
--- a/resources/libraries/python/TrafficGenerator.py
+++ b/resources/libraries/python/TrafficGenerator.py
@@ -343,6 +343,24 @@ class TrafficGenerator(AbstractMeasurer):
                     f"EOF'",
                     sudo=True, message=u"T-Rex config generation!"
                 )
+
+                if Constants.TREX_RX_DESCRIPTORS_COUNT != 0:
+                    exec_cmd_no_error(
+                        self._node,
+                        f"sh -c 'cat << EOF >> /etc/trex_cfg.yaml\n"
+                        f"  rx_desc: {Constants.TREX_RX_DESCRIPTORS_COUNT}\n"
+                        f"EOF'",
+                        sudo=True, message=u"T-Rex rx_desc modification!"
+                    )
+
+                if Constants.TREX_TX_DESCRIPTORS_COUNT != 0:
+                    exec_cmd_no_error(
+                        self._node,
+                        f"sh -c 'cat << EOF >> /etc/trex_cfg.yaml\n"
+                        f"  tx_desc: {Constants.TREX_TX_DESCRIPTORS_COUNT}\n"
+                        f"EOF'",
+                        sudo=True, message=u"T-Rex tx_desc modification!"
+                    )
             else:
                 raise ValueError(u"Unknown OSI layer!")