Normal kernels always use IBGDA mode.

csrc/kernels/runtime.cu

@@ -58,15 +58,12 @@ int init(const std::vector<uint8_t> &root_unique_id_val, int rank, int num_ranks
         EP_HOST_ASSERT(cpu_rdma_team != NVSHMEM_TEAM_INVALID);
     }
 
-    // Normal operations use IBRC, while low-latency operations use IBGDA
-    bool internode_use_ibgda = true;
-    if (low_latency_mode or internode_use_ibgda) {
+    // TODO: we still use `nvshmem_barrier` under IBRC mode, which should be switch to IBGDA mode later
     nvshmemi_device_host_state_t* dev_state_ptr = nullptr;
     CUDA_CHECK(cudaGetSymbolAddress(reinterpret_cast<void**>(&dev_state_ptr), nvshmemi_device_state_d));
 
     bool ibgda_is_initialized = false;
     CUDA_CHECK(cudaMemcpy(&dev_state_ptr->ibgda_is_initialized, &ibgda_is_initialized, sizeof(bool), cudaMemcpyHostToDevice));
-    }
     nvshmem_barrier_all();
     return nvshmem_my_pe();
 }

deep_ep/buffer.py

@@ -65,10 +65,8 @@ class Buffer:
 
         # Synchronize NVSHMEM unique IDs
         root_unique_id = None
-        internode_use_ibgda = True
         if self.runtime.get_num_rdma_ranks() > 1 or low_latency_mode:
-            # Enable IBGDA for the low latency mode, which refers to "no package forwarding between NVLink and RDMA"
-            if low_latency_mode or internode_use_ibgda:
+            # Enable IBGDA 
             assert num_qps_per_rank > 0
             os.environ['NVSHMEM_DISABLE_P2P'] = '1'
             os.environ['NVSHMEM_IB_ENABLE_IBGDA'] = '1'