xc-llm-ascend/vllm_ascend/distributed/utils.py

from typing import Optional

import torch
import torch.distributed as dist
from vllm.distributed.parallel_state import GroupCoordinator, get_dp_group
from vllm.forward_context import get_forward_context

from vllm_ascend.distributed.parallel_state import get_fc3_quant_x_group


def fc3_all_gather_and_maybe_unpad_impl(x: torch.Tensor, ) -> torch.Tensor:
    try:
        forward_context = get_forward_context()
    except AssertionError:
        return x
    x = get_fc3_quant_x_group().all_gather(x, 0)
    dp_metadata = forward_context.dp_metadata
    if dp_metadata is None:
        pad_size = forward_context.pad_size
        if pad_size > 0:
            x = x[:-pad_size]
    else:
        # unpad
        num_tokens_across_dp_cpu = dp_metadata.num_tokens_across_dp_cpu
        result = torch.empty((num_tokens_across_dp_cpu.sum(), *x.shape[1:]),
                             device=x.device,
                             dtype=x.dtype)
        dp_size = get_dp_group().world_size
        x = x.view(dp_size, forward_context.padded_length, *x.shape[1:])
        offset = 0
        for idx in range(dp_size):
            num_tokens_dp = num_tokens_across_dp_cpu[idx]
            result[offset:offset + num_tokens_dp] = x[idx, :num_tokens_dp]
            offset += num_tokens_dp
        x = result

    return x


def all_gather_async(input: torch.Tensor,
                     group: GroupCoordinator,
                     output: Optional[torch.Tensor] = None,
                     async_op: bool = True):
    if group.world_size == 1:
        return input, None
    if output is None:
        input_size = input.size()
        output_size = (input_size[0] * group.world_size, ) + input_size[1:]
        output = torch.empty(output_size,
                             dtype=input.dtype,
                             device=input.device)
    return output, dist.all_gather_into_tensor(output,
                                               input,
                                               group=group.device_group,
                                               async_op=async_op)