vllm/tests/kernels/moe/test_moe_permute_unpermute.py
Harry Mellor 8fcaaf6a16
Update Optional[x] -> x | None and Union[x, y] to x | y (#26633)
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
2025-10-12 09:51:31 -07:00

306 lines
11 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Tests for the MOE permute/unpermute kernel
Run `pytest tests/kernels/test_moe_permute_unpermute.py`.
"""
import numpy as np
import pytest
import torch
from vllm.model_executor.layers.fused_moe.fused_moe import fused_topk
from vllm.model_executor.layers.fused_moe.layer import determine_expert_map
from vllm.model_executor.layers.fused_moe.moe_permute_unpermute import (
moe_permute,
moe_permute_unpermute_supported,
moe_unpermute,
)
from vllm.platforms import current_platform
NUM_EXPERTS = [16, 64, 256]
TOP_KS = [2, 6, 8]
EP_SIZE = [1, 4, 16]
current_platform.seed_everything(0)
def torch_permute(
hidden_states: torch.Tensor,
topk_ids: torch.Tensor,
# token_expert_indices: torch.Tensor,
topk: int,
n_expert: int,
n_local_expert: int,
start_expert: int,
expert_map: torch.Tensor | None = None,
align_block_size: int | None = None,
fill_invalid_expert: int = -1,
) -> list[torch.Tensor]:
n_token, n_hidden = hidden_states.shape[0], hidden_states.shape[1]
if expert_map is not None:
is_local_expert = expert_map[topk_ids] != -1
not_local_expert = expert_map[topk_ids] == -1
topk_ids = is_local_expert * (topk_ids - start_expert) + not_local_expert * (
topk_ids + n_expert
)
token_expert_indices = torch.arange(
0, n_token * topk, dtype=torch.int32, device=hidden_states.device
).reshape((n_token, topk))
sorted_topk_ids, sorted_indices = torch.sort(topk_ids.flatten(), stable=True)
dst_row_id2src_row_id_map = token_expert_indices.flatten()[sorted_indices]
expert_first_token_offset = torch.zeros(
n_local_expert + 1, dtype=torch.int64, device="cuda"
)
idx = 0
for i in range(0, n_local_expert):
cnt = 0
while idx < sorted_topk_ids.numel() and sorted_topk_ids[idx] == i:
cnt += 1
idx += 1
expert_first_token_offset[i + 1] = expert_first_token_offset[i] + cnt
_, src2dst_idx = torch.sort(dst_row_id2src_row_id_map)
valid_row_idx = []
if align_block_size is None:
permuted_hidden_states = hidden_states[dst_row_id2src_row_id_map // topk, ...]
permuted_row_size = permuted_hidden_states.shape[0]
m_indices = torch.empty(
permuted_row_size, device="cuda", dtype=torch.int32
).fill_(fill_invalid_expert)
for i in range(1, n_local_expert + 1):
first_token_offset = expert_first_token_offset[i - 1]
last_token_offset = expert_first_token_offset[i]
m_indices[first_token_offset:last_token_offset] = i - 1
src_row_id2dst_row_id_map = torch.arange(
0, n_token * topk, device="cuda", dtype=torch.int32
)[src2dst_idx].reshape((n_token, topk))
valid_row_idx += [i for i in range(expert_first_token_offset[-1])]
dst_row_id2src_row_id_map[expert_first_token_offset[-1] :] = n_token * topk
return [
permuted_hidden_states,
expert_first_token_offset,
src_row_id2dst_row_id_map,
dst_row_id2src_row_id_map,
m_indices,
valid_row_idx,
]
else:
permuted_row_size = (
(topk * n_token + n_expert * (align_block_size - 1) + align_block_size - 1)
// align_block_size
* align_block_size
)
permuted_idx = torch.full(
(permuted_row_size,),
n_token * topk,
dtype=torch.int32,
device=hidden_states.device,
)
permuted_hidden_states = torch.empty(
(permuted_row_size, n_hidden), device="cuda", dtype=hidden_states.dtype
)
align_src_row_id2dst_row_id = torch.empty(
n_token * topk, device="cuda", dtype=torch.int32
)
align_expert_first_token_offset = torch.zeros_like(expert_first_token_offset)
m_indices = torch.empty(
permuted_row_size, device="cuda", dtype=torch.int32
).fill_(fill_invalid_expert)
# get align_permuted_hidden_states,
# valid row_idx and align_expert_first_token_offset
for i in range(1, n_local_expert + 1):
first_token_offset = expert_first_token_offset[i - 1]
last_token_offset = expert_first_token_offset[i]
n_token_in_expert = last_token_offset - first_token_offset
align_expert_first_token_offset[i] = (
align_expert_first_token_offset[i - 1]
+ (n_token_in_expert + align_block_size - 1)
// align_block_size
* align_block_size
)
align_first_token_offset = align_expert_first_token_offset[i - 1]
align_last_token_offset = align_expert_first_token_offset[i]
dst_row_id2src_row_id_in_expert = dst_row_id2src_row_id_map[
first_token_offset : first_token_offset + n_token_in_expert
]
# store token in current expert with align_first_token_offset
permuted_hidden_states[
align_first_token_offset : align_first_token_offset + n_token_in_expert,
...,
] = hidden_states[dst_row_id2src_row_id_in_expert // topk, ...]
permuted_idx[
align_first_token_offset : align_first_token_offset + n_token_in_expert
] = dst_row_id2src_row_id_in_expert
# set current expert m_indices
m_indices[align_first_token_offset:align_last_token_offset] = i - 1
valid_row_idx += [
i
for i in range(
align_first_token_offset,
align_first_token_offset + n_token_in_expert,
)
]
# get align_src_row_id2dst_row_id
for i in range(n_token * topk):
eid = sorted_topk_ids[i]
if eid >= n_local_expert:
# check token not in local expert
align_src_row_id2dst_row_id[i] = align_expert_first_token_offset[-1]
continue
first_token_offset = expert_first_token_offset[eid]
align_first_token_offset = align_expert_first_token_offset[eid]
token_offset = i - first_token_offset
align_src_row_id2dst_row_id[i] = align_first_token_offset + token_offset
align_src_row_id2dst_row_id = align_src_row_id2dst_row_id[src2dst_idx].reshape(
(n_token, topk)
)
return [
permuted_hidden_states,
align_expert_first_token_offset,
align_src_row_id2dst_row_id,
permuted_idx,
m_indices,
valid_row_idx,
]
def torch_unpermute(
permuted_hidden_states: torch.Tensor,
topk_weights: torch.Tensor,
topk_ids: torch.Tensor,
token_expert_indices: torch.Tensor,
src_row_id2dst_row_id_map: torch.Tensor,
valid_row_idx: torch.Tensor,
topk: int,
n_expert: int,
) -> torch.Tensor:
# ignore invalid row
n_hidden = permuted_hidden_states.shape[1]
mask = torch.zeros(permuted_hidden_states.shape[0], dtype=bool, device="cuda")
mask[valid_row_idx] = True
permuted_hidden_states[~mask] = 0
permuted_hidden_states = permuted_hidden_states[
src_row_id2dst_row_id_map.flatten(), ...
]
permuted_hidden_states = permuted_hidden_states.view(-1, topk, n_hidden)
output = (
(permuted_hidden_states * topk_weights.unsqueeze(2))
.sum(1)
.to(permuted_hidden_states.dtype)
)
return output
@pytest.mark.parametrize("n_token", [1, 33, 1024, 5000])
@pytest.mark.parametrize("n_hidden", [2048, 7168])
@pytest.mark.parametrize("n_expert", NUM_EXPERTS)
@pytest.mark.parametrize("topk", TOP_KS)
@pytest.mark.parametrize("dtype", [torch.bfloat16])
@pytest.mark.parametrize("ep_size", EP_SIZE)
@pytest.mark.parametrize("align_block_size", [None, 128])
def test_moe_permute_unpermute(
n_token: int,
n_hidden: int,
topk: int,
n_expert: int,
ep_size: int,
dtype: torch.dtype,
align_block_size: int | None,
):
if not moe_permute_unpermute_supported():
pytest.skip("moe_permute_unpermute is not supported on this platform.")
fill_invalid_expert = 0
ep_rank = np.random.randint(0, ep_size)
expert_map = None
n_local_expert = n_expert
if ep_size != 1:
n_local_expert, expert_map = determine_expert_map(ep_size, ep_rank, n_expert)
expert_map = expert_map.cuda()
start_expert = n_local_expert * ep_rank
current_platform.seed_everything(0)
hidden_states = torch.randn((n_token, n_hidden), device="cuda").to(dtype)
gating_output = torch.randn((n_token, n_expert), device="cuda").to(dtype)
topk_weights, topk_ids, token_expert_indices = fused_topk(
hidden_states, gating_output, topk, False
)
(
gold_permuted_hidden_states,
gold_expert_first_token_offset,
gold_inv_permuted_idx,
gold_permuted_idx,
gold_m_indices,
valid_row_idx,
) = torch_permute(
hidden_states,
topk_ids,
# token_expert_indices,
topk,
n_expert,
n_local_expert,
start_expert,
expert_map=expert_map,
align_block_size=align_block_size,
fill_invalid_expert=fill_invalid_expert,
)
(
permuted_hidden_states,
_,
expert_first_token_offset,
inv_permuted_idx,
m_indices,
) = moe_permute(
hidden_states=hidden_states,
a1q_scale=None,
topk_ids=topk_ids,
n_expert=n_expert,
n_local_expert=n_local_expert,
expert_map=expert_map,
align_block_size=align_block_size,
fill_invalid_expert=fill_invalid_expert,
)
# check expert_first_token_offset
torch.testing.assert_close(
gold_expert_first_token_offset, expert_first_token_offset, atol=0, rtol=0
)
# check src_row_id2dst_row_id_map
torch.testing.assert_close(
gold_inv_permuted_idx.flatten(), inv_permuted_idx, atol=0, rtol=0
)
# check mindice
# current kernel usage assumes deepgemm requires align_block_size
# when it's not provided then we don't compute m_indices (for cutlass)
if align_block_size is not None:
torch.testing.assert_close(gold_m_indices, m_indices, atol=0, rtol=0)
# check permuted_hidden_states, only valid token
torch.testing.assert_close(
gold_permuted_hidden_states[valid_row_idx],
permuted_hidden_states[valid_row_idx],
atol=0,
rtol=0,
)
# add a random tensor to simulate group gemm
result0 = 0.5 * permuted_hidden_states + torch.randn_like(permuted_hidden_states)
result4 = torch.empty_like(hidden_states)
moe_unpermute(
result4, result0, topk_weights, inv_permuted_idx, expert_first_token_offset
)
gold4 = torch_unpermute(
result0,
topk_weights,
topk_ids,
token_expert_indices,
inv_permuted_idx,
valid_row_idx,
topk,
n_local_expert,
)
# check unpermuted hidden
torch.testing.assert_close(result4, gold4, atol=2e-2, rtol=0)