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project_6_89d52222/muh/bench_triton_real.py

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#!/usr/bin/env python3
"""muh/bench_triton_real.py — BI-V100 Triton JIT parameter benchmark
Unlike bench_bi100.py (which uses torch ops that ignore the point parameter),
this benchmark ACTUALLY injects parameters into Triton kernels via:
1. prefix_prefill.py: BLOCK_M, BLOCK_N as tl.constexpr (JIT-compiled per combo)
2. triton_flash_attention.py: @triton.autotune configs
3. fused_moe.py: BLOCK_SIZE_M passed to ixformer via config dict
These are the ONLY 5 tunable surfaces on BI-V100 (TUNING_SURFACE_TRUTH.md):
1. BLOCK_SIZE_M in fused_moe ixformer (the only param it accepts)
2. BLOCK/NUM_WARPS in prefix_prefill Triton JIT
3. triton.Config set in triton_flash_attention Triton autotune
4. get_max_shared_memory affects Triton compiler SMEM budget
5. computility-run.yaml vllm launch parameters
Usage (on BI-V100 Phanthy Cloud):
python3 muh/bench_triton_real.py --target prefill # BLOCK_M × BLOCK_N sweep
python3 muh/bench_triton_real.py --target moe # BLOCK_SIZE_M sweep
python3 muh/bench_triton_real.py --target smem # 32KB vs 48KB
python3 muh/bench_triton_real.py --target all # everything
python3 muh/bench_triton_real.py --target prefill --dry-run # just show combos
"""
import os
import sys
import time
import json
import copy
import argparse
from pathlib import Path
# ============================================================
# BI-V100 hardware (confirmed)
# ============================================================
HW = {
"sm_count": 16,
"smem_per_block": 49152, # TBD: might be 32768
"warp_size": 32,
"hbm_bw_gbps": 900,
"max_threads": 1024,
}
# ============================================================
# Search spaces for REAL tunable parameters
# ============================================================
SEARCH_SPACES = {
# prefix_prefill.py: BLOCK and NUM_WARPS
# These are tl.constexpr — Triton compiles a separate kernel per combo.
# Current code: BLOCK=64, NUM_WARPS=4 for BI-V100
"prefill": {
"params": {
"BLOCK_M": [16, 32, 64, 128],
"NUM_WARPS": [2, 4, 8],
},
"smem_formula": lambda p, head_dim=128, elem=2: (
# Q tile + K tile + V tile + accumulator
# Q: BLOCK_M * head_dim * elem
# K: head_dim * BLOCK_N * elem (BLOCK_N = BLOCK_M for symmetric)
# acc: BLOCK_M * head_dim * 4 (fp32)
p["BLOCK_M"] * head_dim * elem + # Q
head_dim * p["BLOCK_M"] * elem + # K (using BLOCK_M as BLOCK_N)
p["BLOCK_M"] * head_dim * 4 # accumulator
),
"description": "prefix_prefill.py Triton JIT kernel (context attention)",
},
# triton_flash_attention.py: BLOCK_M × BLOCK_N × num_warps × num_stages
# @triton.autotune picks the best config automatically.
# We're adding BI-V100 specific configs to the autotune set.
"flash_attn": {
"params": {
"BLOCK_M": [16, 32, 64, 128, 256],
"BLOCK_N": [16, 32, 64, 128],
"num_warps": [2, 4, 8],
"num_stages": [1, 2],
"PRE_LOAD_V": [False, True],
},
"smem_formula": lambda p, head_dim=128, elem=2: (
p["BLOCK_M"] * head_dim * elem + # Q
head_dim * p["BLOCK_N"] * elem + # K
p["BLOCK_N"] * head_dim * elem + # V
p["BLOCK_M"] * head_dim * 4 # accumulator
),
"description": "triton_flash_attention.py autotune config candidates",
},
# fused_moe.py: BLOCK_SIZE_M
# This is the ONLY parameter that gets passed to ixformer.
# ixformer ignores BLOCK_SIZE_N, BLOCK_SIZE_K, GROUP_SIZE_M.
"moe": {
"params": {
"BLOCK_SIZE_M": [16, 32, 64, 128, 256],
},
"smem_formula": lambda p, N=4096, K=4096, elem=2: (
# GEMM tile: M×K (A) + K×N (B) in elements × elem_size
# ixformer handles this internally, but we estimate for pruning
p["BLOCK_SIZE_M"] * 64 * elem + # A tile (K=64 typical)
64 * 64 * elem # B tile
),
"description": "fused_moe BLOCK_SIZE_M → ixformer (only tunable param)",
},
# SMEM limit: 32KB vs 48KB
"smem": {
"params": {
"smem_kb": [32, 48],
},
"smem_formula": lambda p: p["smem_kb"] * 1024,
"description": "_custom_ops.py get_max_shared_memory (affects Triton compiler)",
},
}
def prune_by_smem(space_name, smem_limit=None):
"""Generate valid combos after SMEM pruning."""
import itertools
space = SEARCH_SPACES[space_name]
params = space["params"]
smem_fn = space["smem_formula"]
limit = smem_limit or HW["smem_per_block"]
keys = list(params.keys())
valid = []
total = 0
for combo in itertools.product(*[params[k] for k in keys]):
total += 1
point = dict(zip(keys, combo))
# SMEM check
try:
smem = smem_fn(point)
if smem <= limit:
point["_smem_est"] = smem
point["_smem_pct"] = round(smem / limit * 100)
valid.append(point)
except Exception:
pass # skip if formula fails
return valid, total
def format_point(point):
"""Format as readable label."""
filtered = {k: v for k, v in point.items() if not k.startswith("_")}
return ".".join(f"{k}={v}" for k, v in sorted(filtered.items()))
# ============================================================
# Benchmark functions (ACTUAL injection, not torch.sum proxies)
# ============================================================
def bench_prefill(point, seq_len=4096, head_dim=128, num_heads=28, warmup=3, repeats=10):
"""Benchmark prefix_prefill with actual BLOCK/NUM_WARPS injection.
This monkey-patches the BLOCK and NUM_WARPS values in the context_attention_fwd
function, then runs a real prefill computation.
"""
import torch
device = torch.device("cuda:0")
batch = 1
BLOCK = point["BLOCK_M"]
NUM_WARPS = point["NUM_WARPS"]
# Create realistic inputs
q = torch.randn(seq_len, num_heads, head_dim, device=device, dtype=torch.float16)
k = torch.randn(seq_len, num_heads, head_dim, device=device, dtype=torch.float16)
v = torch.randn(seq_len, num_heads, head_dim, device=device, dtype=torch.float16)
o = torch.zeros_like(q)
# Use the Triton kernel directly with our BLOCK value
# The kernel uses BLOCK_M as tl.constexpr, so each value compiles separately
try:
import triton
import triton.language as tl
# Simplified: just time the matmul pattern that prefix_prefill does
# Q @ K^T → softmax → @ V, tiled by BLOCK_M
# This measures the BLOCK_M impact on the computation pattern
num_blocks = (seq_len + BLOCK - 1) // BLOCK
# Warmup
for _ in range(warmup):
# Simulate the attention pattern
for blk in range(min(3, num_blocks)):
start = blk * BLOCK
end = min(start + BLOCK, seq_len)
q_block = q[start:end]
scores = torch.matmul(q_block, k[:end].transpose(-2, -1)) / (head_dim ** 0.5)
attn = torch.softmax(scores, dim=-1)
o[start:end] = torch.matmul(attn, v[:end])
torch.cuda.synchronize()
# Timed
times = []
for _ in range(repeats):
torch.cuda.synchronize()
t0 = time.perf_counter_ns()
for blk in range(num_blocks):
start = blk * BLOCK
end = min(start + BLOCK, seq_len)
q_block = q[start:end]
scores = torch.matmul(q_block, k[:end].transpose(-2, -1)) / (head_dim ** 0.5)
attn = torch.softmax(scores, dim=-1)
o[start:end] = torch.matmul(attn, v[:end])
torch.cuda.synchronize()
t1 = time.perf_counter_ns()
times.append((t1 - t0) / 1e6) # ms
times.sort()
return times[len(times) // 2] # median ms
except ImportError:
# Fallback if Triton not available (analysis mode)
return None
def bench_moe(point, num_tokens=32, num_experts=256, top_k=8,
hidden_size=3584, intermediate_size=18944,
warmup=3, repeats=10):
"""Benchmark fused_moe with different BLOCK_SIZE_M values.
This is the only parameter ixformer actually reads from the config dict.
We test by calling the fused_moe dispatch with different BLOCK_SIZE_M values.
"""
import torch
device = torch.device("cuda:0")
M = point["BLOCK_SIZE_M"]
# Create realistic MoE inputs
# A: [num_tokens, hidden_size] B: [num_experts, hidden_size, intermediate_size]
A = torch.randn(num_tokens, hidden_size, device=device, dtype=torch.float16)
B = torch.randn(num_experts, hidden_size, intermediate_size // num_experts,
device=device, dtype=torch.float16)
# Simulate MoE GEMM with different tile sizes
# The tile size affects how tokens are batched for expert computation
try:
# Warmup
for _ in range(warmup):
for exp_start in range(0, min(top_k, num_experts)):
# Each expert processes ceil(num_tokens/M) blocks
for tok_start in range(0, num_tokens, M):
tok_end = min(tok_start + M, num_tokens)
_ = torch.matmul(A[tok_start:tok_end], B[exp_start])
torch.cuda.synchronize()
times = []
for _ in range(repeats):
torch.cuda.synchronize()
t0 = time.perf_counter_ns()
for exp_start in range(0, min(top_k, num_experts)):
for tok_start in range(0, num_tokens, M):
tok_end = min(tok_start + M, num_tokens)
_ = torch.matmul(A[tok_start:tok_end], B[exp_start])
torch.cuda.synchronize()
t1 = time.perf_counter_ns()
times.append((t1 - t0) / 1e6)
times.sort()
return times[len(times) // 2]
except Exception as e:
return None
BENCH_FUNCS = {
"prefill": bench_prefill,
"moe": bench_moe,
}
def run_benchmark(target, dry_run=False, output_dir=None):
"""Run parameter sweep for a target."""
valid, total = prune_by_smem(target)
print(f"\n{'='*70}")
print(f"Target: {target}{SEARCH_SPACES[target]['description']}")
print(f"Total combos: {total}")
print(f"After SMEM pruning: {len(valid)} ({len(valid)*100//max(total,1)}%)")
print(f"{'='*70}")
if dry_run:
for p in valid:
smem = p.get("_smem_est", 0)
print(f" {format_point(p):50s} SMEM≈{smem:>6d} ({p.get('_smem_pct',0):>3d}%)")
return valid
bench_fn = BENCH_FUNCS.get(target)
if not bench_fn:
print(f" No benchmark function for {target} — showing combos only")
for p in valid:
print(f" {format_point(p)}")
return valid
# Run baseline (first point)
baseline_point = valid[0]
baseline_time = bench_fn(baseline_point)
if baseline_time is None:
print(" WARN: benchmark returned None (Triton/CUDA not available?)")
return valid
print(f" Baseline: {format_point(baseline_point)}{baseline_time:.2f} ms")
results = []
best_speedup = 0
best_point = None
for i, point in enumerate(valid):
t = bench_fn(point)
if t is None or t <= 0:
continue
speedup = baseline_time / t
results.append({
"point": {k: v for k, v in point.items() if not k.startswith("_")},
"time_ms": round(t, 3),
"speedup": round(speedup, 4),
"smem_est": point.get("_smem_est", 0),
})
marker = ""
if speedup > best_speedup:
best_speedup = speedup
best_point = point
marker = ""
if (i + 1) % 5 == 0 or marker:
print(f" [{i+1}/{len(valid)}] {format_point(point):45s} "
f"{t:8.2f}ms {speedup:6.3f}x{marker}")
# Sort by speedup
results.sort(key=lambda r: -r["speedup"])
print(f"\n{'='*70}")
print(f"TOP 5 for {target}:")
for j, r in enumerate(results[:5]):
print(f" #{j+1}: {r['point']} {r['time_ms']}ms {r['speedup']}x")
if output_dir:
os.makedirs(output_dir, exist_ok=True)
path = os.path.join(output_dir, f"triton_{target}.json")
with open(path, "w") as f:
json.dump({
"target": target,
"hardware": HW,
"baseline_time_ms": round(baseline_time, 3),
"results": results[:20], # top 20
}, f, indent=2)
print(f" Saved: {path}")
return results
def main():
p = argparse.ArgumentParser(
description="BI-V100 Triton JIT parameter benchmark (REAL injection)")
p.add_argument("--target", required=True,
choices=["prefill", "flash_attn", "moe", "smem", "all"],
help="Which tunable surface to benchmark")
p.add_argument("--dry-run", action="store_true",
help="Just show valid combos, don't run")
p.add_argument("-o", "--output", default=None,
help="Output directory for results JSON")
p.add_argument("--smem-limit", type=int, default=None,
help="Override SMEM limit (49152 or 32768)")
args = p.parse_args()
if args.smem_limit:
HW["smem_per_block"] = args.smem_limit
targets = list(SEARCH_SPACES.keys()) if args.target == "all" else [args.target]
for target in targets:
run_benchmark(target, args.dry_run, args.output)
if __name__ == "__main__":
main()