Files
aituner/runs/frontier-qwen30-vllm020-profile-v1/profile_vllm020_allreduce.py

346 lines
14 KiB
Python

#!/usr/bin/env python3
"""Profile the vLLM 0.20 TP all-reduce path under a frozen runtime contract."""
from __future__ import annotations
import argparse
import json
import os
import statistics
import subprocess
from pathlib import Path
from typing import Any
import torch
import torch.distributed as dist
import vllm
VLLM_VERSION = "0.20.0"
VLLM_COMMIT = "88d34c6409e9fb3c7b8ca0c04756f061d2099eb1"
def parse_args() -> argparse.Namespace:
parser = argparse.ArgumentParser()
parser.add_argument("--vllm-source", type=Path, required=True)
parser.add_argument("--model", type=Path, required=True)
parser.add_argument("--output", type=Path, required=True)
parser.add_argument("--num-tokens", type=int, nargs="+", default=[8])
parser.add_argument("--hidden-dim", type=int, default=2048)
parser.add_argument(
"--collective-contract",
choices=("flashinfer-trtllm", "qwen235-serving-projected"),
default="flashinfer-trtllm",
)
parser.add_argument("--warmup-iters", type=int, default=3)
parser.add_argument("--repeats", type=int, default=10)
parser.add_argument("--trials", type=int, default=1)
return parser.parse_args()
def git_head(repo: Path) -> str:
return subprocess.check_output(
["git", "-C", str(repo), "rev-parse", "HEAD"], text=True
).strip()
def stats_ms(samples: list[float]) -> dict[str, float]:
return {
"min": min(samples),
"max": max(samples),
"mean": statistics.fmean(samples),
"median": statistics.median(samples),
"std": statistics.pstdev(samples),
}
def main() -> None:
args = parse_args()
if vllm.__version__ != VLLM_VERSION:
raise SystemExit(f"expected vLLM {VLLM_VERSION}, got {vllm.__version__}")
source_head = git_head(args.vllm_source)
if source_head != VLLM_COMMIT:
raise SystemExit(f"expected vLLM source {VLLM_COMMIT}, got {source_head}")
if args.repeats <= 0 or args.trials <= 0 or args.warmup_iters < 0:
raise SystemExit("warmup/repeats/trials must be non-negative/positive")
if os.getenv("VLLM_ALLREDUCE_USE_FLASHINFER") != "1":
raise SystemExit("VLLM_ALLREDUCE_USE_FLASHINFER must equal 1")
if os.getenv("VLLM_FLASHINFER_ALLREDUCE_BACKEND") != "trtllm":
raise SystemExit("VLLM_FLASHINFER_ALLREDUCE_BACKEND must equal trtllm")
expected_symm_mem = (
"1" if args.collective_contract == "qwen235-serving-projected" else "0"
)
if os.getenv("VLLM_ALLREDUCE_USE_SYMM_MEM") != expected_symm_mem:
raise SystemExit(
f"VLLM_ALLREDUCE_USE_SYMM_MEM must equal {expected_symm_mem}"
)
if "RANK" not in os.environ or "WORLD_SIZE" not in os.environ:
raise SystemExit("launch with torchrun")
from vllm.distributed import (
destroy_distributed_environment,
destroy_model_parallel,
init_distributed_environment,
initialize_model_parallel,
set_custom_all_reduce,
tensor_model_parallel_all_reduce,
)
from vllm.distributed.parallel_state import get_tp_group
from vllm.config import (
ModelConfig,
ParallelConfig,
VllmConfig,
set_current_vllm_config,
)
rank = int(os.environ["RANK"])
local_rank = int(os.environ["LOCAL_RANK"])
world_size = int(os.environ["WORLD_SIZE"])
if world_size not in (2, 4, 8):
raise SystemExit(f"expected TP world size 2, 4, or 8, got {world_size}")
device = torch.device(f"cuda:{local_rank}")
torch.accelerator.set_device_index(device)
torch.set_default_device(device)
disable_custom_all_reduce = (
args.collective_contract == "qwen235-serving-projected"
)
set_custom_all_reduce(not disable_custom_all_reduce)
init_distributed_environment()
model_config = ModelConfig(
model=str(args.model),
dtype="bfloat16",
max_model_len=8192,
skip_tokenizer_init=True,
generation_config="vllm",
)
vllm_config = VllmConfig(
model_config=model_config,
parallel_config=ParallelConfig(
tensor_parallel_size=world_size,
disable_custom_all_reduce=disable_custom_all_reduce,
)
)
with set_current_vllm_config(vllm_config):
initialize_model_parallel(tensor_model_parallel_size=world_size)
from vllm.distributed.device_communicators.all_reduce_utils import (
should_nccl_symm_mem_allreduce,
)
def resolve_profile_operation(input_tensor: torch.Tensor):
communicator = get_tp_group().device_communicator
if args.collective_contract == "qwen235-serving-projected":
from vllm.compilation.passes.fusion.allreduce_rms_fusion import (
FI_ALLREDUCE_FUSION_MAX_SIZE_MB,
)
major, minor = torch.cuda.get_device_capability(device)
capability = major * 10 + minor
try:
fusion_limit_bytes = int(
FI_ALLREDUCE_FUSION_MAX_SIZE_MB[capability][world_size]
* 1024
* 1024
)
except KeyError as error:
raise SystemExit(
f"no FlashInfer fusion limit for SM{capability}, TP{world_size}"
) from error
if input_tensor.nbytes <= fusion_limit_bytes:
from vllm.distributed.device_communicators.flashinfer_all_reduce import (
get_fi_ar_workspace,
)
fi_comm = communicator.fi_ar_comm
if fi_comm is None or fi_comm.disabled:
raise SystemExit("FlashInfer all-reduce communicator is unavailable")
max_token_num = fusion_limit_bytes // (
args.hidden_dim * input_tensor.element_size()
)
workspace = get_fi_ar_workspace(
world_size=world_size,
rank=rank,
max_token_num=max_token_num,
hidden_dim=args.hidden_dim,
dtype=input_tensor.dtype,
group=get_tp_group().device_group,
)
if workspace is None:
raise SystemExit(
"FlashInfer rejected the serving-matched integer workspace"
)
if not fi_comm.should_use_fi_ar(input_tensor):
raise SystemExit("FlashInfer rejected a fusion-eligible payload")
return (
"flashinfer_trtllm_fused_projection",
fi_comm.all_reduce,
fusion_limit_bytes,
)
if (
communicator.pynccl_comm is not None
and should_nccl_symm_mem_allreduce(world_size, input_tensor)
):
return (
"pynccl_symmetric_with_copy",
torch.ops.vllm.all_reduce_symmetric_with_copy,
fusion_limit_bytes,
)
if (
communicator.symm_mem_comm is not None
and communicator.symm_mem_comm.should_use_symm_mem(input_tensor)
):
return (
"torch_symmetric_memory",
communicator.symm_mem_comm.all_reduce,
fusion_limit_bytes,
)
if communicator.pynccl_comm is not None:
return "pynccl", communicator.pynccl_comm.all_reduce, fusion_limit_bytes
return "torch_distributed", tensor_model_parallel_all_reduce, fusion_limit_bytes
fi_comm = communicator.fi_ar_comm
selected_backend = (
"flashinfer_trtllm"
if fi_comm is not None
and not fi_comm.disabled
and fi_comm.should_use_fi_ar(input_tensor)
else "non_flashinfer_fallback"
)
return selected_backend, tensor_model_parallel_all_reduce, None
rows: list[dict[str, Any]] = []
expected_sum = world_size * (world_size + 1) / 2
try:
for num_tokens in args.num_tokens:
input_tensor = torch.full(
(num_tokens, args.hidden_dim),
float(rank + 1),
dtype=torch.bfloat16,
device=device,
)
selected_backend, profile_operation, fusion_limit_bytes = (
resolve_profile_operation(input_tensor)
)
for _ in range(args.warmup_iters):
output = profile_operation(input_tensor)
torch.accelerator.synchronize()
torch.testing.assert_close(
output,
torch.full_like(output, expected_sum),
atol=0.0,
rtol=0.0,
)
if args.collective_contract == "flashinfer-trtllm":
if selected_backend != "flashinfer_trtllm":
raise SystemExit(
f"expected FlashInfer TRTLLM, got {selected_backend} at "
f"TP={world_size}, tokens={num_tokens}"
)
elif selected_backend not in {
"flashinfer_trtllm_fused_projection",
"pynccl_symmetric_with_copy",
"torch_symmetric_memory",
"pynccl",
}:
raise SystemExit(
f"unexpected Qwen235 serving backend: {selected_backend}"
)
all_trial_rank_samples: list[list[list[float]]] = []
critical_path_samples: list[float] = []
for _ in range(args.trials):
samples: list[float] = []
for _ in range(args.repeats):
dist.barrier()
start = torch.cuda.Event(enable_timing=True)
end = torch.cuda.Event(enable_timing=True)
start.record()
output = profile_operation(input_tensor)
end.record()
torch.accelerator.synchronize()
samples.append(float(start.elapsed_time(end)))
gathered: list[list[float] | None] = [None] * world_size
dist.all_gather_object(gathered, samples)
if rank == 0:
rank_samples = [item for item in gathered if item is not None]
all_trial_rank_samples.append(rank_samples)
critical_path_samples.extend(
max(per_rank[index] for per_rank in rank_samples)
for index in range(args.repeats)
)
if rank == 0:
flattened_by_rank = [
[
sample
for trial in all_trial_rank_samples
for sample in trial[rank_index]
]
for rank_index in range(world_size)
]
per_rank = [stats_ms(samples) for samples in flattened_by_rank]
row = {
"tensor_parallel_size": world_size,
"num_tokens": num_tokens,
"hidden_dim": args.hidden_dim,
"payload_bytes": num_tokens
* args.hidden_dim
* torch.tensor([], dtype=torch.bfloat16).element_size(),
"dtype": "bfloat16",
"communicator": "vllm.tensor_model_parallel_all_reduce",
"collective_contract": args.collective_contract,
"selected_backend": selected_backend,
"real_fusion_limit_bytes": fusion_limit_bytes,
"trials": args.trials,
"repeats_per_trial": args.repeats,
"per_trial_rank_samples_ms": all_trial_rank_samples,
"per_rank_time_ms": per_rank,
"critical_path_time_ms": stats_ms(critical_path_samples),
"critical_path_median_ms": statistics.median(
critical_path_samples
),
}
rows.append(row)
print(json.dumps(row, sort_keys=True), flush=True)
finally:
destroy_model_parallel()
destroy_distributed_environment()
if rank == 0:
payload = {
"schema_version": (
"qwen30_vllm020_allreduce_raw.v1"
if args.collective_contract == "flashinfer-trtllm"
else "vllm020_allreduce_raw.v2"
),
"environment": {
"vllm_version": vllm.__version__,
"vllm_source_commit": source_head,
"torch_version": torch.__version__,
"torch_cuda": torch.version.cuda,
"gpu": torch.cuda.get_device_name(device),
"model": str(args.model),
"backend_env": {
"VLLM_ALLREDUCE_USE_FLASHINFER": os.getenv(
"VLLM_ALLREDUCE_USE_FLASHINFER", "0"
),
"VLLM_FLASHINFER_ALLREDUCE_BACKEND": os.getenv(
"VLLM_FLASHINFER_ALLREDUCE_BACKEND"
),
"VLLM_ALLREDUCE_USE_SYMM_MEM": os.getenv(
"VLLM_ALLREDUCE_USE_SYMM_MEM", "1"
),
},
"collective_contract": args.collective_contract,
"disable_custom_all_reduce": disable_custom_all_reduce,
},
"rows": rows,
}
args.output.parent.mkdir(parents=True, exist_ok=True)
args.output.write_text(json.dumps(payload, indent=2, sort_keys=True) + "\n")
if __name__ == "__main__":
main()