sglang.0.4.8.post1/sglang/test/srt/test_deepep_low_latency.py

326 lines
12 KiB
Python

# Copy from deepseek-ai/DeepEP/tests/test_low_latency.py
import random
from functools import partial
import deep_ep
import torch
import torch.distributed as dist
from sglang.test.test_deepep_utils import (
bench,
bench_kineto,
calc_diff,
hash_tensor,
init_dist,
per_token_cast_back,
)
def test_main(
num_tokens: int,
hidden: int,
num_experts: int,
num_topk: int,
rank: int,
num_ranks: int,
group: dist.ProcessGroup,
buffer: deep_ep.Buffer,
seed: int = 0,
):
torch.manual_seed(seed + rank)
random.seed(seed + rank)
assert num_experts % num_ranks == 0
num_local_experts = num_experts // num_ranks
# NOTES: the integers greater than 256 exceeds the BF16 precision limit
rank_offset = 128
assert (
num_ranks - rank_offset < 257
), "Too many ranks (exceeding test precision limit)"
x = torch.ones((num_tokens, hidden), dtype=torch.bfloat16, device="cuda") * (
rank - rank_offset
)
x[:, -128:] = torch.arange(num_tokens, device="cuda").to(torch.bfloat16).view(-1, 1)
scores = (
torch.randn((num_tokens, num_experts), dtype=torch.float32, device="cuda").abs()
+ 1
)
topk_idx = torch.topk(scores, num_topk, dim=-1, largest=True, sorted=True)[1]
topk_weights = torch.randn(
(num_tokens, num_topk), dtype=torch.float32, device="cuda"
).abs()
# Randomly mask some positions
for i in range(10):
topk_idx[random.randint(0, num_tokens - 1), random.randint(0, num_topk - 1)] = (
-1
)
# Check dispatch correctness
do_check = True
hash_value, num_times = 0, 0
for return_recv_hook in (False, True):
for dispatch_use_fp8 in (False, True):
num_times += 1
for i in range((num_times % 2) + 1):
packed_recv_x, packed_recv_count, handle, event, hook = (
buffer.low_latency_dispatch(
x,
topk_idx,
num_tokens,
num_experts,
use_fp8=dispatch_use_fp8,
async_finish=not return_recv_hook,
return_recv_hook=return_recv_hook,
)
)
hook() if return_recv_hook else event.current_stream_wait()
packed_recv_x = (
(packed_recv_x[0], packed_recv_x[1].contiguous())
if dispatch_use_fp8
else packed_recv_x
)
simulated_gemm_x = (
per_token_cast_back(
packed_recv_x[0].view(-1, hidden),
packed_recv_x[1].view(-1, hidden // 128),
).view(packed_recv_x[0].shape)
if dispatch_use_fp8
else packed_recv_x.clone()
)
all_topk_idx = torch.empty(
(num_ranks, num_tokens, num_topk), dtype=topk_idx.dtype, device="cuda"
)
dist.all_gather_into_tensor(all_topk_idx, topk_idx, group=group)
for i in range(num_local_experts if do_check else 0):
expert_id = rank * num_local_experts + i
recv_x = (
per_token_cast_back(packed_recv_x[0][i], packed_recv_x[1][i])
if dispatch_use_fp8
else packed_recv_x[i]
)
recv_count, recv_src_info, recv_layout_range = (
packed_recv_count[i],
handle[0][i],
handle[1][i],
)
# Check expert indices
int_mask = (2**32) - 1
num_valid_tokens = recv_count.item()
assert (
num_valid_tokens == (recv_layout_range & int_mask).sum().item()
), f"{num_valid_tokens} != {recv_layout_range & int_mask}.sum().item()"
assert (
num_valid_tokens == (all_topk_idx == expert_id).sum().item()
), f"{num_valid_tokens} != {(all_topk_idx == expert_id).sum().item()}"
# Check received data
recv_x = recv_x[:num_valid_tokens]
recv_x_amin = recv_x[:, :-128].amin(dim=-1)
recv_src_info = recv_src_info[:num_valid_tokens]
assert torch.equal(recv_x_amin, recv_x[:, :-128].amax(dim=-1))
assert (
recv_x[:, -128:] - recv_src_info.view(-1, 1) % num_tokens
).sum().item() == 0
for j in range(num_ranks):
begin_idx, count = (recv_layout_range[j] >> 32).item(), (
recv_layout_range[j] & int_mask
).item()
assert (recv_x_amin == j - rank_offset).sum().item() == (
all_topk_idx[j] == expert_id
).sum().item()
assert (
recv_x[begin_idx : begin_idx + count][:-128] - j
).sum().item() == 0
if dispatch_use_fp8:
hash_value ^= hash_tensor(packed_recv_x[0][i, :num_valid_tokens])
hash_value ^= hash_tensor(packed_recv_x[1][i, :num_valid_tokens])
else:
hash_value ^= hash_tensor(packed_recv_x[i, :num_valid_tokens])
# Check combine correctness
for zero_copy in (False, True):
if zero_copy:
buffer.get_next_low_latency_combine_buffer(handle)[
:, :, :
] = simulated_gemm_x
out = torch.empty(
(num_tokens, hidden), dtype=torch.bfloat16, device="cuda"
)
combined_x, event, hook = buffer.low_latency_combine(
simulated_gemm_x,
topk_idx,
topk_weights,
handle,
async_finish=not return_recv_hook,
zero_copy=zero_copy,
return_recv_hook=return_recv_hook,
out=out,
)
hook() if return_recv_hook else event.current_stream_wait()
if do_check:
diff = calc_diff(
x
* topk_weights.masked_fill(topk_idx == -1, 0)
.sum(dim=1)
.view(-1, 1),
combined_x,
)
assert torch.isnan(combined_x).sum().item() == 0
assert diff < 1e-5, f"Error: {diff=}, {zero_copy=}"
hash_value ^= hash_tensor(combined_x)
def create_test_cast_with_outliers(num_outliers):
tmp = torch.randn((num_tokens, hidden), dtype=torch.bfloat16, device="cuda")
tmp /= tmp.abs().amax(dim=1).view(-1, 1)
assert tmp.abs().amax().item() <= 1
# Create some amax outliers
for i in range(num_outliers):
tmp[random.randint(0, num_tokens - 1)] *= 1e3
return tmp
# noinspection PyShadowingNames
def large_gemm_with_hook(hook):
mat_0 = torch.randn((8192, 8192), dtype=torch.float)
mat_1 = torch.randn((8192, 8192), dtype=torch.float)
mat_0 @ mat_1
hook()
# noinspection PyShadowingNames
def test_func(zero_copy: bool, return_recv_hook: bool):
recv_x, recv_count, handle, event, hook = buffer.low_latency_dispatch(
x,
topk_idx,
num_tokens,
num_experts,
async_finish=False,
return_recv_hook=return_recv_hook,
)
large_gemm_with_hook(hook) if return_recv_hook else None
if zero_copy:
buffer.get_next_low_latency_combine_buffer(handle)[
:, :, :
] = simulated_gemm_x
combined_x, event, hook = buffer.low_latency_combine(
simulated_gemm_x,
topk_idx,
topk_weights,
handle,
zero_copy=zero_copy,
return_recv_hook=return_recv_hook,
)
large_gemm_with_hook(hook) if return_recv_hook else None
# Calculate bandwidth
num_fp8_bytes, num_bf16_bytes = (hidden + hidden / 128 * 4 + 16), hidden * 2
num_dispatch_comm_bytes, num_combine_comm_bytes = 0, 0
for i in range(num_tokens):
num_selections = (topk_idx[i] != -1).sum().item()
num_dispatch_comm_bytes += num_fp8_bytes * num_selections
num_combine_comm_bytes += num_bf16_bytes * num_selections
# Dispatch + combine testing
avg_t, min_t, max_t = bench(
partial(test_func, zero_copy=False, return_recv_hook=False)
)
print(
f"[rank {rank}] Dispatch + combine bandwidth: {(num_dispatch_comm_bytes + num_combine_comm_bytes) / 1e9 / avg_t:.2f} GB/s, "
f"avg_t={avg_t * 1e6:.2f} us, min_t={min_t * 1e6:.2f} us, max_t={max_t * 1e6:.2f} us",
flush=True,
)
# Separate profiling
for return_recv_hook in (False, True):
group.barrier()
dispatch_t, combine_t = bench_kineto(
partial(test_func, zero_copy=True, return_recv_hook=return_recv_hook),
kernel_names=("dispatch", "combine"),
barrier_comm_profiling=True,
suppress_kineto_output=True,
)
if not return_recv_hook:
print(
f"[rank {rank}] Dispatch bandwidth: {num_dispatch_comm_bytes / 1e9 / dispatch_t:.2f} GB/s, avg_t={dispatch_t * 1e6:.2f} us | "
f"Combine bandwidth: {num_combine_comm_bytes / 1e9 / combine_t:.2f} GB/s, avg_t={combine_t * 1e6:.2f} us",
flush=True,
)
else:
print(
f"[rank {rank}] Dispatch send/recv time: {dispatch_t * 2 * 1e6:.2f} us | "
f"Combine send/recv time: {combine_t * 2 * 1e6:.2f} us",
flush=True,
)
return hash_value
# noinspection PyUnboundLocalVariable
def test_loop(local_rank: int, num_local_ranks: int):
rank, num_ranks, group = init_dist(local_rank, num_local_ranks)
num_tokens, hidden, num_topk, num_experts = 128, 7168, 8, 288
num_rdma_bytes = deep_ep.Buffer.get_low_latency_rdma_size_hint(
num_tokens, hidden, num_ranks, num_experts
)
if local_rank == 0:
print(f"Allocating buffer size: {num_rdma_bytes / 1e6} MB ...", flush=True)
buffer = deep_ep.Buffer(
group,
num_rdma_bytes=num_rdma_bytes,
low_latency_mode=True,
num_qps_per_rank=num_experts // num_ranks,
)
test_main(
num_tokens,
hidden,
num_experts,
num_topk,
rank,
num_ranks,
group,
buffer,
seed=1,
)
do_pressure_test = False
for seed in range(int(1e9) if do_pressure_test else 0):
if local_rank == 0:
print(f"Testing with seed {seed} ...", flush=True)
ref_hash = test_main(
num_tokens,
hidden,
num_experts,
num_topk,
rank,
num_ranks,
group,
buffer,
seed=seed,
)
for i in range(20):
assert (
test_main(
num_tokens,
hidden,
num_experts,
num_topk,
rank,
num_ranks,
group,
buffer,
seed=seed,
)
== ref_hash
), f"Error: seed={seed}"
if __name__ == "__main__":
# TODO: you may modify NUMA binding for less CPU overhead
num_processes = 8
torch.multiprocessing.spawn(test_loop, args=(num_processes,), nprocs=num_processes)