Wentao Ye a8141fa649
[Refactor] Remove VLLM_DEEPEP_LOW_LATENCY_ALLOW_NVLINK (#27750)
Signed-off-by: yewentao256 <zhyanwentao@126.com>
2025-10-30 15:32:39 -04:00

491 lines
16 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from typing import Any
import torch
import torch.distributed as dist
import vllm.envs as envs
from vllm.distributed import get_dp_group, get_ep_group
from vllm.forward_context import get_forward_context
from vllm.logger import init_logger
from vllm.utils.flashinfer import has_flashinfer_all2all
from vllm.utils.import_utils import has_deep_ep, has_pplx
from .base_device_communicator import All2AllManagerBase, Cache
if has_flashinfer_all2all():
from flashinfer.comm import Mapping # type: ignore[import-not-found]
from flashinfer.comm.mnnvl import MnnvlConfig # type: ignore[import-not-found]
from flashinfer.comm.trtllm_alltoall import (
MnnvlMoe, # type: ignore[import-not-found]
)
logger = init_logger(__name__)
class NaiveAll2AllManager(All2AllManagerBase):
"""
A naive implementation of all2all communication.
It uses all-reduce under the hood, which is not
efficient at all. The main purpose is for testing and
debugging.
"""
def __init__(self, cpu_group):
super().__init__(cpu_group)
def naive_multicast(
self,
x: torch.Tensor,
cu_tokens_across_sp_cpu: torch.Tensor,
is_sequence_parallel: bool,
) -> torch.Tensor:
assert len(x.shape) == 2
buffer = torch.empty(
(cu_tokens_across_sp_cpu[-1], x.size(1)), device=x.device, dtype=x.dtype
)
rank = self.rank if is_sequence_parallel else self.dp_rank
world_size = self.world_size if is_sequence_parallel else self.dp_world_size
start = 0 if rank == 0 else cu_tokens_across_sp_cpu[rank - 1]
end = cu_tokens_across_sp_cpu[rank]
buffer[start:end, :].copy_(x)
for idx in range(world_size):
start = 0 if idx == 0 else cu_tokens_across_sp_cpu[idx - 1]
end = cu_tokens_across_sp_cpu[idx]
get_ep_group().broadcast(buffer[start:end, :], idx)
return buffer
def dispatch(
self,
hidden_states: torch.Tensor,
router_logits: torch.Tensor,
is_sequence_parallel: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
sp_size = self.tp_group.world_size if is_sequence_parallel else 1
dp_metadata = get_forward_context().dp_metadata
assert dp_metadata is not None
cu_tokens_across_sp_cpu = dp_metadata.cu_tokens_across_sp(sp_size)
hidden_states = self.naive_multicast(
hidden_states, cu_tokens_across_sp_cpu, is_sequence_parallel
)
router_logits = self.naive_multicast(
router_logits, cu_tokens_across_sp_cpu, is_sequence_parallel
)
return hidden_states, router_logits
def combine(
self, hidden_states: torch.Tensor, is_sequence_parallel: bool = False
) -> torch.Tensor:
ep_rank = self.rank if is_sequence_parallel else self.dp_rank
dp_metadata = get_forward_context().dp_metadata
assert dp_metadata is not None
sp_size = self.tp_group.world_size if is_sequence_parallel else 1
cu_tokens_across_sp_cpu = dp_metadata.cu_tokens_across_sp(sp_size)
start = 0 if ep_rank == 0 else cu_tokens_across_sp_cpu[ep_rank - 1]
end = cu_tokens_across_sp_cpu[ep_rank]
all_hidden_states = get_ep_group().all_reduce(hidden_states)
hidden_states = all_hidden_states[start:end, :]
return hidden_states
def destroy(self):
pass
class AgRsAll2AllManager(All2AllManagerBase):
"""
An implementation of all2all communication based on
all-gather (dispatch) and reduce-scatter (combine).
"""
def __init__(self, cpu_group):
super().__init__(cpu_group)
def dispatch(
self,
hidden_states: torch.Tensor,
router_logits: torch.Tensor,
is_sequence_parallel: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
"""
Gather hidden_states and router_logits from all dp ranks.
"""
dp_metadata = get_forward_context().dp_metadata
assert dp_metadata is not None
sizes = dp_metadata.get_chunk_sizes_across_dp_rank()
assert sizes is not None
dist_group = get_ep_group() if is_sequence_parallel else get_dp_group()
assert sizes[dist_group.rank_in_group] == hidden_states.shape[0]
hidden_states, router_logits = dist_group.all_gatherv(
[hidden_states, router_logits],
dim=0,
sizes=sizes,
)
return hidden_states, router_logits
def combine(
self, hidden_states: torch.Tensor, is_sequence_parallel: bool = False
) -> torch.Tensor:
"""
Reduce-scatter hidden_states across all dp ranks.
"""
dp_metadata = get_forward_context().dp_metadata
assert dp_metadata is not None
sizes = dp_metadata.get_chunk_sizes_across_dp_rank()
assert sizes is not None
dist_group = get_ep_group() if is_sequence_parallel else get_dp_group()
hidden_states = dist_group.reduce_scatterv(hidden_states, dim=0, sizes=sizes)
return hidden_states
def destroy(self):
pass
class PPLXAll2AllManager(All2AllManagerBase):
"""
All2All communication based on PPLX kernels.
"""
def __init__(self, cpu_group):
assert has_pplx(), (
"pplx_kernels not found. Please follow https://github.com/vllm-project/vllm/blob/main/tools/ep_kernels/README.md"
" to install pplx_kernels."
)
super().__init__(cpu_group)
if self.internode:
# inter-node communication needs nvshmem,
# intra-node communication uses p2p mapping directly
from pplx_kernels.nvshmem import ( # type: ignore[import-not-found]
nvshmem_alloc_empty_unique_id,
nvshmem_get_unique_id,
nvshmem_init,
)
logger.debug(
"Initialize NVSHMEM for pplx_kernels: rank=%d, world size=%d",
self.rank,
self.world_size,
)
uid = (
nvshmem_get_unique_id()
if self.rank == 0
else nvshmem_alloc_empty_unique_id()
)
dist.broadcast(
uid,
src=dist.get_process_group_ranks(self.cpu_group)[0],
group=self.cpu_group,
)
logger.debug("PPLX NVSHMEM UID = %s", uid)
nvshmem_init(uid, self.rank, self.world_size)
self.handle_cache = Cache()
def get_handle(self, kwargs):
import pplx_kernels as pplx # type: ignore[import-not-found]
return self.handle_cache.get_or_create(
kwargs,
pplx.AllToAll.internode if self.internode else pplx.AllToAll.intranode,
)
def dispatch(
self,
hidden_states: torch.Tensor,
router_logits: torch.Tensor,
is_sequence_parallel: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
raise NotImplementedError
def combine(
self, hidden_states: torch.Tensor, is_sequence_parallel: bool = False
) -> torch.Tensor:
raise NotImplementedError
def destroy(self):
with self.handle_cache._lock:
for _, handle in self.handle_cache._cache.items():
handle.destroy()
if self.internode:
from pplx_kernels.nvshmem import (
nvshmem_finalize, # type: ignore[import-not-found]
)
logger.debug("PPLX NVSHMEM finalize")
nvshmem_finalize()
class DeepEPAll2AllManagerBase(All2AllManagerBase):
"""
All2All communication based on DeepEP High-Throughput kernels.
"""
def __init__(self, cpu_group):
assert has_deep_ep(), (
"DeepEP kernels not found. Please follow https://github.com/vllm-project/vllm/blob/main/tools/ep_kernels/README.md"
" to install DeepEP kernels."
) # noqa
super().__init__(cpu_group)
self.handle_cache = Cache()
# This is the DeepEP default. Stick to it till we can establish
# reasonable defaults based on profiling.
self.num_sms = 20
def get_handle(self, kwargs):
raise NotImplementedError
def dispatch(
self,
hidden_states: torch.Tensor,
router_logits: torch.Tensor,
is_sequence_parallel: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
raise NotImplementedError
def combine(
self, hidden_states: torch.Tensor, is_sequence_parallel: bool = False
) -> torch.Tensor:
raise NotImplementedError
def destroy(self):
pass
class DeepEPHTAll2AllManager(DeepEPAll2AllManagerBase):
"""
All2All communication based on DeepEP High-Throughput kernels.
"""
def __init__(self, cpu_group):
super().__init__(cpu_group)
def _make_all2all_kwargs(self) -> dict[Any, Any]:
# Defaults for internode and intranode are taken from DeepEP tests.
num_nvl_bytes = envs.VLLM_DEEPEP_BUFFER_SIZE_MB * 1024 * 1024
num_rdma_bytes = None
num_qps_per_rank = None
if self.internode and not envs.VLLM_DEEPEP_HIGH_THROUGHPUT_FORCE_INTRA_NODE:
num_rdma_bytes = envs.VLLM_DEEPEP_BUFFER_SIZE_MB * 1024 * 1024
num_qps_per_rank = self.num_sms // 2
else:
num_rdma_bytes = 0
num_qps_per_rank = 1
assert num_rdma_bytes is not None
assert num_qps_per_rank is not None
return dict(
group=self.cpu_group,
num_nvl_bytes=num_nvl_bytes,
num_rdma_bytes=num_rdma_bytes,
low_latency_mode=False,
num_qps_per_rank=num_qps_per_rank,
)
def get_handle(self, kwargs):
assert len(kwargs) == 0, (
"DeepEPHTAll2AllManager expects no arguments. All the required "
"args are computed in the Manager itself."
)
import deep_ep # type: ignore[import-not-found]
buffer_kwargs = self._make_all2all_kwargs()
logger.debug("DeepEP all2all args %s", buffer_kwargs)
handle: deep_ep.Buffer = self.handle_cache.get_or_create(
buffer_kwargs, deep_ep.Buffer
)
return handle
def set_num_sms(self, num_sms: int):
import deep_ep # type: ignore[import-not-found]
# Right now the buffers are sized for only what the kernels were
# created with. So we can only reduce the number of SMS used
# but not increase it.
if num_sms > self.num_sms:
num_sms = self.num_sms
deep_ep.Buffer.set_num_sms(num_sms)
class DeepEPLLAll2AllManager(DeepEPAll2AllManagerBase):
"""
All2All communication based on DeepEP Low-Latency kernels.
"""
def __init__(self, cpu_group):
super().__init__(cpu_group)
def _make_all2all_kwargs(
self,
max_num_tokens_per_dp_rank: int,
token_hidden_size: int,
num_ep_ranks: int,
num_global_experts: int,
num_local_experts: int,
) -> dict[Any, Any]:
"""
max_num_tokens_per_dp_rank : the maximum number of tokens a DP rank
can dispatch all the ranks must hold the same value.
token_hidden_size: the hidden dimension of each token.
num_ep_ranks: the number of EP group ranks.
num_global_experts: Number of experts in the model.
num_local_experts: Number of experts in an EP rank.
"""
import deep_ep # type: ignore[import-not-found]
# Defaults for internode and intranode are taken from DeepEP tests.
num_nvl_bytes = envs.VLLM_DEEPEP_BUFFER_SIZE_MB * 1024 * 1024
num_qps_per_rank = num_local_experts
num_rdma_bytes = deep_ep.Buffer.get_low_latency_rdma_size_hint(
num_max_dispatch_tokens_per_rank=max_num_tokens_per_dp_rank,
hidden=token_hidden_size,
num_ranks=num_ep_ranks,
num_experts=num_global_experts,
)
assert num_rdma_bytes is not None
return dict(
group=self.cpu_group,
num_nvl_bytes=num_nvl_bytes,
num_rdma_bytes=num_rdma_bytes,
low_latency_mode=True,
num_qps_per_rank=num_qps_per_rank,
allow_nvlink_for_low_latency_mode=True,
allow_mnnvl=envs.VLLM_DEEPEP_LOW_LATENCY_USE_MNNVL,
)
def get_handle(self, kwargs):
"""
The kwargs for DeepEPLLAll2AllManager is dictated by
_make_all2all_kwargs.
"""
import deep_ep # type: ignore[import-not-found]
buffer_kwargs = self._make_all2all_kwargs(**kwargs)
logger.debug("DeepEP all2all args %s", buffer_kwargs)
handle: deep_ep.Buffer = self.handle_cache.get_or_create(
buffer_kwargs, deep_ep.Buffer
)
return handle
# DeepEP LL uses RDMA so no SMs are used for communication
def max_sms_used(self) -> int | None:
return 0
class FlashInferAllToAllManager(All2AllManagerBase):
"""
All2All communication based on flashinfer kernels.
"""
# This type lint could be removed after all of the work in
# https://github.com/vllm-project/vllm/issues/26533 done.
rank: int
world_size: int
def __init__(self, cpu_group):
assert has_flashinfer_all2all(), (
"flashinfer all2all module not found. Please install/check flashinfer"
) # noqa
super().__init__(cpu_group)
logger.debug(
"Initialize for flashinfer All2All rank=%d, world size=%d",
self.rank,
self.world_size,
)
self.initialized = False
self.alltoall_info = None
def initialize(
self,
world_size: int,
rank: int,
gpus_per_node: int,
):
"""Initialize workspace"""
if self.initialized:
return
self.cleanup()
logger.debug("making map: rank=%d, world size=%d", rank, world_size)
self.mapping = Mapping(
world_size,
rank,
gpus_per_node,
tp_size=world_size,
)
from vllm.distributed.device_communicators.mnnvl_compat import (
CustomCommunicator,
)
dp_config = MnnvlConfig(
comm_backend=CustomCommunicator(get_dp_group().cpu_group),
fabric_page_size=1 << 29, # 512MB
allocation_granularity=0, # Auto-detect
)
self.workspace_tensor = MnnvlMoe.get_moe_workspaces(self.mapping, dp_config)
self.prepare_workspace_tensor = MnnvlMoe.get_moe_prepare_workspace(
self.mapping, dp_config
)
self.world_size = world_size
self.rank = rank
self.gpus_per_node = gpus_per_node
self.initialized = True
logger.info(
"FlashInfer All2All initialized for rank %s, size %s", rank, world_size
)
def ensure_alltoall_workspace_initialized(self):
"""Ensure workspace is initialized"""
if not has_flashinfer_all2all():
return False
if self.world_size <= 1:
return False
if not self.initialized:
self.initialize(
world_size=self.world_size,
rank=self.rank,
gpus_per_node=torch.cuda.device_count,
)
return self.initialized
def get_handle(self, kwargs):
return self
def cleanup(self):
"""Clean up workspace"""
if (
self.initialized
and self.workspace_tensor is not None
and self.prepare_workspace_tensor is not None
):
try:
del self.workspace_tensor
del self.prepare_workspace_tensor
except Exception as e:
logger.warning("Failed to cleanup FlashInfer workspace: %s", e)
finally:
self.workspace_tensor = None
self.prepare_workspace_tensor = None
self.mapping = None
self.initialized = False