add overflow_egress for PGDropTest multi-asic (#9464)

Signed-off-by: Zhixin Zhu <zhixzhu@cisco.com>

tests/qos/test_qos_sai.py

@@ -1535,21 +1535,13 @@ def testQosSaiPGDrop(
 
         testParams = dict()
         testParams.update(dutTestParams["basicParams"])
-        pgDropKey = "pg_drop"
+        testParams.update(qosConfig['pg_drop'])
         testParams.update({
-            "dscp": qosConfig[pgDropKey]["dscp"],
-            "ecn": qosConfig[pgDropKey]["ecn"],
-            "pg": qosConfig[pgDropKey]["pg"],
-            "queue": qosConfig[pgDropKey]["queue"],
             "dst_port_id": dutConfig["testPorts"]["dst_port_id"],
             "dst_port_ip": dutConfig["testPorts"]["dst_port_ip"],
             "src_port_id": dutConfig["testPorts"]["src_port_id"],
             "src_port_ip": dutConfig["testPorts"]["src_port_ip"],
             "src_port_vlan": dutConfig["testPorts"]["src_port_vlan"],
-            "pkts_num_trig_pfc": qosConfig[pgDropKey]["pkts_num_trig_pfc"],
-            "pkts_num_trig_ingr_drp": qosConfig[pgDropKey]["pkts_num_trig_ingr_drp"],
-            "pkts_num_margin": qosConfig[pgDropKey]["pkts_num_margin"],
-            "iterations": qosConfig[pgDropKey]["iterations"],
             "hwsku": dutTestParams['hwsku']
         })
 

tests/saitests/py3/sai_qos_tests.py

@@ -32,7 +32,8 @@
                     sai_thrift_read_pg_shared_watermark,
                     sai_thrift_read_buffer_pool_watermark,
                     sai_thrift_read_headroom_pool_watermark,
-                    sai_thrift_read_queue_occupancy)
+                    sai_thrift_read_queue_occupancy,
+                    sai_thrift_read_pg_occupancy)
 from switch_sai_thrift.ttypes import (sai_thrift_attribute_value_t,
                                       sai_thrift_attribute_t)
 from switch_sai_thrift.sai_headers import (SAI_PORT_ATTR_QOS_SCHEDULER_PROFILE_ID)
@@ -241,6 +242,37 @@ def fill_leakout_plus_one(test_case, src_port_id, dst_port_id, pkt, queue, asic_
     return False
 
 
+def overflow_egress(test_case, src_port_id, pkt, queue, asic_type):
+    # Attempts to queue 1 packet while compensating for a varying packet
+    # leakout and egress queues. Returns pkts_num_egr_mem: number of packets
+    # short of filling egress memory and leakout.
+    # Returns extra_bytes_occupied:
+    #    extra number of bytes occupied in source port
+    pkts_num_egr_mem = 0
+    extra_bytes_occupied = 0
+    if asic_type not in ['cisco-8000']:
+        return pkts_num_egr_mem, extra_bytes_occupied
+
+    pg_cntrs_base = sai_thrift_read_pg_occupancy(
+        test_case.src_client, port_list['src'][src_port_id])
+    max_cycles = 1000
+    for cycle_i in range(max_cycles):
+        send_packet(test_case, src_port_id, pkt, 1000)
+        pg_cntrs = sai_thrift_read_pg_occupancy(
+            test_case.src_client, port_list['src'][src_port_id])
+        if pg_cntrs[queue] > pg_cntrs_base[queue]:
+            print("get_pkts_num_egr_mem: Success, sent %d packets, "
+                  "SQ occupancy bytes rose from %d to %d" % (
+                      (cycle_i + 1) * 1000, pg_cntrs_base[queue],
+                      pg_cntrs[queue]), file=sys.stderr)
+            pkts_num_egr_mem = cycle_i * 1000
+            extra_bytes_occupied = pg_cntrs[queue] - pg_cntrs_base[queue]
+            print("overflow_egress:pkts_num_egr_mem:{}, extra_bytes_occupied:{}".format(
+                pkts_num_egr_mem, extra_bytes_occupied))
+            return pkts_num_egr_mem, extra_bytes_occupied
+    raise RuntimeError("Couldn't overflow the egress memory after 1000 iterations.")
+
+
 def get_peer_addresses(data):
     def get_peer_addr(data, addr):
         if isinstance(data, dict) and 'peer_addr' in data:
@@ -3865,6 +3897,8 @@ def runTest(self):
             self.test_params['pkts_num_trig_ingr_drp'])
         iterations = int(self.test_params['iterations'])
         margin = int(self.test_params['pkts_num_margin'])
+        cell_size = int(self.test_params.get('cell_size', 0))
+        is_multi_asic = (self.src_client != self.dst_client)
 
         pkt_dst_mac = router_mac if router_mac != '' else dst_port_mac
         dst_port_id = get_rx_port(
@@ -3896,14 +3930,21 @@ def runTest(self):
 
                 pg_dropped_cntrs_base = sai_thrift_read_pg_drop_counters(
                     self.src_client, port_list['src'][src_port_id])
+                pkt_num = pkts_num_trig_pfc
+
+                # Fill egress memory and leakout
+                if 'cisco-8000' in asic_type and is_multi_asic:
+                    pkts_num_egr_mem, extra_bytes_occupied = overflow_egress(
+                        self, src_port_id, pkt, pg, asic_type)
+                    pkt_num -= extra_bytes_occupied // cell_size
 
                 # Send packets to trigger PFC
                 print("Iteration {}/{}, sending {} packets to trigger PFC".format(
                     test_i + 1, iterations, pkts_num_trig_pfc), file=sys.stderr)
-                send_packet(self, src_port_id, pkt, pkts_num_trig_pfc)
+                send_packet(self, src_port_id, pkt, pkt_num)
 
                 # Account for leakout
-                if 'cisco-8000' in asic_type:
+                if 'cisco-8000' in asic_type and not is_multi_asic:
                     queue_counters = sai_thrift_read_queue_occupancy(
                         self.dst_client, "dst", dst_port_id)
                     occ_pkts = queue_counters[queue] // (packet_length + 24)