Files
vLLM/vllm/model_executor/layers/mamba/mamba_utils.py
T

56 lines
1.7 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from vllm.distributed import divide
def extra_groups_for_head_shards(ngroups: int, tp_size: int):
"""Compute the increase in group numbers to account for
replication in order to accompany the head shards."""
# in the case ngoups % tp_size == 0, this will be zero
if ngroups % tp_size == 0:
return 0
# for n_groups == 1, this is exactly tp_size - n_groups
return tp_size - ngroups
def get_mamba_state_shape(
intermediate_size: int,
tp_world_size: int,
n_groups: int,
num_heads: int,
head_dim: int,
state_size: int,
conv_kernel: int,
use_v1: bool = True,
) -> tuple[tuple[int, int], tuple[int, int, int]]:
""" Get the shape of mamba state."""
# if n_groups is not divisible by world_size, need to extend the shards
# to ensure all groups needed by a head is sharded along with it
n_groups = (n_groups +
extra_groups_for_head_shards(n_groups, tp_world_size))
# - heads and n_groups are TP-ed
conv_dim = (intermediate_size + 2 * n_groups * state_size)
# contiguous along 'dim' axis
conv_state_shape = (
conv_kernel - 1,
divide(conv_dim, tp_world_size),
)
if not use_v1:
conv_state_shape = (conv_state_shape[1], conv_state_shape[0])
# These are not TP-ed as they depend on A, dt_bias, D
# - they are typically small
# e.g., (h_heads, head_dim, state_size) = (128, 64, 128)
temporal_state_shape = (
divide(num_heads, tp_world_size),
head_dim,
state_size,
)
return conv_state_shape, temporal_state_shape