Skip only lossless PGs when cable length is 0m

Changes:
- Add lossless check in cable length handling
- Only skip PG creation when both cable length is 0m AND PG is lossless
- Allow lossy PGs to be created regardless of cable length

Test:
- Add unit test to verify lossy PG can be created with 0m cable length
- Verify lossy PG profile and attributes are set correctly

Signed-off-by: Jianyue Wu <jianyuew@nvidia.com>

Author: jianyuewu

cfgmgr/buffermgrdyn.cpp

@@ -944,7 +944,8 @@ void BufferMgrDynamic::updateBufferObjectListToDb(const string &key, const strin
 // We have to check the headroom ahead of applying them
 task_process_status BufferMgrDynamic::allocateProfile(const string &speed, const string &cable_len, const string &mtu, const string &threshold, const string &gearbox_model, long lane_count, string &profile_name)
 {
-    if (cable_len == "0m")
+    bool is_lossless = (profile_name.find("pg_lossless_") != string::npos);
+    if (cable_len == "0m" && is_lossless)
     {
         SWSS_LOG_NOTICE("Not creating PG profile when cable length is set to %s", cable_len.c_str());
         return task_process_status::task_success;
@@ -1468,7 +1469,7 @@ task_process_status BufferMgrDynamic::refreshPgsForPort(const string &port, cons
                 continue;
             }
 
-            if (cable_length == "0m")
+            if (cable_length == "0m" && it->second.lossless)
             {
                 updateBufferObjectToDb(key, oldProfile, false); // 0m, remove PG.
                 SWSS_LOG_NOTICE("All profiles for port %s have been removed due to cable length being set to '0m'", port.c_str());

tests/mock_tests/buffermgrdyn_ut.cpp

@@ -137,6 +137,11 @@ namespace buffermgrdyn_test
                 {"size", "1024000"}
             };
 
+            testBufferProfile["ingress_lossy_profile"] = {
+                {"dynamic_th", "7"},
+                {"pool", "ingress_lossless_pool"},
+                {"size", "0"}
+            };
             testBufferProfile["ingress_lossless_profile"] = {
                 {"dynamic_th", "7"},
                 {"pool", "ingress_lossless_pool"},
@@ -522,8 +527,8 @@ namespace buffermgrdyn_test
 
         InitDefaultBufferProfile();
         appBufferProfileTable.getKeys(keys);
-        ASSERT_EQ(keys.size(), 3);
-        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+        ASSERT_EQ(keys.size(), 4);
+        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 4);
         for (auto i : testBufferProfile)
         {
             CheckProfile(m_dynamicBuffer->m_bufferProfileLookup[i.first], testBufferProfile[i.first]);
@@ -647,7 +652,7 @@ namespace buffermgrdyn_test
         appBufferPoolTable.getKeys(keys);
         ASSERT_EQ(keys.size(), 3);
         ASSERT_EQ(m_dynamicBuffer->m_bufferPoolLookup.size(), 3);
-        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 4);
         for (auto i : testBufferProfile)
         {
             CheckProfile(m_dynamicBuffer->m_bufferProfileLookup[i.first], testBufferProfile[i.first]);
@@ -933,8 +938,8 @@ namespace buffermgrdyn_test
 
             InitDefaultBufferProfile();
             appBufferProfileTable.getKeys(keys);
-            ASSERT_EQ(keys.size(), 3);
-            ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+            ASSERT_EQ(keys.size(), 4);
+            ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 4);
             for (auto i : testBufferProfile)
             {
                 CheckProfile(m_dynamicBuffer->m_bufferProfileLookup[i.first], testBufferProfile[i.first]);
@@ -1267,8 +1272,8 @@ namespace buffermgrdyn_test
         ASSERT_EQ(keys.size(), 3);
         InitDefaultBufferProfile();
         appBufferProfileTable.getKeys(keys);
-        ASSERT_EQ(keys.size(), 3);
-        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+        ASSERT_EQ(keys.size(), 4);
+        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 4);
 
         m_dynamicBuffer->m_bufferCompletelyInitialized = true;
         m_dynamicBuffer->m_waitApplyAdditionalZeroProfiles = 0;
@@ -1499,8 +1504,8 @@ namespace buffermgrdyn_test
         InitBufferPg("Ethernet0|3-4");
         InitDefaultBufferProfile();
         appBufferProfileTable.getKeys(keys);
-        ASSERT_EQ(keys.size(), 3);
-        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 3);
+        ASSERT_EQ(keys.size(), 4);
+        ASSERT_EQ(m_dynamicBuffer->m_bufferProfileLookup.size(), 4);
 
         // 1. Set cable length to "0m"
         InitCableLength("Ethernet0", "0m");
@@ -1526,6 +1531,7 @@ namespace buffermgrdyn_test
 
         // 5. Update cable length to 0m, then Ethernet0:6 should be deleted, Ethernet0:3-4 should be deleted and 0m profile also not exist, and 5m profile should be deleted, PG also deleted, as profiles not exist
         InitCableLength("Ethernet0", "0m");
+        static_cast<Orch *>(m_dynamicBuffer)->doTask();
         // Check that the profiles for 0m and 5m both do not exist
         ASSERT_TRUE(m_dynamicBuffer->m_bufferProfileLookup.find("pg_lossless_100000_0m_profile") == m_dynamicBuffer->m_bufferProfileLookup.end());
         ASSERT_TRUE(m_dynamicBuffer->m_bufferProfileLookup.find("pg_lossless_100000_5m_profile") == m_dynamicBuffer->m_bufferProfileLookup.end());
@@ -1537,8 +1543,19 @@ namespace buffermgrdyn_test
         InitCableLength("Ethernet0", "5m");
         string mtu = "4096";
         m_dynamicBuffer->m_portInfoLookup["Ethernet0"].mtu = mtu;
+        static_cast<Orch *>(m_dynamicBuffer)->doTask();
         // Check if the profile is created correctly
         CheckPg("Ethernet0", "Ethernet0:3-4", "pg_lossless_100000_5m_profile");
         CheckPg("Ethernet0", "Ethernet0:6", "pg_lossless_100000_5m_profile");
+
+        // 7. Check if lossy PG can still be created
+        InitBufferPg("Ethernet0|0", "ingress_lossy_profile");
+        InitCableLength("Ethernet0", "0m");
+        bool found = false;
+        auto it = m_dynamicBuffer->m_portPgLookup.find("Ethernet0");
+        if (it != m_dynamicBuffer->m_portPgLookup.end()) {
+            found = (it->second.find("Ethernet0:0") != it->second.end());
+        }
+        ASSERT_TRUE(found);
     }
 }