[WIP] Before add Quest policy.

This commit is contained in:
Zijie Tian
2026-01-07 02:32:30 +08:00
parent f240903013
commit c99a6f3d3f
11 changed files with 166 additions and 191 deletions

View File

@@ -3,11 +3,6 @@ import time
from random import randint, seed
from nanovllm import LLM, SamplingParams
# Import sparse policy classes
from nanovllm.kvcache.sparse.quest import QuestPolicy, QuestConfig, BlockMetadataManager
from nanovllm.kvcache.sparse.hybrid import HybridPolicy
from nanovllm.kvcache.sparse.full_policy import FullAttentionPolicy
def bench_decode(llm, num_seqs, input_len, output_len):
"""Benchmark decode performance (original test)"""
@@ -38,58 +33,6 @@ def bench_prefill(llm, num_seqs, input_len):
print(f"[Prefill] Input: {total_input_tokens}tok ({num_seqs}x{input_len}), Time: {t:.2f}s, Throughput: {throughput:.2f}tok/s")
def setup_quest_policy(llm, topk_blocks=8, threshold_blocks=4):
"""
Setup Quest sparse policy for decode phase.
Uses HybridPolicy: Full attention for prefill, Quest Top-K for decode.
"""
import torch
kvcache_manager = llm.model_runner.kvcache_manager
offload_engine = kvcache_manager.offload_engine
# Get model parameters from offload engine
num_layers = offload_engine.num_layers
num_kv_heads = offload_engine.num_kv_heads
head_dim = offload_engine.head_dim
num_cpu_blocks = kvcache_manager.num_cpu_blocks
dtype = offload_engine.k_cache_cpu.dtype
print(f"Setting up Quest policy:")
print(f" num_layers={num_layers}, num_kv_heads={num_kv_heads}, head_dim={head_dim}")
print(f" num_cpu_blocks={num_cpu_blocks}, dtype={dtype}")
print(f" topk_blocks={topk_blocks}, threshold_blocks={threshold_blocks}")
# Create BlockMetadataManager for storing min/max keys
metadata = BlockMetadataManager(
num_blocks=num_cpu_blocks,
num_layers=num_layers,
num_kv_heads=num_kv_heads,
head_dim=head_dim,
dtype=dtype,
)
# Create Quest policy for decode
quest_config = QuestConfig(
topk_blocks=topk_blocks,
threshold_blocks=threshold_blocks,
)
quest_policy = QuestPolicy(quest_config, metadata)
# Create Hybrid policy: Full for prefill, Quest for decode
hybrid_policy = HybridPolicy(
prefill_policy=FullAttentionPolicy(),
decode_policy=quest_policy,
)
# Set the policy
kvcache_manager.set_sparse_policy(hybrid_policy)
print(f" Policy set: HybridPolicy(prefill=Full, decode=Quest)")
return hybrid_policy
def main():
import argparse
parser = argparse.ArgumentParser()
@@ -101,7 +44,18 @@ def main():
path = os.path.expanduser("~/models/Qwen3-4B-Instruct-2507/")
# Note: Qwen3-4B-Instruct-2507 max_position_embeddings = 262144
max_len = 131072 # 128K tokens
max_len = 32 * 1024 # 128K tokens
# Setup policy configuration
if not args.no_sparse:
prefill_policy = "full" # Full attention for prefill
decode_policy = "quest" # Quest Top-K for decode
print(f"\n[Quest Sparse Attention] prefill={prefill_policy}, decode={decode_policy}, topk={args.topk}")
else:
prefill_policy = "full" # Full attention for both phases
decode_policy = "full"
print("\n[Full Attention] No sparse policy (baseline)")
llm = LLM(
path,
enforce_eager=False,
@@ -109,15 +63,12 @@ def main():
max_num_batched_tokens=max_len,
enable_cpu_offload=True,
num_gpu_blocks=6, # Small GPU buffer for offload testing
prefill_policy=prefill_policy,
decode_policy=decode_policy,
sparse_topk_blocks=args.topk,
sparse_threshold_blocks=4,
)
if not args.no_sparse:
# Setup Quest policy for decode (Top-K blocks, apply when > 4 blocks)
setup_quest_policy(llm, topk_blocks=args.topk, threshold_blocks=4)
print(f"\n[Quest Sparse Attention] topk={args.topk}")
else:
print("\n[Full Attention] No sparse policy (baseline)")
# Warmup
llm.generate(["Benchmark: "], SamplingParams())