[Kernel][Core] Add AWQ support to the Marlin kernel (#6612)

vllm/model_executor/layers/quantization/awq_marlin.py

@@ -0,0 +1,268 @@
+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,
+                                               set_weight_attrs)
+from vllm.model_executor.layers.quantization.base_config import (
+    QuantizationConfig)
+from vllm.model_executor.layers.quantization.utils.marlin_utils import (
+    apply_awq_marlin_linear, awq_to_marlin_zero_points,
+    check_awq_marlin_supported, marlin_make_empty_g_idx, marlin_make_workspace,
+    marlin_permute_scales, replace_tensor, verify_awq_marlin_supported,
+    verify_marlin_supports_shape)
+from vllm.model_executor.layers.vocab_parallel_embedding import ParallelLMHead
+
+logger = init_logger(__name__)
+
+
+class AWQMarlinConfig(QuantizationConfig):
+    """Config class for AWQ Marlin"""
+
+    def __init__(self, weight_bits: int, group_size: int, has_zp: bool,
+                 lm_head_quantized: bool) -> None:
+        self.weight_bits = weight_bits
+        self.pack_factor = 32 // self.weight_bits  # packed into int32
+        self.group_size = group_size
+        self.has_zp = has_zp
+        self.lm_head_quantized = lm_head_quantized
+
+        verify_awq_marlin_supported(num_bits=self.weight_bits,
+                                    group_size=self.group_size,
+                                    has_zp=self.has_zp)
+
+    def __repr__(self) -> str:
+        return (f"AWQMarlinConfig(weight_bits={self.weight_bits}, "
+                f"group_size={self.group_size}, "
+                f"has_zp={self.has_zp}, "
+                f"lm_head_quantized={self.lm_head_quantized})")
+
+    @classmethod
+    def get_name(cls) -> str:
+        return "awq_marlin"
+
+    @classmethod
+    def get_supported_act_dtypes(cls) -> List[torch.dtype]:
+        return [torch.half, torch.bfloat16]
+
+    @classmethod
+    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]) -> "AWQMarlinConfig":
+        weight_bits = cls.get_from_keys(config, ["bits"])
+        group_size = cls.get_from_keys(config, ["group_size"])
+        has_zp = cls.get_from_keys(config, ["zero_point"])
+        lm_head_quantized = cls.get_from_keys_or(config, ["lm_head"],
+                                                 default=False)
+        return cls(weight_bits, group_size, has_zp, lm_head_quantized)
+
+    @classmethod
+    def override_quantization_method(cls, hf_quant_cfg,
+                                     user_quant) -> Optional[str]:
+        can_convert = cls.is_awq_marlin_compatible(hf_quant_cfg)
+        is_valid_user_quant = (user_quant is None or user_quant == "marlin")
+
+        if can_convert and is_valid_user_quant:
+            msg = ("The model is convertible to {} during runtime."
+                   " Using {} kernel.".format(cls.get_name(), cls.get_name()))
+            logger.info(msg)
+            return cls.get_name()
+
+        if can_convert and user_quant == "awq":
+            logger.info("Detected that the model can run with awq_marlin"
+                        ", however you specified quantization=awq explicitly,"
+                        " so forcing awq. Use quantization=awq_marlin for"
+                        " faster inference")
+        return None
+
+    def get_quant_method(self, layer: torch.nn.Module,
+                         prefix: str) -> Optional["AWQMarlinLinearMethod"]:
+        if (isinstance(layer, LinearBase) or
+            (isinstance(layer, ParallelLMHead) and self.lm_head_quantized)):
+            return AWQMarlinLinearMethod(self)
+        return None
+
+    def get_scaled_act_names(self) -> List[str]:
+        return []
+
+    @classmethod
+    def is_awq_marlin_compatible(cls, quant_config: Dict[str, Any]):
+        # Extract data from quant config.
+        quant_method = quant_config.get("quant_method", "").lower()
+        num_bits = quant_config.get("bits", None)
+        group_size = quant_config.get("group_size", None)
+        has_zp = quant_config.get("zero_point", None)
+
+        if quant_method != "awq":
+            return False
+
+        # If we cannot find the info needed in the config, cannot convert.
+        if (num_bits is None or group_size is None or has_zp is None):
+            return False
+
+        return check_awq_marlin_supported(
+            num_bits=num_bits,
+            group_size=group_size,
+            has_zp=has_zp,
+            min_capability=cls.get_min_capability())
+
+
+class AWQMarlinLinearMethod(LinearMethodBase):
+    """Linear method for AWQ Marlin.
+
+    Args:
+        quant_config: The AWQ Marlin quantization config.
+    """
+
+    def __init__(self, quant_config: AWQMarlinConfig) -> None:
+        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,
+    ) -> None:
+        del output_size
+        output_size_per_partition = sum(output_partition_sizes)
+
+        # Normalize group_size
+        if self.quant_config.group_size != -1:
+            group_size = self.quant_config.group_size
+        else:
+            group_size = input_size
+
+        verify_marlin_supports_shape(
+            output_size_per_partition=output_size_per_partition,
+            input_size_per_partition=input_size_per_partition,
+            input_size=input_size,
+            group_size=group_size)
+
+        qweight = Parameter(
+            torch.empty(
+                input_size_per_partition,
+                output_size_per_partition // self.quant_config.pack_factor,
+                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,
+            })
+
+        num_groups = input_size_per_partition // group_size
+
+        qzeros = Parameter(
+            torch.empty(
+                num_groups,
+                output_size_per_partition // self.quant_config.pack_factor,
+                dtype=torch.int32,
+            ),
+            requires_grad=False,
+        )
+        set_weight_attrs(
+            qzeros, {
+                "input_dim": 0,
+                "output_dim": 1,
+                "packed_dim": 1,
+                "pack_factor": self.quant_config.pack_factor,
+            })
+
+        scales = Parameter(
+            torch.empty(
+                num_groups,
+                output_size_per_partition,
+                dtype=params_dtype,
+            ),
+            requires_grad=False,
+        )
+        set_weight_attrs(scales, {
+            "input_dim": 0,
+            "output_dim": 1,
+        })
+
+        layer.register_parameter("qweight", qweight)
+        set_weight_attrs(qweight, extra_weight_attrs)
+        layer.register_parameter("qzeros", qzeros)
+        set_weight_attrs(qzeros, extra_weight_attrs)
+        layer.register_parameter("scales", scales)
+        set_weight_attrs(scales, extra_weight_attrs)
+
+        layer.input_size_per_partition = input_size_per_partition
+        layer.output_size_per_partition = output_size_per_partition
+        layer.num_groups = num_groups
+
+    # TODO: Update this docs
+    # Checkpoints are serialized in AutoAWQ format, which is different from the
+    # marlin format. This function is called after the weights are loaded.
+    # Here, we handle the repacking
+    def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
+        device = layer.qweight.device
+
+        # Allocate marlin workspace
+        layer.workspace = marlin_make_workspace(
+            layer.output_size_per_partition, device)
+
+        # Repack weights from AWQ format to marlin format.
+        marlin_qweight = ops.awq_marlin_repack(
+            layer.qweight,
+            size_k=layer.input_size_per_partition,
+            size_n=layer.output_size_per_partition,
+            num_bits=self.quant_config.weight_bits)
+        replace_tensor(layer, "qweight", marlin_qweight)
+
+        # Permute scales from AWQ format to marlin format.
+        marlin_scales = marlin_permute_scales(
+            layer.scales,
+            size_k=layer.input_size_per_partition,
+            size_n=layer.output_size_per_partition,
+            group_size=self.quant_config.group_size)
+        replace_tensor(layer, "scales", marlin_scales)
+
+        # Permute zero-points from AWQ format to marlin format.
+        marlin_zp = awq_to_marlin_zero_points(
+            layer.qzeros,
+            size_k=layer.num_groups,
+            size_n=layer.output_size_per_partition,
+            num_bits=self.quant_config.weight_bits)
+        replace_tensor(layer, "qzeros", marlin_zp)
+
+        # Not-used
+        layer.g_idx = marlin_make_empty_g_idx(device)
+        layer.g_idx_sort_indices = marlin_make_empty_g_idx(device)
+
+    def apply(
+        self,
+        layer: torch.nn.Module,
+        x: torch.Tensor,
+        bias: Optional[torch.Tensor] = None,
+    ) -> torch.Tensor:
+        return apply_awq_marlin_linear(
+            input=x,
+            weight=layer.qweight,
+            weight_scale=layer.scales,
+            weight_zp=layer.qzeros,
+            g_idx=layer.g_idx,
+            g_idx_sort_indices=layer.g_idx_sort_indices,
+            workspace=layer.workspace,
+            num_bits=self.quant_config.weight_bits,
+            output_size_per_partition=layer.output_size_per_partition,
+            input_size_per_partition=layer.input_size_per_partition,
+            bias=bias)