KernelClaw: A Multi-Agent Framework for GPU Kernel Optimization with Dual-Memory Mechanisms
Authors: Qitong Sun, Jun Han, Tianlin Li, Zhe Tang, Sheng Chen, Fei Yang, Aishan Liu, Xianglong Liu, Yang Liu
Organizations: School of Computer Science and Engineering, Beihang University, China · Zhejiang Lab, China · Nanyang Technological University, Singapore
Improving GPU kernel efficiency is crucial for efficient AI systems. Recent work has explored leveraging large language models (LLMs) for GPU kernel generation and optimization. However, existing LLM-based kernel optimization pipelines typically rely on opaque, implicitly learned heuristics within the LLMs to determine optimization strategies. This leads to inefficient trial-and-error and weakly interpretable optimizations. Our key insight is to replace implicit heuristics with expert optimization knowledge that is aware of task trajectories. Specifically, we present KernelClaw, a multi-agent framework with a dual-level memory architecture. KernelClaw operates by coordinating agents with long-term memory of reusable expert knowledge and short-term memory to prevent repetitive backtracking. On KernelBench Levels 1-3, KernelClaw achieves a 100% success rate and average speedups of 6.98x, 7.89x, and 1.94x over Torch Eager on Levels 1, 2, and 3, respectively, outperforming prior baselines. Code is available at https://github.com/0satan0/KernelMem/.
Figures & tables
Figure 1: Overview of KernelClaw
Method
Level 1
Level 2
Level 3
Success ↑
Fast 1 ↑
Speedup ↑
Success ↑
Fast 1 ↑
Speedup ↑
Success ↑
Fast 1 ↑
Speedup ↑
Torch Compile(default)
1.00
0.61
1.51
1.00
0.76
1.22
1.00
0.68
1.40
Torch Compile(max-autotune)
1.00
0.68
1.42
1.00
0.86
1.29
1.00
0.82
1.38
Kevin-32B
0.69
0.04
0.84
0.67
0.08
0.40
0.46
0.02
0.32
AutoTriton
0.36
0.09
1.20
0.55
0.22
0.96
0.56
0.26
0.83
Astra
0.95
0.43
1.48
0.98
0.73
0.99
0.93
0.35
0.90
Table 1: Success, Fast 1 and Speedup Results. Success is the percentage of tasks for which a method generates a kernel that compiles and passes correctness verification. Fast 1 is the percentage of tasks whose generated kernel is at least as fast as the Torch baseline. Speedup is the average runtime speedup over Torch Eager. KernelClaw achieves the best overall performance, matching the highest success rate and Fast 1 rate while delivering the largest speedup across all levels among all compared baselines.
Method
Level 1
Level 2
Level 3
Success ↑
Fast 1 ↑
Speedup ↑
Success ↑
Fast 1 ↑
Speedup ↑
Success ↑
Fast 1 ↑
Speedup ↑
w/o memory
0.96
0.46
1.52
0.98
0.75
1.05
0.94
0.36
0.95
w/o ST memory
0.96
0.51
3.53
0.98
0.85
2.42
0.94
0.70
1.78
w/o LT memory
1.00
0.55
1.77
1.00
1.00
1.18
1.00
0.79
1.04
KernelClaw
1.00
0.74
6.98
1.00
1.00
7.89
1.00
0.88
1.94
Table 2: Ablation Results. We ablate memory components: Long-term memory stores retrievable kernel optimization knowledge for reusable and explainable method selection, while Short-term memory records per-task optimization/repair trajectories to stabilize multi-round refinement. Removing either memory reduces Fast 1 and Speedup, confirming both components are critical to KernelClaw ’s improvements.
Result
Level 1
Level 2
Level 3
Original
6.98 ×
7.89 ×
1.94 ×
Audited
3.47 ×
3.92 ×
1.94 ×
Table 3: Speedup of KernelClaw before and after excluding two anomalous kernels.
Appendix figures & tables14 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 2: The short-term memory for the current repair round
Figure 3: The short-term memory for the current optimization round
Figure 4: Speedup distribution on 100 tasks at Level 1.
Figure 5: Speedup distribution on 100 tasks at Level 2.
Figure 6: Speedup distribution on 50 tasks at Level 3.
KernelBench
Success ↑
Fast 1 ↑
Speedup ↑
Level 1
0.51
0.10
0.60
Level 2
0.07
0.00
0.01
Level 3
0.04
0.00
0.03
Appendix
Table 4: Results with Qwen3-30B-A3B under 15-round optimization budget.
Stage / Outcome
Count
Rate
Sampled tasks
30
–
Valid seed kernels
21 / 30
70.0%
Matched expert methods
17 / 21
81.0%
Improved CUDABench-Score
14 / 17
82.4%
Improved both Score and speedup
12 / 17
70.6%
Failed after matched methods
3 / 17
17.6%
Appendix
Table 5: Statistics on 30 randomly sampled CUDABench tasks.
Task
Matched Method
Seed → Best
Δ
Relative
w/o Expert Methods Δ
358
CMP_Irregular_Compute_S2 ; ML_REUSE
0.174 → 0.727
+0.553
+318%
+0.097
254
MBW_* ; ML_FALLBACK
0.521 → 0.916
+0.395
+76%
+0.171
119
GEMM ; CUBLASLT ; TILING
0.211 → 0.437
+0.226
+107%
+0.000
79
CMP_Irregular_Compute_S2
0.150 → 0.351
+0.201
+134%
+0.061
Appendix
Table 6: Representative CUDABench cases improved by matched optimization methods. The last column reports the CUDABench-Score improvement obtained when expert-method retrieval is disabled.
Method
Input ↓
Output ↓
Total ↓
CudaForge
51k
20k
71k
Astra
56k
21k
77k
PRAGMA
53k
21k
74k
AdaExplore
84k
9k
93k
OpenEvolve
58k
12k
70k
EGG
55k
22k
77k
Appendix
Table 7: Average token consumption per task using GPT-5.1 under a unified budget of 15 optimization rounds. All values are reported in thousands of tokens.
Method
L1
L2
L3
Avg.
w/o short-term memory
67.9%
74.7%
70.4%
71.0%
KernelClaw
73.2%
78.2%
72.1%
74.5%
Appendix
Table 8: Percentage of rounds devoted to performance optimization under the same 15-round budget. Higher values indicate that a larger fraction of the trajectory is used to improve already correct kernels rather than repair invalid ones.
Outcome
Count
Rate
Sampled tasks
30
–
Valid seed kernels
30 / 30
100.0%
Tasks with matched expert methods
29 / 30
96.7%
Tasks improved by KernelClaw
23 / 29
79.3%
Tasks not improved by KernelClaw
6 / 29
20.7%
Tasks improved w/o expert methods
11 / 29
37.9%
Appendix
Table 9: Optimization outcomes on 30 randomly sampled TritonBench-G tasks.
Task
Matched Expert Methods
w/o Expert Methods
KernelClaw
Absolute Gain
Relative Gain
geglu_tanh_triton
Tune_Num_Warps ; Constexpr_Block_Tuning
4.71 ×
7.33 ×
+2.62 ×
+55.6%
batched_vecmat_mult
Rewrite_Mulsum_to_tl_dot ; Enable_tl_dot_tf32
1.25 ×
6.07 ×
+4.82 ×
+385.6%
dequantize_matmul
Quant_Dequant_Matmul ; Tune_Num_Warps
0.99 ×
4.55 ×
+3.56 ×
+359.6%
layernorm_fwd_triton
tl_rsqrt ; Welford_Layernorm
1.28 ×
1.80 ×
+0.52 ×
+40.6%
Mean over 30 tasks
–
1.38 ×
1.90 ×
+0.52 ×
+37.7%
Appendix
Table 10: Representative TritonBench-G tasks improved by the expert methods retrieved by KernelClaw. Speedup is measured relative to the original Triton seed kernel.
GPU
Level
Success ↑
Fast 1 ↑
Speedup ↑
A40
Level 1
1.00
0.68
5.86 ×
Level 2
1.00
0.98
6.14 ×
Level 3
1.00
0.70
1.81 ×
RTX 4090
Level 1
1.00
0.71
5.48 ×
Level 2
1.00
0.94
5.60 ×
Level 3
1.00
0.68
1.71 ×
Appendix
Table 11: Cross-GPU evaluation of KernelClaw on KernelBench. Speedup is measured relative to Torch Eager on the corresponding GPU.
Method
Success ↑
Geo. Mean Speedup ↑
μ CUTLASS+SOL
1.00
1.99 ×
KernelClaw
1.00
2.21 ×
Appendix
Table 12: Controlled comparison with μ CUTLASS+SOL on the same 59 KernelBench tasks under GPT-5.1 and a 15-round optimization budget.