[ Kernel ] AWQ Fused MoE

csrc/ops.h

@@ -72,6 +72,14 @@ torch::Tensor awq_gemm(torch::Tensor _in_feats, torch::Tensor _kernel,
                        torch::Tensor _scaling_factors, torch::Tensor _zeros,
                        int64_t split_k_iters);
 
+torch::Tensor awq_fused_moe(torch::Tensor _in_feats, torch::Tensor _kernel,
+                            torch::Tensor _scaling_factors,
+                            torch::Tensor _zeros, torch::Tensor _topk_weights,
+                            torch::Tensor _sorted_token_ids_ptr,
+                            torch::Tensor _expert_ids_ptr,
+                            torch::Tensor _num_tokens_post_padded,
+                            bool mul_weights, int64_t split_k_iters);
+
 torch::Tensor awq_dequantize(torch::Tensor _kernel,
                              torch::Tensor _scaling_factors,
                              torch::Tensor _zeros, int64_t split_k_iters,

csrc/torch_bindings.cpp

@@ -121,6 +121,10 @@ TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, ops) {
   ops.def("awq_gemm", &awq_gemm);
   ops.impl("awq_gemm", torch::kCUDA, &awq_gemm);
 
+  // Quantized Grouped GEMM for AWQ.
+  ops.def("awq_fused_moe", &awq_fused_moe);
+  ops.impl("awq_fused_moe", torch::kCUDA, &awq_fused_moe);
+
   // Dequantization for AWQ.
   ops.def("awq_dequantize", &awq_dequantize);
   ops.impl("awq_dequantize", torch::kCUDA, &awq_dequantize);

tests/kernels/test_moe.py

@@ -7,8 +7,11 @@
 from transformers import MixtralConfig
 from transformers.models.mixtral.modeling_mixtral import MixtralSparseMoeBlock
 
+from vllm import _custom_ops as ops
 from vllm.model_executor.layers.activation import SiluAndMul
-from vllm.model_executor.layers.fused_moe import fused_moe
+from vllm.model_executor.layers.fused_moe import (fused_experts_awq, fused_moe,
+                                                  fused_topk)
+from vllm.model_executor.layers.quantization.awq import AWQConfig
 from vllm.model_executor.models.mixtral import MixtralMoE
 
 
@@ -99,3 +102,94 @@ def test_mixtral_moe(dtype: torch.dtype):
                           vllm_states,
                           rtol=mixtral_moe_tol[dtype],
                           atol=mixtral_moe_tol[dtype])
+
+
+def torch_moe_awq(a, w1, w1_scale, w1_zero, w2, w2_scale, w2_zero, score,
+                  topk):
+    score = torch.softmax(score.float(), dim=-1)
+    topk_weight, topk_ids = torch.topk(score, topk)
+    (B, D) = a.shape
+    a = a.view(B, -1, D).repeat(1, topk_ids.shape[1], 1).reshape(-1, D)
+    out = torch.zeros(B * topk_ids.shape[1],
+                      w2.shape[2] * 8,
+                      dtype=a.dtype,
+                      device=a.device)
+    topk_ids = topk_ids.view(-1)
+    topk_weight = topk_weight.view(-1)
+    for i in range(w1.shape[0]):
+        mask = topk_ids == i
+        if mask.sum():
+            dw1 = ops.awq_dequantize(w1[i], w1_scale[i], w1_zero[i], 0, 0, 0)
+            dw2 = ops.awq_dequantize(w2[i], w2_scale[i], w2_zero[i], 0, 0, 0)
+            r1 = SiluAndMul()(torch.matmul(a[mask].half(), dw1))
+            out[mask] = torch.matmul(r1, dw2).to(out.dtype)
+    return (out.view(B, -1, w2.shape[2] * 8) *
+            topk_weight.view(B, -1, 1)).sum(dim=1).half()
+
+
+@pytest.mark.parametrize("m", [1024, 222, 33, 1])
+@pytest.mark.parametrize("n", [2048, 256, 1024])
+@pytest.mark.parametrize("k", [128, 512, 1024])
+@pytest.mark.parametrize("e", [8])
+@pytest.mark.parametrize("topk", [2, 6])
+def test_fused_moe_awq(
+    m: int,
+    n: int,
+    k: int,
+    e: int,
+    topk: int,
+):
+    # awq requires minimum capability 75
+    if torch.version.hip is not None:
+        return
+    capability = torch.cuda.get_device_capability()
+    capability = capability[0] * 10 + capability[1]
+    if capability < 75:
+        return
+
+    RANGE = 1000000000
+    groupsize = 128
+    a = torch.randn((m, k), device='cuda', dtype=torch.half) / 10
+    qw1 = torch.randint(-RANGE,
+                        RANGE, (e, k, n * 2 // 8),
+                        dtype=torch.int,
+                        device='cuda')
+    qw2 = torch.randint(-RANGE,
+                        RANGE, (e, n, k // 8),
+                        dtype=torch.int,
+                        device='cuda')
+
+    scale1 = torch.randn(
+        (e, k // groupsize, n * 2), dtype=torch.half, device='cuda') / 50
+    scale2 = torch.randn(
+        (e, n // groupsize, k), dtype=torch.half, device='cuda') / 50
+
+    zero1 = torch.randint(-RANGE,
+                          RANGE, (e, k // groupsize, (n * 2 // 32) * 4),
+                          dtype=torch.int32,
+                          device='cuda')
+    zero2 = torch.randint(-RANGE,
+                          RANGE, (e, n // groupsize, (k // 32) * 4),
+                          dtype=torch.int32,
+                          device='cuda')
+    w1 = {"qweight": qw1, "scales": scale1, "qzeros": zero1}
+    w2 = {"qweight": qw2, "scales": scale2, "qzeros": zero2}
+
+    score = torch.randn((m, e), device='cuda', dtype=torch.half)
+
+    quant_config = AWQConfig(4, groupsize, False)
+    torch_output = torch_moe_awq(a, qw1, scale1, zero1, qw2, scale2, zero2,
+                                 score, topk)
+
+    topk_weights, topk_ids = fused_topk(a, score, topk, renormalize=False)
+    cuda_output = fused_experts_awq(hidden_states=a,
+                                    w1=w1["qweight"],
+                                    w2=w2["qweight"],
+                                    w1_scales=w1["scales"],
+                                    w2_scales=w2["scales"],
+                                    w1_qzeros=w1["qzeros"],
+                                    w2_qzeros=w2["qzeros"],
+                                    topk_weights=topk_weights,
+                                    topk_ids=topk_ids,
+                                    pack_factor=quant_config.pack_factor)
+    assert torch.allclose(cuda_output, torch_output, atol=1e-2, rtol=0)

vllm/_custom_ops.py

@@ -192,6 +192,17 @@ def awq_gemm(input: torch.Tensor, qweight: torch.Tensor, qzeros: torch.Tensor,
     return torch.ops._C.awq_gemm(input, qweight, qzeros, scales, split_k_iters)
 
 
+def awq_fused_moe(input: torch.Tensor, qweight: torch.Tensor,
+                  scales: torch.Tensor, qzeros: torch.Tensor,
+                  topk_weights: torch.Tensor, sorted_token_ids: torch.Tensor,
+                  expert_ids: torch.Tensor, num_tokens_post_padded: int,
+                  mul_weights: bool, pack_factor: int) -> torch.Tensor:
+    return torch.ops._C.awq_fused_moe(input, qweight, scales, qzeros,
+                                      topk_weights, sorted_token_ids,
+                                      expert_ids, num_tokens_post_padded,
+                                      mul_weights, pack_factor)
+
+
 # gptq
 def gptq_gemm(a: torch.Tensor, b_q_weight: torch.Tensor,
               b_gptq_qzeros: torch.Tensor, b_gptq_scales: torch.Tensor,

vllm/model_executor/layers/fused_moe/__init__.py

@@ -1,8 +1,11 @@
+from vllm.model_executor.layers.fused_moe.fused_moe_awq import (
+    fused_experts_awq)
 from vllm.model_executor.layers.fused_moe.layer import (FusedMoE,
                                                         FusedMoEMethodBase)
 from vllm.triton_utils import HAS_TRITON
 
 __all__ = [
+    "fused_experts_awq",
     "FusedMoE",
     "FusedMoEMethodBase",
 ]
@@ -15,8 +18,8 @@
 
     __all__ += [
         "fused_moe",
-        "fused_topk",
         "fused_experts",
+        "fused_topk",
         "get_config_file_name",
         "grouped_topk",
     ]

vllm/model_executor/layers/fused_moe/fused_moe_awq.py

@@ -0,0 +1,73 @@
+"""Fused MoE utilities for AWQ."""
+import torch
+
+from vllm import _custom_ops as ops
+from vllm.logger import init_logger
+from vllm.model_executor.layers.fused_moe.fused_moe import (
+    fused_experts, moe_align_block_size)
+
+logger = init_logger(__name__)
+
+NAIVE_THRESHOLD = 1024
+
+
+def fused_experts_awq(
+    hidden_states: torch.Tensor,
+    w1: torch.Tensor,
+    w2: torch.Tensor,
+    w1_scales: torch.Tensor,
+    w2_scales: torch.Tensor,
+    w1_qzeros: torch.Tensor,
+    w2_qzeros: torch.Tensor,
+    topk_weights: torch.Tensor,
+    topk_ids: torch.Tensor,
+    pack_factor: int,
+) -> torch.Tensor:
+    """
+    This function computes an AWQ fused_expert.
+
+    Parameters:
+    - hidden_states (torch.Tensor): The input tensor to the MoE layer.
+    - w1 (torch.Tensor): The first set of expert weights.
+    - w2 (torch.Tensor): The second set of expert weights.    
+    - w1_scales (torch.Tensor): scale to be used for w1.
+    - w2_scales (torch.Tensor): scale to be used for w2.
+    - w1_qzeros (torch.Tensor): zero point to be used for w1.
+    - w2_qzeros (torch.Tensor): zero point to be used for w2.
+    - pack_factor (int): Weight packing factor (int4 in int32 == 8)
+
+    Returns:
+    - torch.Tensor: The output tensor after applying the MoE layer.
+    """
+
+    # If large seq_len prefill, dequantize and use the fp16 MoE kernel.
+    do_naive_dequant = hidden_states.shape[:-1].numel() >= NAIVE_THRESHOLD
+    if do_naive_dequant:
+        # NOTE: not contiguous because of the permutation operation
+        dequant_w1 = ops.awq_dequantize(w1, w1_scales, w1_qzeros, 0, 0,
+                                        0).permute(0, 2, 1).contiguous()
+        dequant_w2 = ops.awq_dequantize(w2, w2_scales, w2_qzeros, 0, 0,
+                                        0).permute(0, 2, 1).contiguous()
+
+        return fused_experts(hidden_states, dequant_w1, dequant_w2,
+                             topk_weights, topk_ids)
+
+    (sorted_token_ids, expert_ids,
+     num_tokens_post_padded) = moe_align_block_size(topk_ids, 16, w1.shape[0])
+
+    x = hidden_states.view(hidden_states.shape[0], 1, *hidden_states.shape[1:])
+
+    gate_up = ops.awq_fused_moe(x, w1, w1_scales, w1_qzeros, topk_weights,
+                                sorted_token_ids, expert_ids,
+                                num_tokens_post_padded, False, pack_factor)
+
+    out = torch.empty((gate_up.shape[:-1] + (gate_up.shape[-1] // 2, )),
+                      dtype=hidden_states.dtype,
+                      device=hidden_states.device)
+    ops.silu_and_mul(out, gate_up)
+
+    out = ops.awq_fused_moe(out, w2, w2_scales, w2_qzeros, topk_weights,
+                            sorted_token_ids, expert_ids,
+                            num_tokens_post_padded, True, pack_factor)
+
+    return torch.sum(out, dim=1)