Merge pull request #130 from deepseek-ai/trmt/internode_multi_qp

Support multi-QP for normal kernels

README.md

@@ -18,8 +18,10 @@ We test normal kernels on H800 (~160 GB/s NVLink maximum bandwidth), with each c
 |:---------:|:------------:|:--------------------:|:-----------:|:--------------------:|
 | Intranode |      8       |  153 GB/s (NVLink)   |      8      |  158 GB/s (NVLink)   |
 | Internode |      16      |    43 GB/s (RDMA)    |     16      |    43 GB/s (RDMA)    |
-| Internode |      32      |    44 GB/s (RDMA)    |     32      |    47 GB/s (RDMA)    |
-| Internode |      64      |    46 GB/s (RDMA)    |     64      |    45 GB/s (RDMA)    |
+| Internode |      32      |    58 GB/s (RDMA)    |     32      |    57 GB/s (RDMA)    |
+| Internode |      64      |    51 GB/s (RDMA)    |     64      |    50 GB/s (RDMA)    |
+
+**News (2025.04.22)**: with optimizations from Tencent Network Platform Department, performance was enhanced by up to 30%, see [#130](https://github.com/deepseek-ai/DeepEP/pull/130) for more details. Thanks for the contribution!
 
 ### Low-latency kernels with pure RDMA
 

csrc/kernels/ibgda_device.cuh

@@ -325,6 +325,7 @@ ibgda_write_empty_recv_wqe(void *out_wqe) {
     st_na_relaxed(reinterpret_cast<int4*>(data_seg_ptr), *reinterpret_cast<const int4*>(&data_seg));
 }
 
+template <bool kAlwaysDoPostSend = false>
 __device__ static __forceinline__ void
 nvshmemi_ibgda_put_nbi_warp(uint64_t req_rptr, uint64_t req_lptr, size_t bytes, int dst_pe, int qp_id, int lane_id, int message_idx) {
     // Get lkey and rkey, store them into lanes
@@ -365,7 +366,7 @@ nvshmemi_ibgda_put_nbi_warp(uint64_t req_rptr, uint64_t req_lptr, size_t bytes,
 
     // Submit
     if (lane_id == 0)
-        ibgda_submit_requests<false>(qp, base_wqe_idx, num_wqes, message_idx);
+        ibgda_submit_requests<kAlwaysDoPostSend>(qp, base_wqe_idx, num_wqes, message_idx);
     __syncwarp();
 }
 
@@ -410,7 +411,11 @@ __device__ static __forceinline__ void ibgda_write_amo_add_wqe(
     st_na_relaxed(reinterpret_cast<int4*>(data_seg_ptr), *reinterpret_cast<int4*>(&data_seg));
 }
 
-__device__ __forceinline__ void nvshmemi_ibgda_amo_nonfetch_add(void *rptr, const int& value, int pe, int qp_id) {
+__device__ __forceinline__ void nvshmemi_ibgda_amo_nonfetch_add(void *rptr, const int& value, int pe, int qp_id, bool is_local_copy = false) {
+    if (is_local_copy) {
+        // Fallback to NVSHMEM legacy API 
+        nvshmemx_signal_op(static_cast<uint64_t*>(rptr), value, NVSHMEM_SIGNAL_ADD, pe);
+    } else {
         nvshmemi_ibgda_device_qp_t *qp = ibgda_get_rc(pe, qp_id);
 
         __be32 rkey;
@@ -424,6 +429,7 @@ __device__ __forceinline__ void nvshmemi_ibgda_amo_nonfetch_add(void *rptr, cons
                                 qp->ibuf.lkey, raddr, rkey, my_wqe_idx, &wqe_ptrs);
 
         ibgda_submit_requests<true>(qp, my_wqe_idx, 1);
+    }
 }
 
 } // namespace deep_ep

csrc/kernels/internode.cu

@@ -3,6 +3,7 @@
 #include "exception.cuh"
 #include "launch.cuh"
 #include "utils.cuh"
+#include "ibgda_device.cuh"
 
 namespace deep_ep {
 
@@ -479,6 +480,8 @@ dispatch(int4* recv_x, float* recv_x_scales, int64_t* recv_topk_idx, float* recv
     const bool is_forwarder = sm_id % 2 == 0;
     const auto rdma_rank = rank / NUM_MAX_NVL_PEERS, nvl_rank = rank % NUM_MAX_NVL_PEERS;
 
+    EP_DEVICE_ASSERT(ibgda_get_state()->num_rc_per_pe >= num_channels);
+
     const auto role_meta = [=]() -> std::pair<WarpRole, int> {
         if (is_forwarder) {
             if (warp_id < NUM_MAX_NVL_PEERS) {
@@ -555,19 +558,27 @@ dispatch(int4* recv_x, float* recv_x_scales, int64_t* recv_topk_idx, float* recv
         // Send number of tokens in this channel by `-value - 1`
         EP_STATIC_ASSERT(NUM_MAX_NVL_PEERS * 2 + 2 <= 32, "Invalid number of NVL peers");
         for (int dst_rdma_rank = warp_id; dst_rdma_rank < kNumRDMARanks; dst_rdma_rank += kNumDispatchRDMASenderWarps) {
+            auto dst_ptr = dst_rdma_rank == rdma_rank ? rdma_channel_meta.recv_buffer(dst_rdma_rank) : rdma_channel_meta.send_buffer(dst_rdma_rank);
             if (lane_id < NUM_MAX_NVL_PEERS) {
-                rdma_channel_meta.send_buffer(dst_rdma_rank)[lane_id] = -(channel_id == 0 ? 0 : gbl_channel_prefix_matrix[(dst_rdma_rank * NUM_MAX_NVL_PEERS + lane_id) * num_channels + channel_id - 1]) - 1;
+                dst_ptr[lane_id] = -(channel_id == 0 ? 0 : gbl_channel_prefix_matrix[(dst_rdma_rank * NUM_MAX_NVL_PEERS + lane_id) * num_channels + channel_id - 1]) - 1;
             } else if (lane_id < NUM_MAX_NVL_PEERS * 2) {
-                rdma_channel_meta.send_buffer(dst_rdma_rank)[lane_id] = -gbl_channel_prefix_matrix[(dst_rdma_rank * NUM_MAX_NVL_PEERS + lane_id - NUM_MAX_NVL_PEERS) * num_channels + channel_id] - 1;
+                dst_ptr[lane_id] = -gbl_channel_prefix_matrix[(dst_rdma_rank * NUM_MAX_NVL_PEERS + lane_id - NUM_MAX_NVL_PEERS) * num_channels + channel_id] - 1;
             } else if (lane_id == NUM_MAX_NVL_PEERS * 2) {
-                rdma_channel_meta.send_buffer(dst_rdma_rank)[lane_id] = -(channel_id == 0 ? 0 : rdma_channel_prefix_matrix[dst_rdma_rank * num_channels + channel_id - 1]) - 1;
+                dst_ptr[lane_id] = -(channel_id == 0 ? 0 : rdma_channel_prefix_matrix[dst_rdma_rank * num_channels + channel_id - 1]) - 1;
             } else if (lane_id == NUM_MAX_NVL_PEERS * 2 + 1) {
-                rdma_channel_meta.send_buffer(dst_rdma_rank)[lane_id] = -rdma_channel_prefix_matrix[dst_rdma_rank * num_channels + channel_id] - 1;
+                dst_ptr[lane_id] = -rdma_channel_prefix_matrix[dst_rdma_rank * num_channels + channel_id] - 1;
+            }
+            __syncwarp();
+
+            // Issue RDMA for non-local ranks
+            if (dst_rdma_rank != rdma_rank) {
+                nvshmemi_ibgda_put_nbi_warp<true>(reinterpret_cast<uint64_t>(rdma_channel_meta.recv_buffer(rdma_rank)),
+                                                  reinterpret_cast<uint64_t>(rdma_channel_meta.send_buffer(dst_rdma_rank)),
+                                                  sizeof(int) * (NUM_MAX_NVL_PEERS * 2 + 2),
+                                                  translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank),
+                                                  channel_id, lane_id, 0);
             }
-            nvshmemx_int_put_nbi_warp(rdma_channel_meta.recv_buffer(rdma_rank), rdma_channel_meta.send_buffer(dst_rdma_rank), NUM_MAX_NVL_PEERS * 2 + 2,
-                                      translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
         }
-        nvshmem_fence();
         sync_rdma_sender_smem();
 
         // Iterate over tokens and copy into buffer
@@ -710,11 +721,11 @@ dispatch(int4* recv_x, float* recv_x_scales, int64_t* recv_topk_idx, float* recv
                 if (dst_rdma_rank != rdma_rank) {
                     auto dst_slot_idx = synced_last_issued_tail % num_max_rdma_chunked_recv_tokens;
                     EP_DEVICE_ASSERT(dst_slot_idx + num_tokens_to_issue <= num_max_rdma_chunked_recv_tokens);
-                    nvshmemx_int8_put_nbi_warp(rdma_channel_data.recv_buffer(rdma_rank) + dst_slot_idx * num_bytes_per_rdma_token,
-                                               rdma_channel_data.send_buffer(dst_rdma_rank) + dst_slot_idx * num_bytes_per_rdma_token,
-                                               num_bytes_per_rdma_token * num_tokens_to_issue,
-                                               translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
-                    nvshmem_fence();
+                    const size_t num_bytes_per_msg = num_bytes_per_rdma_token * num_tokens_to_issue;
+                    const auto dst_ptr = reinterpret_cast<uint64_t>(rdma_channel_data.recv_buffer(rdma_rank) + dst_slot_idx * num_bytes_per_rdma_token);
+                    const auto src_ptr = reinterpret_cast<uint64_t>(rdma_channel_data.send_buffer(dst_rdma_rank) + dst_slot_idx * num_bytes_per_rdma_token);
+                    nvshmemi_ibgda_put_nbi_warp<true>(dst_ptr, src_ptr, num_bytes_per_msg,
+                                                      translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank), channel_id, lane_id, 0);
                 } else {
                     // Lighter fence for local RDMA rank
                     memory_fence();
@@ -725,8 +736,8 @@ dispatch(int4* recv_x, float* recv_x_scales, int64_t* recv_topk_idx, float* recv
                 if (lane_id == dst_rdma_rank) {
                     last_issued_tail += num_tokens_to_issue;
                     num_tokens_to_send -= num_tokens_to_issue;
-                    nvshmemx_signal_op(rdma_channel_tail.buffer(rdma_rank), num_tokens_to_issue, NVSHMEM_SIGNAL_ADD,
-                                       translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
+                    nvshmemi_ibgda_amo_nonfetch_add(rdma_channel_tail.buffer(rdma_rank), num_tokens_to_issue,
+                                                    translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank), channel_id, dst_rdma_rank == rdma_rank);
                 }
             }
         }
@@ -926,8 +937,8 @@ dispatch(int4* recv_x, float* recv_x_scales, int64_t* recv_topk_idx, float* recv
 
             // Update remote head
             if (min_head != std::numeric_limits<int>::max() and min_head >= last_head + num_max_rdma_chunked_send_tokens and lane_id < kNumRDMARanks) {
-                nvshmemx_signal_op(rdma_channel_head.buffer(rdma_rank), min_head - last_head, NVSHMEM_SIGNAL_ADD,
-                                   translate_dst_rdma_rank<kLowLatencyMode>(lane_id, nvl_rank));
+                nvshmemi_ibgda_amo_nonfetch_add(rdma_channel_head.buffer(rdma_rank), min_head - last_head,
+                                                translate_dst_rdma_rank<kLowLatencyMode>(lane_id, nvl_rank), channel_id, lane_id == rdma_rank);
                 last_head = min_head;
             }
 
@@ -1558,20 +1569,21 @@ combine(int4* combined_x, float* combined_topk_weights,
                 if (sub_warp_id == kNumWarpsPerForwarder - 1) {
                     if (dst_rdma_rank != rdma_rank) {
                         auto rdma_slot_idx = token_start_idx % num_max_rdma_chunked_recv_tokens;
-                        nvshmemx_int8_put_nbi_warp(rdma_channel_data.recv_buffer(rdma_rank) + rdma_slot_idx * num_bytes_per_rdma_token,
-                                                   rdma_channel_data.send_buffer(dst_rdma_rank) + rdma_slot_idx * num_bytes_per_rdma_token,
-                                                   num_chunked_tokens * num_bytes_per_rdma_token,
-                                                   translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
-                        nvshmem_fence();
+                        const size_t num_bytes_per_msg = num_chunked_tokens * num_bytes_per_rdma_token;
+                        const auto dst_ptr = reinterpret_cast<uint64_t>(rdma_channel_data.recv_buffer(rdma_rank) + rdma_slot_idx * num_bytes_per_rdma_token);
+                        const auto src_ptr = reinterpret_cast<uint64_t>(rdma_channel_data.send_buffer(dst_rdma_rank) + rdma_slot_idx * num_bytes_per_rdma_token);
+                        nvshmemi_ibgda_put_nbi_warp<true>(dst_ptr, src_ptr, num_bytes_per_msg,
+                                                          translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank), channel_id, lane_id, 0);
                     } else {
                         memory_fence();
                     }
 
                     // Write new RDMA tail
                     __syncwarp();
-                    if (lane_id == 0)
-                        nvshmemx_signal_op(rdma_channel_tail.buffer(rdma_rank), num_chunked_tokens, NVSHMEM_SIGNAL_ADD,
-                                           translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
+                    if (lane_id == 0) {
+                        nvshmemi_ibgda_amo_nonfetch_add(rdma_channel_tail.buffer(rdma_rank), num_chunked_tokens,
+                                                        translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank), channel_id, dst_rdma_rank == rdma_rank);
+                    }
                 }
             }
 
@@ -1656,8 +1668,8 @@ combine(int4* combined_x, float* combined_topk_weights,
                     for (int i = 0; i < kNumRDMAReceivers; ++ i) if (not rdma_receiver_retired[i])
                         min_head = min(min_head, rdma_receiver_rdma_head[i][dst_rdma_rank]);
                     if (min_head != std::numeric_limits<int>::max() and min_head >= last_rdma_head + num_max_rdma_chunked_send_tokens and lane_id < kNumRDMARanks) {
-                        nvshmemx_signal_op(rdma_channel_head.buffer(rdma_rank), min_head - last_rdma_head, NVSHMEM_SIGNAL_ADD,
-                                           translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank));
+                        nvshmemi_ibgda_amo_nonfetch_add(rdma_channel_head.buffer(rdma_rank), min_head - last_rdma_head,
+                                                        translate_dst_rdma_rank<kLowLatencyMode>(dst_rdma_rank, nvl_rank), channel_id, dst_rdma_rank == rdma_rank);
                         last_rdma_head = min_head;
                     }
                 } else {

csrc/kernels/internode_ll.cu

@@ -167,7 +167,7 @@ dispatch(void* packed_recv_x, float* packed_recv_x_scales,
         EP_DEVICE_ASSERT(num_sms > 1);
         if (sm_id == 0) {
             // The first SM is also responsible for checking QPs
-            EP_DEVICE_ASSERT(ibgda_get_state()->num_rc_per_pe == num_local_experts);
+            EP_DEVICE_ASSERT(ibgda_get_state()->num_rc_per_pe >= num_local_experts);
 
             // The first SM is also responsible for cleaning the next buffer
             #pragma unroll

csrc/kernels/runtime.cu

@@ -58,14 +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
-    if (low_latency_mode) {
+    // 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

@@ -31,7 +31,7 @@ class Buffer:
 
     def __init__(self, group: dist.ProcessGroup,
                  num_nvl_bytes: int = 0, num_rdma_bytes: int = 0,
-                 low_latency_mode: bool = False, num_qps_per_rank: int = 1) -> None:
+                 low_latency_mode: bool = False, num_qps_per_rank: int = 12) -> None:
         """
         Initialize the communication buffer.
 
@@ -66,8 +66,7 @@ class Buffer:
         # Synchronize NVSHMEM unique IDs
         root_unique_id = None
         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:
+            # Enable IBGDA 
             assert num_qps_per_rank > 0
             os.environ['NVSHMEM_DISABLE_P2P'] = '1'
             os.environ['NVSHMEM_IB_ENABLE_IBGDA'] = '1'

tests/test_internode.py

@@ -219,16 +219,19 @@ def test_main(num_sms: int, local_rank: int, num_local_ranks: int, num_ranks: in
 def test_loop(local_rank: int, num_local_ranks: int):
     num_nodes = int(os.getenv('WORLD_SIZE', 1))
     rank, num_ranks, group = init_dist(local_rank, num_local_ranks)
-    test_ll_compatibility = False
+    test_ll_compatibility = True
     if test_ll_compatibility:
         ll_num_tokens, ll_hidden, ll_num_experts, ll_num_topk = 16, 5120, 256, 9
 
+    num_sms = 24
+    num_qps_per_rank = max(num_sms // 2, ll_num_experts // num_ranks if test_ll_compatibility else 0)
+
     buffer = deep_ep.Buffer(group, int(1e9), int(1e9), low_latency_mode=test_ll_compatibility,
-                            num_qps_per_rank=(ll_num_experts // num_ranks if test_ll_compatibility else 1))
+                            num_qps_per_rank=num_qps_per_rank)
     assert num_local_ranks == 8 and num_ranks > 8
     torch.manual_seed(rank)
 
-    for i in (24, ):
+    for i in (num_sms, ):
         test_main(i, local_rank, num_local_ranks, num_ranks, num_nodes, rank, buffer, group)
         if local_rank == 0:
             print('', flush=True)