sglang0.4.5.post1/python/sglang/srt/layers/dp_attention.py

263 lines
7.4 KiB
Python

from __future__ import annotations
import functools
import logging
from contextlib import contextmanager
from typing import TYPE_CHECKING, List
import torch
import triton
import triton.language as tl
from sglang.srt.distributed import (
GroupCoordinator,
get_tensor_model_parallel_world_size,
get_tp_group,
tensor_model_parallel_all_reduce,
)
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from sglang.srt.model_executor.forward_batch_info import ForwardBatch
_ATTN_TP_GROUP = None
_ATTN_TP_RANK = None
_ATTN_TP_SIZE = None
_DP_RANK = None
_DP_SIZE = None
def compute_dp_attention_world_info(enable_dp_attention, tp_rank, tp_size, dp_size):
if not enable_dp_attention:
return tp_rank, tp_size, 0
attn_tp_size = tp_size // dp_size
dp_rank = tp_rank // attn_tp_size
attn_tp_rank = tp_rank % attn_tp_size
return attn_tp_rank, attn_tp_size, dp_rank
def initialize_dp_attention(
enable_dp_attention: bool,
tp_rank: int,
tp_size: int,
dp_size: int,
):
global _ATTN_TP_GROUP, _ATTN_TP_RANK, _ATTN_TP_SIZE, _DP_RANK, _DP_SIZE
from sglang.srt.layers.sampler import SYNC_TOKEN_IDS_ACROSS_TP
_ATTN_TP_RANK, _ATTN_TP_SIZE, _DP_RANK = compute_dp_attention_world_info(
enable_dp_attention, tp_rank, tp_size, dp_size
)
if enable_dp_attention:
_DP_SIZE = dp_size
else:
_DP_SIZE = 1
tp_group = get_tp_group()
_ATTN_TP_GROUP = GroupCoordinator(
[
list(range(head, head + _ATTN_TP_SIZE))
for head in range(0, tp_size, _ATTN_TP_SIZE)
],
tp_group.local_rank,
torch.distributed.get_backend(tp_group.device_group),
SYNC_TOKEN_IDS_ACROSS_TP,
False,
False,
False,
False,
group_name="attention_tp",
)
def get_attention_tp_group():
assert _ATTN_TP_GROUP is not None, "dp attention not initialized!"
return _ATTN_TP_GROUP
def get_attention_tp_rank():
assert _ATTN_TP_RANK is not None, "dp attention not initialized!"
return _ATTN_TP_RANK
def get_attention_tp_size():
assert _ATTN_TP_SIZE is not None, "dp attention not initialized!"
return _ATTN_TP_SIZE
def get_attention_dp_rank():
assert _DP_RANK is not None, "dp attention not initialized!"
return _DP_RANK
def get_attention_dp_size():
assert _DP_SIZE is not None, "dp attention not initialized!"
return _DP_SIZE
@contextmanager
def disable_dp_size():
"""Patch the tp group temporarily until this function ends.
This method is for draft workers of speculative decoding to run draft model
with different tp degree from that of target model workers.
Args:
tp_group (GroupCoordinator): the tp group coordinator
"""
global _DP_SIZE
assert _DP_SIZE is not None, "dp attention not initialized!"
old_dp_size = _DP_SIZE
_DP_SIZE = 1
try:
yield
finally:
_DP_SIZE = old_dp_size
def get_dp_local_info(forward_batch: ForwardBatch):
dp_rank = get_attention_dp_rank()
if forward_batch.dp_local_start_pos is None:
cumtokens = torch.cumsum(forward_batch.global_num_tokens_gpu, dim=0)
if dp_rank == 0:
local_start_pos = torch.zeros_like(cumtokens[0])
else:
local_start_pos = cumtokens[dp_rank - 1]
local_num_tokens = forward_batch.global_num_tokens_gpu[dp_rank]
forward_batch.dp_local_start_pos = local_start_pos
forward_batch.dp_local_num_tokens = local_num_tokens
return forward_batch.dp_local_start_pos, forward_batch.dp_local_num_tokens
@triton.jit
def memcpy_triton_kernel(
dst_ptr,
src_ptr,
offset_ptr,
sz_ptr,
offset_src,
chunk_size, # multiplied for offset and sz
BLOCK_SIZE: tl.constexpr,
):
pid = tl.program_id(axis=0).to(tl.int64)
offset = tl.load(offset_ptr).to(tl.int64) * chunk_size
sz = tl.load(sz_ptr).to(tl.int64) * chunk_size
start_index = pid * BLOCK_SIZE
offs = tl.arange(0, BLOCK_SIZE)
mask = start_index + offs < sz
if offset_src:
data = tl.load(src_ptr + offset + start_index + offs, mask=mask)
tl.store(dst_ptr + start_index + offs, data, mask=mask)
else:
data = tl.load(src_ptr + start_index + offs, mask=mask)
tl.store(dst_ptr + offset + start_index + offs, data, mask=mask)
def prod(x):
return functools.reduce(lambda a, b: a * b, x, 1)
def memcpy_triton(dst, src, dim, offset, sz, offset_src):
max_size = min(src.numel(), dst.numel())
assert dim == 0, "dim != 0 unsupported"
assert src.shape[1:] == dst.shape[1:], "src and dst must have same shape"
chunk_size = prod(src.shape[1:])
BLOCK_SIZE = 8192
grid = (triton.cdiv(max_size, BLOCK_SIZE),)
memcpy_triton_kernel[grid](dst, src, offset, sz, offset_src, chunk_size, BLOCK_SIZE)
def _dp_gather(
global_tokens: torch.Tensor,
local_tokens: torch.Tensor,
forward_batch: ForwardBatch,
is_partial: bool,
):
local_start_pos, local_num_tokens = get_dp_local_info(forward_batch)
global_tokens.fill_(0)
assert local_tokens.is_contiguous()
assert global_tokens.is_contiguous()
if local_tokens.shape[0] > 0 and (is_partial or get_attention_tp_rank() == 0):
assert (
global_tokens.untyped_storage().data_ptr()
!= local_tokens.untyped_storage().data_ptr()
), "aliasing between global_tokens and local_tokens not allowed"
memcpy_triton(
global_tokens, local_tokens, 0, local_start_pos, local_num_tokens, False
)
# Input IDs are in int 32. We should use inplace_all_reduce for local case becaues of custom all reduce.
NUM_GPUS_PER_NODE = 8
if (
not local_tokens.dtype.is_floating_point
and get_tensor_model_parallel_world_size() <= NUM_GPUS_PER_NODE
):
torch.ops.sglang.inplace_all_reduce(
global_tokens, group_name=get_tp_group().unique_name
)
else:
global_tokens[:] = tensor_model_parallel_all_reduce(global_tokens)
def dp_gather_partial(
global_tokens: torch.Tensor,
local_tokens: torch.Tensor,
forward_batch: ForwardBatch,
):
_dp_gather(global_tokens, local_tokens, forward_batch, is_partial=True)
def dp_gather_replicate(
global_tokens: torch.Tensor,
local_tokens: torch.Tensor,
forward_batch: ForwardBatch,
):
_dp_gather(global_tokens, local_tokens, forward_batch, is_partial=False)
def dp_scatter(
local_tokens: torch.Tensor, # output
global_tokens: torch.Tensor, # input
forward_batch: ForwardBatch,
):
# local_num_tokens is not necessarily the same as local_tokens.shape[0],
# since local_tokens may be padded for cuda graph
local_start_pos, local_num_tokens = get_dp_local_info(forward_batch)
local_tokens.fill_(0)
assert local_tokens.is_contiguous()
assert global_tokens.is_contiguous()
if local_tokens.shape[0] > 0:
assert (
local_tokens.untyped_storage().data_ptr()
!= global_tokens.untyped_storage().data_ptr()
), "aliasing between local_tokens and global_tokens not allowed"
memcpy_triton(
local_tokens, global_tokens, 0, local_start_pos, local_num_tokens, True
)
def tp_reduce_scatter(
output: torch.Tensor,
input_list: List[torch.Tensor],
):
return get_attention_tp_group().reduce_scatter(output, input_list)
def tp_all_gather(output_list: List[torch.Tensor], input_: torch.Tensor):
return get_attention_tp_group().all_gather(input_, tensor_list=output_list)