hakmem/core/hakmem_tiny_config.c

/**
 * hakmem_tiny_config.c
 *
 * Implementation of centralized Tiny configuration constants
 */

#include "hakmem_tiny_config.h"

// ============================================================================
// Fast Cache Configuration
// ============================================================================

// Factory defaults ("aggressive") – mutable at runtime
// Phase 10: Aggressive cache sizing to maximize TLS hit rate
// Hot classes (C0-C3) get 2-4x larger caches to reduce backend transitions
static const uint16_t k_fast_cap_defaults_factory[TINY_NUM_CLASSES] = {
    512,   // Class 0:   8B (2x increase: hot class)
    512,   // Class 1:  16B (2x increase: hot class)
    512,   // Class 2:  32B (2x increase: hot class)
    384,   // Class 3:  64B (3x increase: hot class)
    256,   // Class 4: 128B (2x increase: medium class)
    384,   // Class 5: 256B (1.7x increase: bench-optimized)
    192,   // Class 6: 512B (1.5x increase)
    96     // Class 7: 1KB (2x increase: reduce superslab reliance)
};

uint16_t g_fast_cap_defaults[TINY_NUM_CLASSES] = {
    512, 512, 512, 384, 256, 384, 192, 96
};

void tiny_config_reset_defaults(void) {
    for (int i = 0; i < TINY_NUM_CLASSES; i++) {
        g_fast_cap_defaults[i] = k_fast_cap_defaults_factory[i];
    }
}

// ============================================================================
// TLS Magazine Configuration
// ============================================================================

// Default TLS magazine capacities per class
// Phase 10: Aggressive cache sizing for hot classes (C0-C3)
// Goal: Maximize TLS hit rate, reduce backend transitions
int tiny_default_cap(int class_idx) {
    switch (class_idx) {
        case 0: return 512;   // 8B  (4x increase: hot class)
        case 1: return 512;   // 16B (4x increase: hot class)
        case 2: return 512;   // 32B (4x increase: hot class)
        case 3: return 384;   // 64B (3x increase: hot class)
        case 4: return 192;   // 128B (2x increase: medium class)
        case 5: return 256;   // 256B (2x increase: medium class)
        case 6: return 192;   // 512B (1.5x increase)
        default: return 128;  // 1KB (2x increase)
    }
}

// Alias for tiny_default_cap
int tiny_mag_default_cap(int class_idx) {
    return tiny_default_cap(class_idx);
}

// Maximum allowed TLS magazine capacities per class
// Phase 10: Raise ceilings to allow aggressive cache growth
int tiny_cap_max_for_class(int class_idx) {
    switch (class_idx) {
        case 0: return 4096;   // 8B  (2x increase: allow massive caching)
        case 1: return 4096;   // 16B (4x increase: hot class)
        case 2: return 2048;   // 32B (2.67x increase: hot class)
        case 3: return 1536;   // 64B (3x increase: hot class)
        case 4: return 512;    // 128B (3.2x increase: medium class)
        case 5: return 768;    // 256B (3x increase: medium class)
        case 6: return 384;    // 512B (3x increase)
        default: return 256;   // 1KB (4x increase)
    }
}