feat! Mimalloc as the default allocator (#434)

This change integrates mimalloc as the default memory allocator for Regorus,
delivering significant performance improvements across all evaluation modes
and language bindings.

Technical Implementation:
- Build mimalloc in vendored mode from C sources (following QSharp approach)
- Implement GlobalAlloc trait for seamless Rust integration
- Add optional 'mimalloc' feature flag for conditional compilation
- Add comprehensive ACI benchmarks to measure evaluation performance

Performance Impact:

Rust Engine Evaluation:
- Single-threaded: ~29% improvement (423 vs 328 Kelem/s)
- Multi-threaded: Better scaling with reduced thread contention
- Fresh engines: ~24% improvement (56 vs 45 Kelem/s)

Rust Compiled Policy Evaluation:
- Single-threaded: ~41% improvement (426 vs 303 Kelem/s)
- Multi-threaded: Improved allocation efficiency under contention
- Fresh compilation: ~26% improvement (53 vs 42 Kelem/s)

C# FFI Bindings:
- Engine evaluation: ~27% improvement (279 vs 219 Kelem/s)
- Compiled policies: ~29% improvement (273 vs 211 Kelem/s)
- Better threading characteristics through improved underlying allocation

Key Benefits:
- Reduced allocation-related contention in multi-threaded scenarios
- More consistent performance across different thread counts
- Improved memory allocation efficiency for both native Rust and FFI workloads
- Better scaling characteristics for production deployments

The mimalloc integration provides substantial performance gains while
maintaining full compatibility with existing code through feature flags.

Reference: QSharp allocator implementation
(https://github.com/microsoft/qsharp/tree/main/source/allocator)

Fixes #297

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
This commit is contained in:
Anand Krishnamoorthi
2025-08-25 15:01:38 -05:00
committed by GitHub
parent 6c5338228b
commit 2a0b4ae6b5
59 changed files with 17039 additions and 328 deletions
@@ -5,6 +5,7 @@
- **CPU**: 16 cores
- **Architecture**: ARM64 (aarch64-apple-darwin)
- **Rust Version**: 1.82.0
- **Allocator**: mimalloc (default allocator)
- **Benchmark Framework**: Criterion.rs
- **Test Data**: 20,000 inputs per evaluation (1000 per thread)
- **Policy**: Complex authorization policy with nested rules
@@ -25,111 +26,135 @@ The compiled policy evaluation benchmark tests Regorus compiled policy performan
### Compiled Shared Policies, Cloned Inputs (Best Performance)
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 3.30 | 303 |
| 2 | 8.53 | 234 |
| 4 | 18.78 | 213 |
| 6 | 32.35 | 186 |
| 8 | 73.12 | 109 |
| 10 | 108.97 | 92 |
| 12 | 145.56 | 82 |
| 14 | 196.14 | 71 |
| 16 | 248.77 | 64 |
| 18 | 290.01 | 62 |
| 20 | 317.16 | 63 |
| 22 | 348.83 | 63 |
| 24 | 361.05 | 66 |
| 26 | 389.70 | 67 |
| 28 | 418.66 | 67 |
| 30 | 444.40 | 68 |
| 32 | 476.53 | 67 |
| 1 | 2.35 | 426 |
| 2 | 5.36 | 373 |
| 4 | 11.70 | 342 |
| 6 | 20.33 | 295 |
| 8 | 43.26 | 185 |
| 10 | 61.93 | 162 |
| 12 | 79.30 | 151 |
| 14 | 94.45 | 148 |
| 16 | 113.39 | 141 |
| 18 | 154.41 | 117 |
| 20 | 184.37 | 108 |
| 22 | 204.00 | 108 |
| 24 | 220.45 | 109 |
| 26 | 237.07 | 110 |
| 28 | 252.58 | 111 |
| 30 | 273.57 | 110 |
| 32 | 292.69 | 109 |
### Compiled Shared Policies, Fresh Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 4.51 | 222 |
| 2 | 9.77 | 205 |
| 4 | 23.36 | 171 |
| 6 | 38.12 | 157 |
| 8 | 85.02 | 94 |
| 10 | 133.66 | 75 |
| 12 | 180.46 | 66 |
| 14 | 238.23 | 59 |
| 16 | 318.78 | 50 |
| 18 | 353.15 | 51 |
| 20 | 389.29 | 51 |
| 22 | 459.61 | 48 |
| 24 | 507.62 | 47 |
| 26 | 539.43 | 48 |
| 28 | 554.99 | 50 |
| 30 | 625.57 | 48 |
| 32 | 690.55 | 46 |
| 1 | 3.34 | 299 |
| 2 | 7.29 | 274 |
| 4 | 15.19 | 263 |
| 6 | 24.90 | 241 |
| 8 | 49.22 | 163 |
| 10 | 68.45 | 146 |
| 12 | 86.55 | 139 |
| 14 | 104.77 | 134 |
| 16 | 136.07 | 118 |
| 18 | 169.05 | 106 |
| 20 | 198.25 | 101 |
| 22 | 217.05 | 101 |
| 24 | 234.75 | 102 |
| 26 | 254.53 | 102 |
| 28 | 276.06 | 101 |
| 30 | 296.12 | 101 |
| 32 | 318.81 | 100 |
### Compiled Per Iteration, Cloned Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 22.68 | 44 |
| 2 | 47.99 | 42 |
| 4 | 108.09 | 37 |
| 6 | 167.62 | 36 |
| 8 | 283.17 | 28 |
| 10 | 418.25 | 24 |
| 12 | 546.24 | 22 |
| 14 | 688.79 | 20 |
| 16 | 951.72 | 17 |
| 18 | 1060.20 | 17 |
| 20 | 1223.60 | 16 |
| 22 | 1342.50 | 16 |
| 24 | 1445.70 | 17 |
| 26 | 1676.50 | 15 |
| 28 | 1765.20 | 16 |
| 30 | 1939.00 | 15 |
| 32 | 2197.30 | 15 |
| 1 | 18.11 | 55 |
| 2 | 36.89 | 54 |
| 4 | 75.46 | 53 |
| 6 | 114.66 | 52 |
| 8 | 152.80 | 52 |
| 10 | 192.17 | 52 |
| 12 | 232.32 | 52 |
| 14 | 301.47 | 46 |
| 16 | 380.36 | 42 |
| 18 | 424.64 | 42 |
| 20 | 484.76 | 41 |
| 22 | 531.62 | 41 |
| 24 | 582.88 | 41 |
| 26 | 631.39 | 41 |
| 28 | 671.99 | 42 |
| 30 | 717.65 | 42 |
| 32 | 766.05 | 42 |
### Compiled Per Iteration, Fresh Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 23.95 | 42 |
| 2 | 49.53 | 40 |
| 4 | 116.42 | 34 |
| 6 | 197.35 | 30 |
| 8 | 293.04 | 27 |
| 10 | 385.90 | 26 |
| 12 | 508.82 | 24 |
| 14 | 679.23 | 21 |
| 16 | 913.02 | 18 |
| 18 | 1075.90 | 17 |
| 20 | 1209.80 | 17 |
| 22 | 1358.90 | 16 |
| 24 | 1523.90 | 16 |
| 26 | 1700.20 | 15 |
| 28 | 1966.90 | 14 |
| 30 | 2179.30 | 14 |
| 32 | 2327.70 | 14 |
| 1 | 19.07 | 52 |
| 2 | 38.89 | 51 |
| 4 | 79.52 | 50 |
| 6 | 120.89 | 50 |
| 8 | 161.08 | 50 |
| 10 | 202.37 | 49 |
| 12 | 244.04 | 49 |
| 14 | 316.66 | 44 |
| 16 | 398.02 | 40 |
| 18 | 449.54 | 40 |
| 20 | 500.57 | 40 |
| 22 | 557.97 | 39 |
| 24 | 605.71 | 40 |
| 26 | 656.88 | 40 |
| 28 | 710.03 | 39 |
| 30 | 741.09 | 40 |
| 32 | 801.26 | 40 |
## Analysis
The compiled policy benchmark demonstrates the following performance characteristics:
The compiled policy benchmark demonstrates the following performance characteristics with mimalloc as the default allocator:
1. **Best Performance**: Compiled shared policies with cloned inputs provide the highest throughput
2. **Compilation Impact**:
- Pre-compiled policies: Significantly faster than per-iteration compilation
- Per-iteration compilation: Major overhead (~7x slower than pre-compiled)
3. **Scaling Patterns**:
- Per-iteration compilation: Major overhead (~7-8x slower than pre-compiled)
3. **Scaling Patterns with mimalloc**:
- Best throughput achieved at 1 thread for shared policy configurations
- Higher thread counts show performance degradation due to contention
- mimalloc provides better thread scaling characteristics compared to the default allocator
- Higher thread counts show performance degradation due to contention, but less severe with mimalloc
- Per-iteration compilation shows poor scaling across all thread counts
4. **Input Processing**: Fresh inputs add ~25-30% overhead across all configurations
5. **Thread Performance**:
4. **Input Processing**: Fresh inputs add ~30% overhead across all configurations
5. **Thread Performance with mimalloc**:
- Peak performance at 1 thread for most configurations
- Reasonable performance maintained up to 12-16 threads for shared policies
- Compiled policies show better thread scaling than per-iteration compilation
- mimalloc helps reduce allocation-related contention in multi-threaded scenarios
## Comparison with Engine Evaluation
| Configuration | Compiled Policy (1 thread) | Engine Evaluation (1 thread) | Performance Ratio |
|:---------------------|:--------------------------------|:--------------------------------|------------------:|
| Shared/Cloned | Best performance | Higher throughput | 0.67x-0.92x |
| Shared/Fresh | ~27% reduction from optimal | ~30% reduction from optimal | 0.62x-0.97x |
| Per-iteration/Cloned | ~85% reduction from optimal | ~86% reduction from optimal | 0.80x-0.98x |
| Per-iteration/Fresh | ~86% reduction from optimal | ~87% reduction from optimal | 0.78x-1.00x |
### Multi-Thread Performance Comparison
| Configuration | 1 Thread (Kelem/s) | 4 Threads (Kelem/s) | 8 Threads (Kelem/s) |
|:---------------------|:-------------------|:--------------------|:--------------------|
| | CP / EE | CP / EE | CP / EE |
| Shared/Cloned | 426 / 423 | 342 / 406 | 185 / 341 |
| Shared/Fresh | 299 / 309 | 263 / 297 | 163 / 266 |
| Per-iteration/Cloned | 55 / 56 | 53 / 54 | 52 / 53 |
| Per-iteration/Fresh | 52 / 53 | 50 / 51 | 50 / 51 |
### Threading Efficiency Analysis
| Configuration | Low Contention (1-4t) | Medium Contention (6-12t) | High Contention (16+t) |
|:---------------------|:----------------------|:--------------------------|:-----------------------|
| | Avg CP / EE | Avg CP / EE | Avg CP / EE |
| Shared/Cloned | 384 / 414 | 203 / 329 | 123 / 250 |
| Shared/Fresh | 284 / 302 | 176 / 235 | 108 / 201 |
| Per-iteration/Cloned | 54 / 55 | 50 / 52 | 42 / 42 |
| Per-iteration/Fresh | 51 / 52 | 47 / 50 | 40 / 40 |
The compiled policy evaluation shows performance characteristics that are generally comparable to engine evaluation, though with some notable differences. While single-threaded performance is very close between the systems, there are observable impacts from the compilation approach that become more apparent under different threading scenarios.
**Key Observations:**
- **Single-threaded performance**: Very close parity between systems, though results may vary between runs
- **Threading behavior**: Engine evaluation demonstrates better scaling characteristics under higher thread contention (4+ threads)
- **Multi-threaded impact**: Compiled policies show more pronounced performance degradation under thread contention in shared policy configurations
- **Contention resistance**: Per-iteration compilation shows more consistent (though lower absolute) performance across thread counts
- **Optimal usage**: Both systems achieve best results with minimal threading (1-4 threads), though engine evaluation maintains better performance at higher thread counts for shared configurations
@@ -5,6 +5,7 @@
- **CPU**: 16 cores
- **Architecture**: ARM64 (aarch64-apple-darwin)
- **Rust Version**: 1.82.0
- **Allocator**: mimalloc (default allocator)
- **Benchmark Framework**: Criterion.rs
- **Test Data**: 20,000 inputs per evaluation (1000 per thread)
- **Policy**: Complex authorization policy with nested rules
@@ -25,101 +26,102 @@ The engine evaluation benchmark tests Regorus policy evaluation performance acro
### Cloned Engines, Cloned Inputs (Best Performance)
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 3.05 | 328 |
| 2 | 7.46 | 268 |
| 4 | 16.10 | 248 |
| 6 | 25.94 | 231 |
| 8 | 50.18 | 159 |
| 10 | 80.27 | 125 |
| 12 | 106.31 | 113 |
| 14 | 137.31 | 102 |
| 16 | 163.91 | 98 |
| 18 | 182.06 | 99 |
| 20 | 191.36 | 105 |
| 22 | 201.51 | 109 |
| 24 | 217.65 | 110 |
| 26 | 228.11 | 114 |
| 28 | 248.17 | 113 |
| 30 | 264.15 | 114 |
| 32 | 314.27 | 102 |
| 1 | 2.36 | 423 |
| 2 | 4.85 | 412 |
| 4 | 9.86 | 406 |
| 6 | 15.02 | 399 |
| 8 | 23.46 | 341 |
| 10 | 33.34 | 300 |
| 12 | 40.69 | 295 |
| 14 | 48.26 | 290 |
| 16 | 58.61 | 273 |
| 18 | 77.35 | 233 |
| 20 | 86.74 | 231 |
| 22 | 94.17 | 234 |
| 24 | 102.58 | 234 |
| 26 | 110.17 | 236 |
| 28 | 118.97 | 235 |
| 30 | 126.54 | 237 |
| 32 | 135.89 | 235 |
### Cloned Engines, Fresh Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 4.36 | 229 |
| 2 | 10.34 | 194 |
| 4 | 21.98 | 182 |
| 6 | 34.05 | 176 |
| 8 | 66.47 | 120 |
| 10 | 100.78 | 99 |
| 12 | 141.69 | 85 |
| 14 | 188.53 | 74 |
| 16 | 261.27 | 61 |
| 18 | 285.29 | 63 |
| 20 | 312.14 | 64 |
| 22 | 329.42 | 67 |
| 24 | 347.97 | 69 |
| 26 | 370.24 | 70 |
| 28 | 394.75 | 71 |
| 30 | 419.30 | 72 |
| 32 | 433.58 | 74 |
| 1 | 3.24 | 309 |
| 2 | 6.57 | 304 |
| 4 | 13.47 | 297 |
| 6 | 20.42 | 294 |
| 8 | 30.01 | 266 |
| 10 | 40.99 | 244 |
| 12 | 49.99 | 240 |
| 14 | 60.09 | 233 |
| 16 | 73.95 | 216 |
| 18 | 95.94 | 188 |
| 20 | 105.24 | 190 |
| 22 | 114.30 | 192 |
| 24 | 124.67 | 193 |
| 26 | 134.76 | 193 |
| 28 | 145.16 | 193 |
| 30 | 155.23 | 193 |
| 32 | 165.42 | 193 |
### Fresh Engines, Cloned Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 22.39 | 45 |
| 2 | 49.22 | 41 |
| 4 | 98.09 | 41 |
| 6 | 160.21 | 37 |
| 8 | 281.26 | 28 |
| 10 | 413.61 | 24 |
| 12 | 578.15 | 21 |
| 14 | 746.34 | 19 |
| 16 | 961.44 | 17 |
| 18 | 1127.70 | 16 |
| 20 | 1248.40 | 16 |
| 22 | 1386.90 | 16 |
| 24 | 1559.70 | 15 |
| 26 | 1736.30 | 15 |
| 28 | 1891.80 | 15 |
| 30 | 2077.00 | 14 |
| 32 | 2289.30 | 14 |
| 1 | 17.88 | 56 |
| 2 | 36.32 | 55 |
| 4 | 74.45 | 54 |
| 6 | 112.95 | 53 |
| 8 | 150.24 | 53 |
| 10 | 189.61 | 53 |
| 12 | 228.25 | 53 |
| 14 | 297.37 | 47 |
| 16 | 373.61 | 43 |
| 18 | 426.46 | 42 |
| 20 | 477.80 | 42 |
| 22 | 523.00 | 42 |
| 24 | 570.74 | 42 |
| 26 | 619.92 | 42 |
| 28 | 670.24 | 42 |
| 30 | 717.47 | 42 |
| 32 | 748.25 | 43 |
### Fresh Engines, Fresh Inputs
| Threads | Total Evaluation Time (ms) | Throughput (Kelem/s) |
|--------:|---------------------------:|---------------------:|
| 1 | 23.63 | 42 |
| 2 | 48.82 | 41 |
| 4 | 102.32 | 39 |
| 6 | 160.09 | 37 |
| 8 | 271.21 | 29 |
| 10 | 397.39 | 25 |
| 12 | 489.09 | 25 |
| 14 | 670.33 | 21 |
| 16 | 884.83 | 18 |
| 18 | 1044.00 | 17 |
| 20 | 1174.20 | 17 |
| 22 | 1330.40 | 17 |
| 24 | 1480.90 | 16 |
| 26 | 1679.50 | 15 |
| 28 | 1873.90 | 15 |
| 30 | 2070.90 | 14 |
| 32 | 2325.40 | 14 |
| 1 | 18.69 | 53 |
| 2 | 38.03 | 53 |
| 4 | 77.82 | 51 |
| 6 | 118.30 | 51 |
| 8 | 157.65 | 51 |
| 10 | 197.97 | 51 |
| 12 | 239.05 | 50 |
| 14 | 310.06 | 45 |
| 16 | 391.36 | 41 |
| 18 | 441.63 | 41 |
| 20 | 495.88 | 40 |
| 22 | 543.69 | 40 |
| 24 | 591.51 | 41 |
| 26 | 645.98 | 40 |
| 28 | 697.37 | 40 |
| 30 | 749.37 | 40 |
| 32 | 784.63 | 41 |
## Analysis
The benchmark results demonstrate the following performance characteristics:
The benchmark results demonstrate the following performance characteristics with mimalloc as the default allocator:
1. **Best Performance**: Cloned engines with cloned inputs consistently deliver the highest throughput
2. **Configuration Performance Hierarchy**:
- Cloned engines, cloned inputs: Best performance (optimal configuration)
- Cloned engines, fresh inputs: ~30% reduction from optimal
- Fresh engines, cloned inputs: ~86% reduction from optimal
- Cloned engines, fresh inputs: ~27% reduction from optimal
- Fresh engines, cloned inputs: ~87% reduction from optimal
- Fresh engines, fresh inputs: ~87% reduction from optimal
3. **Scaling Patterns**:
- Performance degrades with increased thread count due to contention
3. **Scaling Patterns with mimalloc**:
- Performance degrades with increased thread count due to contention, but mimalloc provides better thread scaling characteristics
- Best throughput achieved at 1 thread for cloned engine configurations
- Fresh engine configurations show poor scaling across all thread counts
- The use of mimalloc as the default allocator has improved multi-threaded performance and reduced contention
4. **Engine Creation Overhead**: Fresh engine creation is a significant performance bottleneck (~7-8x slower than cloned engines)
5. **Input Processing**: Fresh input generation adds moderate overhead (~30% impact compared to cloned inputs)
6. **Thread Contention**: Performance degradation occurs with higher thread counts across all configurations
5. **Input Processing**: Fresh input generation adds moderate overhead (~27% impact compared to cloned inputs)
6. **Thread Contention**: Performance degradation occurs with higher thread counts across all configurations, though mimalloc helps mitigate some allocation-related contention