Add GPTQ Marlin 2:4 sparse structured support (#4790)

Co-authored-by: Robert Shaw <rshaw@neuralmagic.com>

vllm/model_executor/layers/quantization/gptq_marlin_24.py

@@ -0,0 +1,280 @@
+from typing import Any, Dict, List, Optional
+
+import torch
+from torch.nn.parameter import Parameter
+
+from vllm import _custom_ops as ops
+from vllm.logger import init_logger
+from vllm.model_executor.layers.linear import LinearBase, LinearMethodBase
+from vllm.model_executor.layers.quantization.base_config import (
+    QuantizationConfig)
+from vllm.model_executor.utils import set_weight_attrs
+
+logger = init_logger(__name__)
+
+
+class GPTQMarlin24Config(QuantizationConfig):
+    """Config class for Marlin24.
+    """
+
+    def __init__(
+        self,
+        weight_bits: int,
+        group_size: int,
+    ) -> None:
+        self.weight_bits = weight_bits
+        self.group_size = group_size
+
+        if self.weight_bits != 4 and self.weight_bits != 8:
+            raise ValueError("weight_bits must be 4 or 8. Got = {}".format(
+                self.weight_bits))
+
+        if self.group_size != 128 and self.group_size != -1:
+            raise ValueError(
+                "Currently, only group size 128 and -1 (channelwise) "
+                "is supported for Marlin24, but got group_size of "
+                f"{self.group_size}")
+
+        # 4 Bits packed into 32 bit datatype.
+        self.pack_factor = 32 // self.weight_bits
+
+        # Tile size used by marlin kernels.
+        self.tile_size = 16
+
+        # Min out_features dim
+        self.min_n_threads = 128
+
+        # Min in_features dim
+        self.min_k_threads = 128
+
+        # Max parallel problems to solve at once (improves large
+        # batch performance)
+        self.max_parallel = 16
+
+        # Permutation length used by the marlin kernels.
+        self.perm_len = 1024
+
+    def __repr__(self) -> str:
+        return "Marlin24Config(weight_bits={}, group_size={})".format(
+            self.weight_bits, self.group_size)
+
+    @classmethod
+    def get_name(cls) -> str:
+        return "gptq_marlin_24"
+
+    @classmethod
+    def get_supported_act_dtypes(cls) -> List[torch.dtype]:
+        return [torch.half]
+
+    @classmethod
+    # Need to figure it out
+    def get_min_capability(cls) -> int:
+        return 80
+
+    @classmethod
+    def get_config_filenames(cls) -> List[str]:
+        return ["quantize_config.json"]
+
+    @classmethod
+    def from_config(cls, config: Dict[str, Any]) -> "GPTQMarlin24Config":
+        weight_bits = cls.get_from_keys(config, ["bits"])
+        group_size = cls.get_from_keys(config, ["group_size"])
+        return cls(weight_bits, group_size)
+
+    @classmethod
+    def override_quantization_method(cls, hf_quant_cfg,
+                                     user_quant) -> Optional[str]:
+        is_marlin_24_format = (
+            hf_quant_cfg.get("checkpoint_format") == "marlin_24")
+
+        is_valid_user_quant = (user_quant is None or user_quant == "gptq"
+                               or user_quant == "gptq_marlin_24")
+
+        if is_marlin_24_format and is_valid_user_quant:
+            msg = ("The model is serialized in {} format. "
+                   "Using {} kernel.".format(cls.get_name(), cls.get_name()))
+            logger.info(msg)
+            return cls.get_name()
+
+        return None
+
+    def get_quant_method(
+            self,
+            layer: torch.nn.Module) -> Optional["GPTQMarlin24LinearMethod"]:
+        if isinstance(layer, LinearBase):
+            return GPTQMarlin24LinearMethod(self)
+        return None
+
+    def get_scaled_act_names(self) -> List[str]:
+        return []
+
+
+class GPTQMarlin24LinearMethod(LinearMethodBase):
+    """Linear method for Marlin24.
+
+    Args:
+        quant_config: The Marlin24 quantization config.
+    """
+
+    def __init__(self, quant_config: GPTQMarlin24Config):
+        self.quant_config = quant_config
+
+    def create_weights(
+        self,
+        layer: torch.nn.Module,
+        input_size_per_partition: int,
+        output_partition_sizes: List[int],
+        input_size: int,
+        output_size: int,
+        params_dtype: torch.dtype,
+        **extra_weight_attrs,
+    ):
+        del output_size  # Unused.
+
+        if params_dtype != torch.float16:
+            raise ValueError(
+                f"The params dtype must be float16, but got {params_dtype}")
+
+        # Validate output_size_per_partition
+        output_size_per_partition = sum(output_partition_sizes)
+        if output_size_per_partition % self.quant_config.min_n_threads != 0:
+            raise ValueError(
+                f"Weight output_size_per_partition = "
+                f"{output_size_per_partition} is not divisible by "
+                f"min_n_threads = {self.quant_config.min_n_threads}.")
+        if output_size_per_partition % self.quant_config.pack_factor != 0:
+            raise ValueError(
+                f"Weight output_size_per_partition = "
+                f"{output_size_per_partition} is not divisible by "
+                f"pack_factor = {self.quant_config.pack_factor}.")
+
+        # Validate input_size_per_partition
+        if input_size_per_partition % self.quant_config.min_k_threads != 0:
+            raise ValueError(
+                f"Weight input_size_per_partition = "
+                f"{input_size_per_partition} is not divisible by "
+                f"min_k_threads = {self.quant_config.min_k_threads}.")
+        if (self.quant_config.group_size != -1 and
+                input_size_per_partition % self.quant_config.group_size != 0):
+            raise ValueError(f"Weight input_size_per_partition = "
+                             f"{input_size_per_partition} is not divisible by "
+                             f"group_size = {self.quant_config.group_size}.")
+
+        # Check that we have at least 4 tiles horizontally in the shard
+        num_tiles_per_perm = self.quant_config.perm_len // (
+            self.quant_config.tile_size**2)
+        if output_size_per_partition % num_tiles_per_perm != 0:
+            raise ValueError(
+                "Each permutation group must reside on the same gpu")
+
+        # Quantized 4Bit weights packed into Int32.
+        qweight = Parameter(
+            torch.empty(
+                input_size_per_partition // self.quant_config.tile_size // 2,
+                output_size_per_partition * self.quant_config.tile_size //
+                self.quant_config.pack_factor,
+                device="cuda",
+                dtype=torch.int32,
+            ),
+            requires_grad=False,
+        )
+        set_weight_attrs(
+            qweight,
+            {
+                "input_dim": 0,
+                "output_dim": 1,
+                "packed_dim": 1,
+                "pack_factor": self.quant_config.pack_factor,
+                "marlin_tile_size": self.quant_config.tile_size,
+            },
+        )
+
+        # Meta
+        meta = Parameter(
+            torch.empty(
+                input_size_per_partition // 8 // 2 // 2,
+                output_size_per_partition * 2,
+                device="cuda",
+                dtype=torch.int16,
+            ),
+            requires_grad=False,
+        )
+        set_weight_attrs(
+            meta,
+            {
+                "input_dim": 0,
+                "packed_dim": 1,
+                "pack_factor": 1,
+                "output_dim": 1,
+                "marlin_tile_size": 2,
+            },
+        )
+
+        # Determine if channelwise or not
+        input_groups = (1 if self.quant_config.group_size == -1 else
+                        input_size_per_partition //
+                        self.quant_config.group_size)
+
+        scales = Parameter(
+            torch.empty(
+                input_groups,
+                output_size_per_partition,
+                device="cuda",
+                dtype=params_dtype,
+            ),
+            requires_grad=False,
+        )
+        set_weight_attrs(
+            scales,
+            {
+                "input_dim": None if input_groups == 1 else 0,
+                "output_dim": 1,
+            },
+        )
+
+        # Allocate workspace (Used for internal locking mechanism)
+        max_workspace_size = (
+            output_size_per_partition //
+            self.quant_config.min_n_threads) * self.quant_config.max_parallel
+        workspace = Parameter(torch.zeros(max_workspace_size,
+                                          device="cuda",
+                                          dtype=torch.int),
+                              requires_grad=False)
+
+        layer.register_parameter("B_24", qweight)
+        set_weight_attrs(qweight, extra_weight_attrs)
+        layer.register_parameter("B_meta", meta)
+        set_weight_attrs(meta, extra_weight_attrs)
+        layer.register_parameter("s", scales)
+        set_weight_attrs(scales, extra_weight_attrs)
+        layer.register_parameter("workspace", workspace)
+        set_weight_attrs(workspace, extra_weight_attrs)
+
+    def apply(
+        self,
+        layer: torch.nn.Module,
+        x: torch.Tensor,
+        bias: Optional[torch.Tensor] = None,
+    ) -> torch.Tensor:
+        qweight = layer.B_24
+        meta = layer.B_meta
+        scales = layer.s
+        workspace = layer.workspace
+
+        x_2d = x.view(-1, x.shape[-1])
+
+        size_m = x_2d.shape[0]
+        size_k = x_2d.shape[1]
+        size_n = scales.shape[1]
+
+        output_2d = ops.gptq_marlin_24_gemm(x_2d, qweight, meta, scales,
+                                            workspace,
+                                            self.quant_config.weight_bits,
+                                            size_m, size_n, size_k)
+
+        output = output_2d.view(x.shape[:-1] + (output_2d.shape[1], ))
+
+        if bias is not None:
+            output.add_(bias)  # In-place add
+
+        return output