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vllm.lora.punica_wrapper.punica_gpu

Based on: Chen, L., Ye, Z., Wu, Y., Zhuo, D., Ceze, L., & Krishnamurthy, A. (2023). Punica: Multi-Tenant LoRA Serving. https://arxiv.org/abs/2310.18547

PunicaWrapperGPU

Bases: PunicaWrapperBase

PunicaWrapperGPU is designed to manage and provide metadata for the punica kernel. The main function is to maintain the state information for Multi-LoRA, and to provide the interface for the punica triton kernel.

Source code in vllm/lora/punica_wrapper/punica_gpu.py
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@final
class PunicaWrapperGPU(PunicaWrapperBase):
    """
    PunicaWrapperGPU is designed to manage and provide metadata for the punica
    kernel. The main function is to maintain the state information for
    Multi-LoRA, and to provide the interface for the punica triton kernel.
    """

    def __init__(
        self,
        max_num_batched_tokens: int,
        max_batches: int,
        device: torch.device | str,
        **kwargs,
    ):
        PunicaWrapperBase.__init__(self, max_num_batched_tokens, max_batches, device)

        self.lora_config = kwargs["lora_config"]
        self.max_loras = self.lora_config.max_loras

        # Compute captured LoRA counts for cudagraph specialization.
        captured_lora_counts = get_captured_lora_counts(
            self.max_loras, self.lora_config.specialize_active_lora
        )

        self.token_mapping_meta = LoRAKernelMeta.make(
            self.max_loras,
            max_num_batched_tokens,
            device=device,
            captured_lora_counts=captured_lora_counts,
        )

        # When speculative decoding is enabled, max_num_samples is
        # max_batches * (num_speculative_decoding_tokens + 1).
        # This line can be optimized by replacing max_num_batched_tokens
        # to  max_batches * (num_speculative_decoding_tokens + 1).
        self.prompt_mapping_meta = LoRAKernelMeta.make(
            self.max_loras,
            max_num_batched_tokens,
            device=device,
            captured_lora_counts=captured_lora_counts,
        )

    def update_metadata(
        self,
        mapping: LoRAMapping,
        lora_index_to_id: list[int | None],
        max_loras: int,
        vocab_size: int,
        **kwargs,
    ):
        self.is_prefill = mapping.is_prefill
        self._update_base_metadata(mapping, lora_index_to_id, max_loras, vocab_size)

        # Prepare cuda kernel metadata tensors
        self.token_mapping_meta.prepare_tensors(self.token_lora_indices)
        self.prompt_mapping_meta.prepare_tensors(self.sampler_indices)

    def add_shrink(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_a_stacked: tuple[torch.Tensor, ...],
        scale: float,
        **kwargs,
    ):
        """
        Performs GEMM  for multiple slices of lora_a.

        Semantics:
        for i in range(len(lora_a_stacked)):
            y[i] += (x @ lora_a_stacked[i]) * scale

        Args:
            y (torch.Tensor): Output tensors
            x (torch.Tensor): Input tensor
            lora_a_stacked (tuple[torch.Tensor, ...]): lora_a's weights
            scale (float): Scaling factor for the operation
        """

        x = x.view(-1, x.shape[-1])
        lora_shrink(
            x,
            lora_a_stacked,
            y,
            *self.token_mapping_meta.meta_args(
                x.size(0), self.lora_config.specialize_active_lora
            ),
            scale,
        )

    def add_expand(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_b_stacked: tuple[torch.Tensor, ...],
        output_slices: tuple[int, ...],
        offset_start: int = 0,
        add_inputs=True,
        **kwargs,
    ) -> None:
        """
        Performs GEMM for multiple slices of lora_b.

        Semantics:
            for i in range(len(lora_b_stacked)):
                slice = output_slices[i]
                y[:, offset:offset+slice] += x[i] @ lora_b_stacked[i]
                offset += slice

        Args:
            y (torch.Tensor): Output tensor.
            x (torch.Tensor): Input tensors
            lora_b_stacked (tuple[torch.Tensor, ...]): lora_b's weight
            output_slices (tuple[int, ...]): Every slice's size
            add_inputs (bool): Defaults to True.
        """
        y_org = y
        y = y.view(-1, y.shape[-1])

        assert x.ndim == 3
        assert x.size(0) == len(output_slices)
        num_tokens = x.size(1)  # first dimension is the num slices

        lora_expand(
            x,
            lora_b_stacked,
            y,
            *self.token_mapping_meta.meta_args(
                num_tokens, self.lora_config.specialize_active_lora
            ),
            offset_start=offset_start,
            add_inputs=True,
        )

        y = y.view_as(y_org)

    def add_lora_embedding(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_b_stacked: torch.Tensor,
        add_inputs: bool = True,
        **kwargs,
    ) -> None:
        """
        Applies lora  specifically for VocabParallelEmbeddingWithLoRA.

        Semantics:
            y += x @ lora_b_stacked

        Args:
            y (torch.Tensor): Output tensor.
            x (torch.Tensor): Input tensor.
            lora_b_stacked (torch.Tensor): lora_b's weights.
            add_inputs (bool): Default to True.
        """

        lora_expand(
            x.unsqueeze(dim=0),
            (lora_b_stacked,),
            y,
            *self.token_mapping_meta.meta_args(
                x.size(0), self.lora_config.specialize_active_lora
            ),
            offset_start=0,
            add_inputs=add_inputs,
        )

    def add_lora_linear(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_a_stacked: tuple[torch.Tensor, ...],
        lora_b_stacked: tuple[torch.Tensor, ...],
        scale: float,
        output_slices: tuple[int, ...],
        *,
        buffer: torch.Tensor | None = None,
        **kwargs,
    ) -> None:
        """
        Applicable to linear-related lora.

        Semantics:
            for i in range(len(lora_a_stacked)):
                y[i] += (
                    x[i].unsqueeze(0)
                    @ lora_a_stacked[indices[i], layer_idx, :, :]
                    @ lora_b_stacked[indices[i], layer_idx, :, :]
                    * scale
                    ).squeeze(0)
        Args:
            y (torch.Tensor): Output tensor. Will be changed in-place.
            x (torch.Tensor): Input tensor
            lora_a_stacked (tuple[torch.Tensor, ...]): lora_a's weight.
            lora_b_stacked (tuple[torch.Tensor, ...]): lora_b's weight.
            scale (float): Scaling factor.
            output_slices (tuple[int, ...]): Every slice's size.
            buffer (Optional[torch.Tensor]): Defaults to None.
        """

        assert len(lora_a_stacked) == len(lora_b_stacked) == len(output_slices)

        assert buffer is None, (
            "To minimize overhead, the buffer should be created by "
            ".add_lora_linear() instead of being passed in."
        )
        r = lora_b_stacked[0].size(-1)
        # We set the buffer to be float32 by default, refer to:
        # https://github.com/triton-lang/triton/issues/1387
        # Note: buffer is zeroed inside the shrink op
        buffer = torch.empty(
            (len(output_slices), x.size(0), r), dtype=torch.float32, device=x.device
        )

        self.add_shrink(
            buffer,  # type: ignore
            x,
            lora_a_stacked,
            scale,
            **kwargs,
        )
        self.add_expand(
            y,
            buffer,  # type: ignore
            lora_b_stacked,
            output_slices,
            add_inputs=True,
            **kwargs,
        )

    def add_lora_logits(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_a_stacked: torch.Tensor,
        lora_b_stacked: torch.Tensor,
        scale,
        *,
        buffer: torch.Tensor | None = None,
        **kwargs,
    ) -> None:
        """
        Applies lora  specifically for LogitsProcessorWithLoRA.

        Semantics:
            buffer = (x @ lora_a_stacked) * scale
            y += buffer @ lora_b_stacked

        Args:
            y (torch.Tensor): Output tensor.
            x (torch.Tensor): Input tensor.
            lora_a_stacked (torch.Tensor): lora_a's weights.
            lora_b_stacked (torch.Tensor): lora_b's weights.
            scale (float): Scaling factor.
            buffer (Optional[torch.Tensor]): Default to None.
        """
        y_org = y
        y = y.view(-1, y.shape[-1])
        x = x.view(-1, x.shape[-1])
        r = lora_b_stacked.size(-1)

        assert buffer is None, (
            "To minimize overhead, the buffer should be created by "
            ".add_lora_linear() instead of being passed in."
        )
        # We set the buffer to be float32 by default, refer to:
        # https://github.com/triton-lang/triton/issues/1387
        # Note: buffer is zeroed inside the shrink op
        buffer = torch.empty((x.size(0), r), dtype=torch.float32, device=x.device)

        lora_shrink(
            x,
            [lora_a_stacked],
            buffer.unsqueeze(dim=0),
            *self.prompt_mapping_meta.meta_args(
                x.size(0), self.lora_config.specialize_active_lora
            ),
            scale,
        )

        lora_expand(
            buffer.unsqueeze(dim=0),
            [lora_b_stacked],
            y,
            *self.prompt_mapping_meta.meta_args(
                buffer.size(0), self.lora_config.specialize_active_lora
            ),
            add_inputs=True,
        )
        y = y.view_as(y_org)

    def moe_lora_align_block_size(
        self,
        topk_ids: torch.Tensor,
        num_tokens: int,
        block_size: int,
        num_experts: int,
        max_loras: int,
        adapter_enabled: torch.Tensor,
        expert_map: torch.Tensor | None = None,
        pad_sorted_ids: bool = False,
        naive_block_assignment: bool = False,
    ) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
        """
        Aligns tokens and experts into block-sized chunks for LoRA-based
        mixture-of-experts (MoE) execution.
        """
        (token_lora_mapping, _, _, _, lora_ids, _, _) = (
            self.token_mapping_meta.meta_args(
                num_tokens, self.lora_config.specialize_active_lora
            )
        )
        if naive_block_assignment:
            expert_ids = topk_ids.reshape(-1)
            sorted_ids = None
            num_tokens_post_pad = None
        else:
            max_num_tokens_padded = topk_ids.numel() + num_experts * (block_size - 1)
            if pad_sorted_ids:
                max_num_tokens_padded = round_up(max_num_tokens_padded, block_size)
            sorted_ids = torch.empty(
                (max_loras * max_num_tokens_padded,),
                dtype=torch.int32,
                device=topk_ids.device,
            )
            max_num_m_blocks = triton.cdiv(max_num_tokens_padded, block_size)
            # Expert ids must be set default to -1 to prevent a blank block
            expert_ids = torch.empty(
                (max_loras * max_num_m_blocks,),
                dtype=torch.int32,
                device=topk_ids.device,
            )
            num_tokens_post_pad = torch.empty(
                (max_loras), dtype=torch.int32, device=topk_ids.device
            )

            ops.moe_lora_align_block_size(
                topk_ids,
                token_lora_mapping,
                num_experts,
                block_size,
                max_loras,
                max_num_tokens_padded,
                max_num_m_blocks,
                sorted_ids,
                expert_ids,
                num_tokens_post_pad,
                adapter_enabled,
                lora_ids,
            )
            if expert_map is not None:
                expert_ids = expert_map[expert_ids]

        return None, sorted_ids, expert_ids, num_tokens_post_pad

    def add_lora_fused_moe(
        self,
        y: torch.Tensor,
        x: torch.Tensor,
        lora_a_stacked: tuple[torch.Tensor, ...],
        lora_b_stacked: tuple[torch.Tensor, ...],
        topk_weights: torch.Tensor,
        sorted_token_ids: torch.Tensor | None,
        expert_ids: torch.Tensor,
        num_tokens_post_padded: torch.Tensor | None,
        max_lora_rank: int,
        top_k_num: int,
        shrink_config,
        expand_config,
        adapter_enabled: torch.Tensor,
        mul_routed_weight=False,
        fully_sharded: bool = False,
        offset: int = 0,
        token_lora_mapping: torch.Tensor | None = None,
    ):
        """
        Performs a fused forward computation for LoRA of Mixture-of-Experts (MoE) layer.
        """
        (
            token_lora_mapping_meta,
            _,
            _,
            _,
            lora_ids,
            _,
            num_active_loras,
        ) = self.token_mapping_meta.meta_args(
            x.size(0), self.lora_config.specialize_active_lora
        )
        if token_lora_mapping is None:
            token_lora_mapping = token_lora_mapping_meta
        fused_moe_lora(
            y,
            x,
            lora_a_stacked,
            lora_b_stacked,
            topk_weights,
            sorted_token_ids,
            expert_ids,
            num_tokens_post_padded,
            token_lora_mapping,
            max_lora_rank,
            top_k_num,
            lora_ids,
            num_active_loras,
            adapter_enabled,
            shrink_config.get("BLOCK_SIZE_M", 64),
            shrink_config.get("BLOCK_SIZE_N", 64),
            shrink_config.get("BLOCK_SIZE_K", 32),
            shrink_config.get("GROUP_SIZE_M", 8),
            shrink_config.get("NUM_WARPS", 4),
            shrink_config.get("NUM_STAGES", 3),
            shrink_config.get("SPLIT_K", 1),
            expand_config.get("BLOCK_SIZE_M", 64),
            expand_config.get("BLOCK_SIZE_N", 64),
            expand_config.get("BLOCK_SIZE_K", 32),
            expand_config.get("GROUP_SIZE_M", 8),
            expand_config.get("NUM_WARPS", 4),
            expand_config.get("NUM_STAGES", 3),
            expand_config.get("SPLIT_K", 1),
            mul_routed_weight,
            fully_sharded,
            offset,
        )

lora_config instance-attribute

lora_config = kwargs['lora_config']

max_loras instance-attribute

max_loras = max_loras

prompt_mapping_meta instance-attribute

prompt_mapping_meta = make(
    max_loras,
    max_num_batched_tokens,
    device=device,
    captured_lora_counts=captured_lora_counts,
)

token_mapping_meta instance-attribute

token_mapping_meta = make(
    max_loras,
    max_num_batched_tokens,
    device=device,
    captured_lora_counts=captured_lora_counts,
)

__init__

__init__(
    max_num_batched_tokens: int,
    max_batches: int,
    device: device | str,
    **kwargs,
)
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def __init__(
    self,
    max_num_batched_tokens: int,
    max_batches: int,
    device: torch.device | str,
    **kwargs,
):
    PunicaWrapperBase.__init__(self, max_num_batched_tokens, max_batches, device)

    self.lora_config = kwargs["lora_config"]
    self.max_loras = self.lora_config.max_loras

    # Compute captured LoRA counts for cudagraph specialization.
    captured_lora_counts = get_captured_lora_counts(
        self.max_loras, self.lora_config.specialize_active_lora
    )

    self.token_mapping_meta = LoRAKernelMeta.make(
        self.max_loras,
        max_num_batched_tokens,
        device=device,
        captured_lora_counts=captured_lora_counts,
    )

    # When speculative decoding is enabled, max_num_samples is
    # max_batches * (num_speculative_decoding_tokens + 1).
    # This line can be optimized by replacing max_num_batched_tokens
    # to  max_batches * (num_speculative_decoding_tokens + 1).
    self.prompt_mapping_meta = LoRAKernelMeta.make(
        self.max_loras,
        max_num_batched_tokens,
        device=device,
        captured_lora_counts=captured_lora_counts,
    )

add_expand

add_expand(
    y: Tensor,
    x: Tensor,
    lora_b_stacked: tuple[Tensor, ...],
    output_slices: tuple[int, ...],
    offset_start: int = 0,
    add_inputs=True,
    **kwargs,
) -> None

Performs GEMM for multiple slices of lora_b.

Semantics

for i in range(len(lora_b_stacked)): slice = output_slices[i] y[:, offset:offset+slice] += x[i] @ lora_b_stacked[i] offset += slice

Parameters:

Name Type Description Default
y Tensor

Output tensor.

required
x Tensor

Input tensors

required
lora_b_stacked tuple[Tensor, ...]

lora_b's weight

required
output_slices tuple[int, ...]

Every slice's size

required
add_inputs bool

Defaults to True.

True
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_expand(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_b_stacked: tuple[torch.Tensor, ...],
    output_slices: tuple[int, ...],
    offset_start: int = 0,
    add_inputs=True,
    **kwargs,
) -> None:
    """
    Performs GEMM for multiple slices of lora_b.

    Semantics:
        for i in range(len(lora_b_stacked)):
            slice = output_slices[i]
            y[:, offset:offset+slice] += x[i] @ lora_b_stacked[i]
            offset += slice

    Args:
        y (torch.Tensor): Output tensor.
        x (torch.Tensor): Input tensors
        lora_b_stacked (tuple[torch.Tensor, ...]): lora_b's weight
        output_slices (tuple[int, ...]): Every slice's size
        add_inputs (bool): Defaults to True.
    """
    y_org = y
    y = y.view(-1, y.shape[-1])

    assert x.ndim == 3
    assert x.size(0) == len(output_slices)
    num_tokens = x.size(1)  # first dimension is the num slices

    lora_expand(
        x,
        lora_b_stacked,
        y,
        *self.token_mapping_meta.meta_args(
            num_tokens, self.lora_config.specialize_active_lora
        ),
        offset_start=offset_start,
        add_inputs=True,
    )

    y = y.view_as(y_org)

add_lora_embedding

add_lora_embedding(
    y: Tensor,
    x: Tensor,
    lora_b_stacked: Tensor,
    add_inputs: bool = True,
    **kwargs,
) -> None

Applies lora specifically for VocabParallelEmbeddingWithLoRA.

Semantics

y += x @ lora_b_stacked

Parameters:

Name Type Description Default
y Tensor

Output tensor.

required
x Tensor

Input tensor.

required
lora_b_stacked Tensor

lora_b's weights.

required
add_inputs bool

Default to True.

True
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_lora_embedding(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_b_stacked: torch.Tensor,
    add_inputs: bool = True,
    **kwargs,
) -> None:
    """
    Applies lora  specifically for VocabParallelEmbeddingWithLoRA.

    Semantics:
        y += x @ lora_b_stacked

    Args:
        y (torch.Tensor): Output tensor.
        x (torch.Tensor): Input tensor.
        lora_b_stacked (torch.Tensor): lora_b's weights.
        add_inputs (bool): Default to True.
    """

    lora_expand(
        x.unsqueeze(dim=0),
        (lora_b_stacked,),
        y,
        *self.token_mapping_meta.meta_args(
            x.size(0), self.lora_config.specialize_active_lora
        ),
        offset_start=0,
        add_inputs=add_inputs,
    )

add_lora_fused_moe

add_lora_fused_moe(
    y: Tensor,
    x: Tensor,
    lora_a_stacked: tuple[Tensor, ...],
    lora_b_stacked: tuple[Tensor, ...],
    topk_weights: Tensor,
    sorted_token_ids: Tensor | None,
    expert_ids: Tensor,
    num_tokens_post_padded: Tensor | None,
    max_lora_rank: int,
    top_k_num: int,
    shrink_config,
    expand_config,
    adapter_enabled: Tensor,
    mul_routed_weight=False,
    fully_sharded: bool = False,
    offset: int = 0,
    token_lora_mapping: Tensor | None = None,
)

Performs a fused forward computation for LoRA of Mixture-of-Experts (MoE) layer.

Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_lora_fused_moe(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_a_stacked: tuple[torch.Tensor, ...],
    lora_b_stacked: tuple[torch.Tensor, ...],
    topk_weights: torch.Tensor,
    sorted_token_ids: torch.Tensor | None,
    expert_ids: torch.Tensor,
    num_tokens_post_padded: torch.Tensor | None,
    max_lora_rank: int,
    top_k_num: int,
    shrink_config,
    expand_config,
    adapter_enabled: torch.Tensor,
    mul_routed_weight=False,
    fully_sharded: bool = False,
    offset: int = 0,
    token_lora_mapping: torch.Tensor | None = None,
):
    """
    Performs a fused forward computation for LoRA of Mixture-of-Experts (MoE) layer.
    """
    (
        token_lora_mapping_meta,
        _,
        _,
        _,
        lora_ids,
        _,
        num_active_loras,
    ) = self.token_mapping_meta.meta_args(
        x.size(0), self.lora_config.specialize_active_lora
    )
    if token_lora_mapping is None:
        token_lora_mapping = token_lora_mapping_meta
    fused_moe_lora(
        y,
        x,
        lora_a_stacked,
        lora_b_stacked,
        topk_weights,
        sorted_token_ids,
        expert_ids,
        num_tokens_post_padded,
        token_lora_mapping,
        max_lora_rank,
        top_k_num,
        lora_ids,
        num_active_loras,
        adapter_enabled,
        shrink_config.get("BLOCK_SIZE_M", 64),
        shrink_config.get("BLOCK_SIZE_N", 64),
        shrink_config.get("BLOCK_SIZE_K", 32),
        shrink_config.get("GROUP_SIZE_M", 8),
        shrink_config.get("NUM_WARPS", 4),
        shrink_config.get("NUM_STAGES", 3),
        shrink_config.get("SPLIT_K", 1),
        expand_config.get("BLOCK_SIZE_M", 64),
        expand_config.get("BLOCK_SIZE_N", 64),
        expand_config.get("BLOCK_SIZE_K", 32),
        expand_config.get("GROUP_SIZE_M", 8),
        expand_config.get("NUM_WARPS", 4),
        expand_config.get("NUM_STAGES", 3),
        expand_config.get("SPLIT_K", 1),
        mul_routed_weight,
        fully_sharded,
        offset,
    )

add_lora_linear

add_lora_linear(
    y: Tensor,
    x: Tensor,
    lora_a_stacked: tuple[Tensor, ...],
    lora_b_stacked: tuple[Tensor, ...],
    scale: float,
    output_slices: tuple[int, ...],
    *,
    buffer: Tensor | None = None,
    **kwargs,
) -> None

Applicable to linear-related lora.

Semantics

for i in range(len(lora_a_stacked)): y[i] += ( x[i].unsqueeze(0) @ lora_a_stacked[indices[i], layer_idx, :, :] @ lora_b_stacked[indices[i], layer_idx, :, :] * scale ).squeeze(0)

Args: y (torch.Tensor): Output tensor. Will be changed in-place. x (torch.Tensor): Input tensor lora_a_stacked (tuple[torch.Tensor, ...]): lora_a's weight. lora_b_stacked (tuple[torch.Tensor, ...]): lora_b's weight. scale (float): Scaling factor. output_slices (tuple[int, ...]): Every slice's size. buffer (Optional[torch.Tensor]): Defaults to None.

Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_lora_linear(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_a_stacked: tuple[torch.Tensor, ...],
    lora_b_stacked: tuple[torch.Tensor, ...],
    scale: float,
    output_slices: tuple[int, ...],
    *,
    buffer: torch.Tensor | None = None,
    **kwargs,
) -> None:
    """
    Applicable to linear-related lora.

    Semantics:
        for i in range(len(lora_a_stacked)):
            y[i] += (
                x[i].unsqueeze(0)
                @ lora_a_stacked[indices[i], layer_idx, :, :]
                @ lora_b_stacked[indices[i], layer_idx, :, :]
                * scale
                ).squeeze(0)
    Args:
        y (torch.Tensor): Output tensor. Will be changed in-place.
        x (torch.Tensor): Input tensor
        lora_a_stacked (tuple[torch.Tensor, ...]): lora_a's weight.
        lora_b_stacked (tuple[torch.Tensor, ...]): lora_b's weight.
        scale (float): Scaling factor.
        output_slices (tuple[int, ...]): Every slice's size.
        buffer (Optional[torch.Tensor]): Defaults to None.
    """

    assert len(lora_a_stacked) == len(lora_b_stacked) == len(output_slices)

    assert buffer is None, (
        "To minimize overhead, the buffer should be created by "
        ".add_lora_linear() instead of being passed in."
    )
    r = lora_b_stacked[0].size(-1)
    # We set the buffer to be float32 by default, refer to:
    # https://github.com/triton-lang/triton/issues/1387
    # Note: buffer is zeroed inside the shrink op
    buffer = torch.empty(
        (len(output_slices), x.size(0), r), dtype=torch.float32, device=x.device
    )

    self.add_shrink(
        buffer,  # type: ignore
        x,
        lora_a_stacked,
        scale,
        **kwargs,
    )
    self.add_expand(
        y,
        buffer,  # type: ignore
        lora_b_stacked,
        output_slices,
        add_inputs=True,
        **kwargs,
    )

add_lora_logits

add_lora_logits(
    y: Tensor,
    x: Tensor,
    lora_a_stacked: Tensor,
    lora_b_stacked: Tensor,
    scale,
    *,
    buffer: Tensor | None = None,
    **kwargs,
) -> None

Applies lora specifically for LogitsProcessorWithLoRA.

Semantics

buffer = (x @ lora_a_stacked) * scale y += buffer @ lora_b_stacked

Parameters:

Name Type Description Default
y Tensor

Output tensor.

required
x Tensor

Input tensor.

required
lora_a_stacked Tensor

lora_a's weights.

required
lora_b_stacked Tensor

lora_b's weights.

required
scale float

Scaling factor.

required
buffer Optional[Tensor]

Default to None.

None
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_lora_logits(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_a_stacked: torch.Tensor,
    lora_b_stacked: torch.Tensor,
    scale,
    *,
    buffer: torch.Tensor | None = None,
    **kwargs,
) -> None:
    """
    Applies lora  specifically for LogitsProcessorWithLoRA.

    Semantics:
        buffer = (x @ lora_a_stacked) * scale
        y += buffer @ lora_b_stacked

    Args:
        y (torch.Tensor): Output tensor.
        x (torch.Tensor): Input tensor.
        lora_a_stacked (torch.Tensor): lora_a's weights.
        lora_b_stacked (torch.Tensor): lora_b's weights.
        scale (float): Scaling factor.
        buffer (Optional[torch.Tensor]): Default to None.
    """
    y_org = y
    y = y.view(-1, y.shape[-1])
    x = x.view(-1, x.shape[-1])
    r = lora_b_stacked.size(-1)

    assert buffer is None, (
        "To minimize overhead, the buffer should be created by "
        ".add_lora_linear() instead of being passed in."
    )
    # We set the buffer to be float32 by default, refer to:
    # https://github.com/triton-lang/triton/issues/1387
    # Note: buffer is zeroed inside the shrink op
    buffer = torch.empty((x.size(0), r), dtype=torch.float32, device=x.device)

    lora_shrink(
        x,
        [lora_a_stacked],
        buffer.unsqueeze(dim=0),
        *self.prompt_mapping_meta.meta_args(
            x.size(0), self.lora_config.specialize_active_lora
        ),
        scale,
    )

    lora_expand(
        buffer.unsqueeze(dim=0),
        [lora_b_stacked],
        y,
        *self.prompt_mapping_meta.meta_args(
            buffer.size(0), self.lora_config.specialize_active_lora
        ),
        add_inputs=True,
    )
    y = y.view_as(y_org)

add_shrink

add_shrink(
    y: Tensor,
    x: Tensor,
    lora_a_stacked: tuple[Tensor, ...],
    scale: float,
    **kwargs,
)

Performs GEMM for multiple slices of lora_a.

Semantics: for i in range(len(lora_a_stacked)): y[i] += (x @ lora_a_stacked[i]) * scale

Parameters:

Name Type Description Default
y Tensor

Output tensors

required
x Tensor

Input tensor

required
lora_a_stacked tuple[Tensor, ...]

lora_a's weights

required
scale float

Scaling factor for the operation

required
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def add_shrink(
    self,
    y: torch.Tensor,
    x: torch.Tensor,
    lora_a_stacked: tuple[torch.Tensor, ...],
    scale: float,
    **kwargs,
):
    """
    Performs GEMM  for multiple slices of lora_a.

    Semantics:
    for i in range(len(lora_a_stacked)):
        y[i] += (x @ lora_a_stacked[i]) * scale

    Args:
        y (torch.Tensor): Output tensors
        x (torch.Tensor): Input tensor
        lora_a_stacked (tuple[torch.Tensor, ...]): lora_a's weights
        scale (float): Scaling factor for the operation
    """

    x = x.view(-1, x.shape[-1])
    lora_shrink(
        x,
        lora_a_stacked,
        y,
        *self.token_mapping_meta.meta_args(
            x.size(0), self.lora_config.specialize_active_lora
        ),
        scale,
    )

moe_lora_align_block_size

moe_lora_align_block_size(
    topk_ids: Tensor,
    num_tokens: int,
    block_size: int,
    num_experts: int,
    max_loras: int,
    adapter_enabled: Tensor,
    expert_map: Tensor | None = None,
    pad_sorted_ids: bool = False,
    naive_block_assignment: bool = False,
) -> tuple[Tensor, Tensor, Tensor, Tensor]

Aligns tokens and experts into block-sized chunks for LoRA-based mixture-of-experts (MoE) execution.

Source code in vllm/lora/punica_wrapper/punica_gpu.py
def moe_lora_align_block_size(
    self,
    topk_ids: torch.Tensor,
    num_tokens: int,
    block_size: int,
    num_experts: int,
    max_loras: int,
    adapter_enabled: torch.Tensor,
    expert_map: torch.Tensor | None = None,
    pad_sorted_ids: bool = False,
    naive_block_assignment: bool = False,
) -> tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
    """
    Aligns tokens and experts into block-sized chunks for LoRA-based
    mixture-of-experts (MoE) execution.
    """
    (token_lora_mapping, _, _, _, lora_ids, _, _) = (
        self.token_mapping_meta.meta_args(
            num_tokens, self.lora_config.specialize_active_lora
        )
    )
    if naive_block_assignment:
        expert_ids = topk_ids.reshape(-1)
        sorted_ids = None
        num_tokens_post_pad = None
    else:
        max_num_tokens_padded = topk_ids.numel() + num_experts * (block_size - 1)
        if pad_sorted_ids:
            max_num_tokens_padded = round_up(max_num_tokens_padded, block_size)
        sorted_ids = torch.empty(
            (max_loras * max_num_tokens_padded,),
            dtype=torch.int32,
            device=topk_ids.device,
        )
        max_num_m_blocks = triton.cdiv(max_num_tokens_padded, block_size)
        # Expert ids must be set default to -1 to prevent a blank block
        expert_ids = torch.empty(
            (max_loras * max_num_m_blocks,),
            dtype=torch.int32,
            device=topk_ids.device,
        )
        num_tokens_post_pad = torch.empty(
            (max_loras), dtype=torch.int32, device=topk_ids.device
        )

        ops.moe_lora_align_block_size(
            topk_ids,
            token_lora_mapping,
            num_experts,
            block_size,
            max_loras,
            max_num_tokens_padded,
            max_num_m_blocks,
            sorted_ids,
            expert_ids,
            num_tokens_post_pad,
            adapter_enabled,
            lora_ids,
        )
        if expert_map is not None:
            expert_ids = expert_map[expert_ids]

    return None, sorted_ids, expert_ids, num_tokens_post_pad

update_metadata

update_metadata(
    mapping: LoRAMapping,
    lora_index_to_id: list[int | None],
    max_loras: int,
    vocab_size: int,
    **kwargs,
)
Source code in vllm/lora/punica_wrapper/punica_gpu.py
def update_metadata(
    self,
    mapping: LoRAMapping,
    lora_index_to_id: list[int | None],
    max_loras: int,
    vocab_size: int,
    **kwargs,
):
    self.is_prefill = mapping.is_prefill
    self._update_base_metadata(mapping, lora_index_to_id, max_loras, vocab_size)

    # Prepare cuda kernel metadata tensors
    self.token_mapping_meta.prepare_tensors(self.token_lora_indices)
    self.prompt_mapping_meta.prepare_tensors(self.sampler_indices)