[202411] Restore disable packet aging fixture 202411 (sonic-net#18103)

* Restore fixture disable_packet_aging

Author: bingwang-ms

tests/qos/test_tunnel_qos_remap.py

@@ -29,7 +29,7 @@
     dut_config, qos_config, tunnel_qos_maps, run_ptf_test, toggle_mux_to_host,\
     setup_module, update_docker_services, swap_syncd, counter_poll_config                               # noqa F401
 from .tunnel_qos_remap_base import leaf_fanout_peer_info, start_pfc_storm, \
-    stop_pfc_storm, get_queue_counter, get_queue_watermark                                              # noqa F401
+    stop_pfc_storm, get_queue_counter, get_queue_watermark, disable_packet_aging                        # noqa F401
 from ptf import testutils
 from ptf.testutils import simple_tcp_packet
 from tests.common.fixtures.conn_graph_facts import conn_graph_facts, fanout_graph_facts     # noqa F401

tests/qos/tunnel_qos_remap_base.py

@@ -316,6 +316,32 @@ def qos_config(rand_selected_dut, tbinfo, dut_config):
     return speed_cable_to_params[speed_cable]
 
 
+@pytest.fixture(scope='module', autouse=True)
+def disable_packet_aging(duthosts):
+    """
+        For Nvidia(Mellanox) platforms, packets in buffer will be aged after a timeout. Need to disable this
+        before any buffer tests.
+    """
+    for duthost in duthosts:
+        asic = duthost.get_asic_name()
+        if 'spc' in asic:
+            logger.info("Disable Mellanox packet aging")
+            duthost.copy(src="qos/files/mellanox/packets_aging.py", dest="/tmp")
+            duthost.command("docker cp /tmp/packets_aging.py syncd:/")
+            duthost.command("docker exec syncd python /packets_aging.py disable")
+
+    yield
+
+    for duthost in duthosts:
+        asic = duthost.get_asic_name()
+        if 'spc' in asic:
+            # Ignore errors if the script is not found in syncd container as it may be removed
+            # by swap_syncd
+            logger.info("Enable Mellanox packet aging")
+            duthost.command("docker exec syncd python /packets_aging.py enable", module_ignore_errors=True)
+            duthost.command("docker exec syncd rm -rf /packets_aging.py", module_ignore_errors=True)
+
+
 def _create_ssh_tunnel_to_syncd_rpc(duthost):
     dut_asic = duthost.asic_instance()
     dut_asic.create_ssh_tunnel_sai_rpc()