141b121e9c
Key Changes: - Reduced static capacity from 16 to 12 SuperSlabs per class - Fixed prefill threshold from hardcoded 4 to match capacity (12) - Updated environment variable clamping to [1,12] - This allows warm pool to actually utilize its full capacity Performance: - Baseline (post-unified-cache-opt): 4.76M ops/s - After Phase 1: 4.84M ops/s - Improvement: +1.6% (expected +15-20%) Note: Actual improvement lower than expected because the warm pool bottleneck is only part of the overall allocation path. Unified cache optimization (+14.9%) already addressed much of the registry scan overhead. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
80 lines
2.8 KiB
C
80 lines
2.8 KiB
C
// warm_pool_prefill_box.h - Warm Pool Prefill Box
|
|
// Purpose: Secondary prefill optimization - load multiple superlslabs when pool is empty
|
|
// License: MIT
|
|
// Date: 2025-12-04
|
|
|
|
#ifndef HAK_WARM_POOL_PREFILL_BOX_H
|
|
#define HAK_WARM_POOL_PREFILL_BOX_H
|
|
|
|
#include <stdint.h>
|
|
#include "../hakmem_tiny_config.h"
|
|
#include "../hakmem_tiny_superslab.h"
|
|
#include "../tiny_tls.h"
|
|
#include "../front/tiny_warm_pool.h"
|
|
#include "../box/warm_pool_stats_box.h"
|
|
|
|
// Forward declarations
|
|
extern __thread TinyTLSSlab g_tls_slabs[TINY_NUM_CLASSES];
|
|
extern SuperSlab* superslab_refill(int class_idx);
|
|
|
|
// ============================================================================
|
|
// Warm Pool Prefill Policy
|
|
// ============================================================================
|
|
|
|
// Prefill budget: How many additional SuperSlabs to load when pool is empty
|
|
// - If pool is empty, load PREFILL_BUDGET extra slabs to build working set
|
|
// - This avoids repeated registry scans on rapid cache misses
|
|
// - Phase 2: Keep at 2 (increasing to 4 caused contention regression -1.5%)
|
|
#define WARM_POOL_PREFILL_BUDGET 2
|
|
|
|
// ============================================================================
|
|
// Warm Pool Prefill API (Inline for Cold Path)
|
|
// ============================================================================
|
|
|
|
// Perform secondary prefill when warm pool becomes empty
|
|
// Called from unified_cache_refill() cold path when warm_pool_count() == 0
|
|
//
|
|
// Algorithm:
|
|
// 1. Check if pool is empty
|
|
// 2. If yes, load PREFILL_BUDGET additional superlslabs via superslab_refill
|
|
// 3. Push all but the last to warm pool
|
|
// 4. Return the last one for immediate carving (in tls->ss)
|
|
//
|
|
// Returns: 0 on success, -1 if superslab_refill fails
|
|
//
|
|
// Performance: Only triggered when pool is empty, cold path cost
|
|
//
|
|
static inline int warm_pool_do_prefill(int class_idx, TinyTLSSlab* tls) {
|
|
int budget = (tiny_warm_pool_count(class_idx) == 0) ? WARM_POOL_PREFILL_BUDGET : 1;
|
|
|
|
while (budget > 0) {
|
|
if (!tls->ss) {
|
|
// Need to load a new SuperSlab
|
|
if (!superslab_refill(class_idx)) {
|
|
return -1; // Error: cannot allocate new SuperSlab
|
|
}
|
|
tls = &g_tls_slabs[class_idx]; // Reload TLS after refill
|
|
}
|
|
|
|
// Check SuperSlab validity
|
|
if (!(tls->ss && tls->ss->magic == SUPERSLAB_MAGIC)) {
|
|
break;
|
|
}
|
|
|
|
if (budget > 1) {
|
|
// Prefill mode: push to pool and load another
|
|
tiny_warm_pool_push(class_idx, tls->ss);
|
|
warm_pool_record_prefilled(class_idx);
|
|
tls->ss = NULL; // Force next iteration to refill
|
|
budget--;
|
|
} else {
|
|
// Final slab: keep in TLS for immediate carving
|
|
budget = 0;
|
|
}
|
|
}
|
|
|
|
return 0; // Success
|
|
}
|
|
|
|
#endif // HAK_WARM_POOL_PREFILL_BOX_H
|