[pfcwd] Update PFC storm detection logic for Mellanox platforms (sonic-net#1586)

Use "PFC duration" counters in micro seconds instead of quanta

SONiC PFCWD logic requires "pfc duration" value in micro seconds but in
SAI it was provided as quanta of time. So it required additional conversion
which used speed value to do such conversion and it could cause PFCWD to
detect storm on operationally down port in case of link flapping.

Now there are new SAI attributes that provide "pfc duration" in micro
seconds so PCWD storm detection logic is updated in order to use this
new "pfc duration" counters. Such algorithm change helps to avoid false
PFC storm detection in case of link flapping because conversion is not
needed anymore.

Signed-off-by: Volodymyr Samotiy <[email protected]>

Author: volodymyrsamotiy

orchagent/orchdaemon.cpp

@@ -333,10 +333,48 @@ bool OrchDaemon::init()
         CFG_PFC_WD_TABLE_NAME
     };
 
-    if ((platform == MLNX_PLATFORM_SUBSTRING)
-        || (platform == INVM_PLATFORM_SUBSTRING)
-        || (platform == BFN_PLATFORM_SUBSTRING)
-        || (platform == NPS_PLATFORM_SUBSTRING))
+    if (platform == MLNX_PLATFORM_SUBSTRING)
+    {
+
+        static const vector<sai_port_stat_t> portStatIds =
+        {
+            SAI_PORT_STAT_PFC_0_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_1_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_2_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_3_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_4_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_5_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_6_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_7_RX_PAUSE_DURATION_US,
+            SAI_PORT_STAT_PFC_0_RX_PKTS,
+            SAI_PORT_STAT_PFC_1_RX_PKTS,
+            SAI_PORT_STAT_PFC_2_RX_PKTS,
+            SAI_PORT_STAT_PFC_3_RX_PKTS,
+            SAI_PORT_STAT_PFC_4_RX_PKTS,
+            SAI_PORT_STAT_PFC_5_RX_PKTS,
+            SAI_PORT_STAT_PFC_6_RX_PKTS,
+            SAI_PORT_STAT_PFC_7_RX_PKTS,
+        };
+
+        static const vector<sai_queue_stat_t> queueStatIds =
+        {
+            SAI_QUEUE_STAT_PACKETS,
+            SAI_QUEUE_STAT_CURR_OCCUPANCY_BYTES,
+        };
+
+        static const vector<sai_queue_attr_t> queueAttrIds;
+
+        m_orchList.push_back(new PfcWdSwOrch<PfcWdZeroBufferHandler, PfcWdLossyHandler>(
+                    m_configDb,
+                    pfc_wd_tables,
+                    portStatIds,
+                    queueStatIds,
+                    queueAttrIds,
+                    PFC_WD_POLL_MSECS));
+    }
+    else if ((platform == INVM_PLATFORM_SUBSTRING)
+             || (platform == BFN_PLATFORM_SUBSTRING)
+             || (platform == NPS_PLATFORM_SUBSTRING))
     {
 
         static const vector<sai_port_stat_t> portStatIds =
@@ -367,9 +405,7 @@ bool OrchDaemon::init()
 
         static const vector<sai_queue_attr_t> queueAttrIds;
 
-        if ((platform == MLNX_PLATFORM_SUBSTRING)
-            || (platform == INVM_PLATFORM_SUBSTRING)
-            || (platform == NPS_PLATFORM_SUBSTRING))
+        if ((platform == INVM_PLATFORM_SUBSTRING) || (platform == NPS_PLATFORM_SUBSTRING))
         {
             m_orchList.push_back(new PfcWdSwOrch<PfcWdZeroBufferHandler, PfcWdLossyHandler>(
                         m_configDb,

orchagent/pfc_detect_mellanox.lua

@@ -8,26 +8,10 @@ local counters_db = ARGV[1]
 local counters_table_name = ARGV[2]
 local poll_time = tonumber(ARGV[3])
 
-local asic_db = "1"
-local asic_db_port_table = "ASIC_STATE:SAI_OBJECT_TYPE_PORT"
-
-local quanta_size = 512
-
 local rets = {}
 
 redis.call('SELECT', counters_db)
 
-local function port_speed_get(port_id)
-    redis.call('SELECT', asic_db)
-    local port_speed = redis.call('HGET', asic_db_port_table .. ':' .. port_id, 'SAI_PORT_ATTR_SPEED')
-    redis.call('SELECT', counters_db)
-    return tonumber(port_speed)
-end
-
-local function quantatous(quanta, port_id)
-    return quanta * quanta_size / port_speed_get(port_id)
-end
-
 -- Iterate through each queue
 local n = table.getn(KEYS)
 for i = n, 1, -1 do
@@ -53,7 +37,7 @@ for i = n, 1, -1 do
             local queue_index = redis.call('HGET', 'COUNTERS_QUEUE_INDEX_MAP', KEYS[i])
             local port_id = redis.call('HGET', 'COUNTERS_QUEUE_PORT_MAP', KEYS[i])
             local pfc_rx_pkt_key = 'SAI_PORT_STAT_PFC_' .. queue_index .. '_RX_PKTS'
-            local pfc_duration_key = 'SAI_PORT_STAT_PFC_' .. queue_index .. '_RX_PAUSE_DURATION'
+            local pfc_duration_key = 'SAI_PORT_STAT_PFC_' .. queue_index .. '_RX_PAUSE_DURATION_US'
 
             -- Get all counters
             local occupancy_bytes = redis.call('HGET', counters_table_name .. ':' .. KEYS[i], 'SAI_QUEUE_STAT_CURR_OCCUPANCY_BYTES')
@@ -79,7 +63,7 @@ for i = n, 1, -1 do
                     packets_last = tonumber(packets_last)
                     pfc_rx_packets_last = tonumber(pfc_rx_packets_last)
                     pfc_duration_last = tonumber(pfc_duration_last)
-                    local storm_condition = ((quantatous(pfc_duration, port_id) - quantatous(pfc_duration_last, port_id)) > poll_time * 0.8)
+                    local storm_condition = (pfc_duration - pfc_duration_last) > (poll_time * 0.8)
 
                     -- Check actual condition of queue being in PFC storm
                     if (occupancy_bytes > 0 and packets - packets_last == 0 and pfc_rx_packets - pfc_rx_packets_last > 0) or