// tiny_alloc_fast.inc.h - Box 5: Allocation Fast Path (3-4 instructions) // Purpose: Ultra-fast TLS freelist pop (inspired by System tcache & Mid-Large HAKX +171%) // Invariant: Hit rate > 95% → 3-4 instructions, Miss → refill from backend // Design: "Simple Front + Smart Back" - Front is dumb & fast, Back is smart // // Box 5-NEW: SFC (Super Front Cache) Integration // Architecture: SFC (Layer 0, 128-256 slots) → SLL (Layer 1, unlimited) → SuperSlab (Layer 2+) // Cascade Refill: SFC ← SLL (one-way, safe) // Goal: +200% performance (4.19M → 12M+ ops/s) // // Phase 2b: Adaptive TLS Cache Sizing // Hot classes grow to 2048 slots, cold classes shrink to 16 slots // Expected: +3-10% performance, -30-50% TLS cache memory overhead #pragma once #include "tiny_atomic.h" #include "hakmem_tiny.h" #include "tiny_route.h" #include "tiny_alloc_fast_sfc.inc.h" // Box 5-NEW: SFC Layer #include "tiny_region_id.h" // Phase 7: Header-based class_idx lookup #include "tiny_adaptive_sizing.h" // Phase 2b: Adaptive sizing #ifdef HAKMEM_TINY_FRONT_GATE_BOX #include "box/front_gate_box.h" #endif #include // Phase 7 Task 2: Aggressive inline TLS cache access // Enable with: make HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 #ifndef HAKMEM_TINY_AGGRESSIVE_INLINE #define HAKMEM_TINY_AGGRESSIVE_INLINE 0 #endif #if HAKMEM_TINY_AGGRESSIVE_INLINE #include "tiny_alloc_fast_inline.h" #endif // ========== Debug Counters (compile-time gated) ========== #if HAKMEM_DEBUG_COUNTERS // Refill-stage counters (defined in hakmem_tiny.c) extern unsigned long long g_rf_total_calls[]; extern unsigned long long g_rf_hit_bench[]; extern unsigned long long g_rf_hit_hot[]; extern unsigned long long g_rf_hit_mail[]; extern unsigned long long g_rf_hit_slab[]; extern unsigned long long g_rf_hit_ss[]; extern unsigned long long g_rf_hit_reg[]; extern unsigned long long g_rf_mmap_calls[]; // Publish hits (defined in hakmem_tiny.c) extern unsigned long long g_pub_mail_hits[]; extern unsigned long long g_pub_bench_hits[]; extern unsigned long long g_pub_hot_hits[]; // Free pipeline (defined in hakmem_tiny.c) extern unsigned long long g_free_via_tls_sll[]; #endif // ========== Box 5: Allocation Fast Path ========== // 箱理論の Fast Allocation 層。TLS freelist から直接 pop（3-4命令）。 // 不変条件: // - TLS freelist が非空なら即座に return (no lock, no sync) // - Miss なら Backend (Box 3: SuperSlab) に委譲 // - Cross-thread allocation は考慮しない（Backend が処理） // External TLS variables (defined in hakmem_tiny.c) extern __thread void* g_tls_sll_head[TINY_NUM_CLASSES]; extern __thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES]; // External backend functions // P0 Fix: Use appropriate refill function based on P0 status #if HAKMEM_TINY_P0_BATCH_REFILL extern int sll_refill_batch_from_ss(int class_idx, int max_take); #else extern int sll_refill_small_from_ss(int class_idx, int max_take); #endif extern void* hak_tiny_alloc_slow(size_t size, int class_idx); extern int hak_tiny_size_to_class(size_t size); extern int tiny_refill_failfast_level(void); extern const size_t g_tiny_class_sizes[]; // Global Front refill config (parsed at init; defined in hakmem_tiny.c) extern int g_refill_count_global; extern int g_refill_count_hot; extern int g_refill_count_mid; extern int g_refill_count_class[TINY_NUM_CLASSES]; // HAK_RET_ALLOC macro is now defined in core/hakmem_tiny.c // See lines 116-152 for single definition point based on HAKMEM_TINY_HEADER_CLASSIDX // ========== RDTSC Profiling (lightweight) ========== #ifdef __x86_64__ static inline uint64_t tiny_fast_rdtsc(void) { unsigned int lo, hi; __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi)); return ((uint64_t)hi << 32) | lo; } #else static inline uint64_t tiny_fast_rdtsc(void) { return 0; } #endif // Per-thread profiling counters (enable with HAKMEM_TINY_PROFILE=1) static __thread uint64_t g_tiny_alloc_hits = 0; static __thread uint64_t g_tiny_alloc_cycles = 0; static __thread uint64_t g_tiny_refill_calls = 0; static __thread uint64_t g_tiny_refill_cycles = 0; static int g_tiny_profile_enabled = -1; // -1: uninitialized static inline int tiny_profile_enabled(void) { if (__builtin_expect(g_tiny_profile_enabled == -1, 0)) { const char* env = getenv("HAKMEM_TINY_PROFILE"); g_tiny_profile_enabled = (env && *env && *env != '0') ? 1 : 0; } return g_tiny_profile_enabled; } // Print profiling results at exit static void tiny_fast_print_profile(void) __attribute__((destructor)); static void tiny_fast_print_profile(void) { if (!tiny_profile_enabled()) return; if (g_tiny_alloc_hits == 0 && g_tiny_refill_calls == 0) return; fprintf(stderr, "\n========== Box Theory Fast Path Profile ==========\n"); if (g_tiny_alloc_hits > 0) { fprintf(stderr, "[ALLOC HIT] count=%lu, avg_cycles=%lu\n", (unsigned long)g_tiny_alloc_hits, (unsigned long)(g_tiny_alloc_cycles / g_tiny_alloc_hits)); } if (g_tiny_refill_calls > 0) { fprintf(stderr, "[REFILL] count=%lu, avg_cycles=%lu\n", (unsigned long)g_tiny_refill_calls, (unsigned long)(g_tiny_refill_cycles / g_tiny_refill_calls)); } fprintf(stderr, "===================================================\n\n"); } // ========== Fast Path: TLS Freelist Pop (3-4 instructions) ========== // External SFC control (defined in hakmem_tiny_sfc.c) extern int g_sfc_enabled; // Allocation fast path (inline for zero-cost) // Returns: pointer on success, NULL on miss (caller should try refill/slow) // // Box 5-NEW Architecture: // Layer 0: SFC (128-256 slots, high hit rate) [if enabled] // Layer 1: SLL (unlimited, existing) // Cascade: SFC miss → try SLL → refill // // Assembly (x86-64, optimized): // mov rax, QWORD PTR g_sfc_head[class_idx] ; SFC: Load head // test rax, rax ; Check NULL // jne .sfc_hit ; If not empty, SFC hit! // mov rax, QWORD PTR g_tls_sll_head[class_idx] ; SLL: Load head // test rax, rax ; Check NULL // je .miss ; If empty, miss // mov rdx, QWORD PTR [rax] ; Load next // mov QWORD PTR g_tls_sll_head[class_idx], rdx ; Update head // ret ; Return ptr // .sfc_hit: // mov rdx, QWORD PTR [rax] ; Load next // mov QWORD PTR g_sfc_head[class_idx], rdx ; Update head // ret // .miss: // ; Fall through to refill // // Expected: 3-4 instructions on SFC hit, 6-8 on SLL hit static inline void* tiny_alloc_fast_pop(int class_idx) { #ifdef HAKMEM_TINY_FRONT_GATE_BOX void* out = NULL; if (front_gate_try_pop(class_idx, &out)) { return out; } return NULL; #else // Phase 7 Task 3: Profiling overhead removed in release builds // In release mode, compiler can completely eliminate profiling code #if !HAKMEM_BUILD_RELEASE uint64_t start = tiny_profile_enabled() ? tiny_fast_rdtsc() : 0; #endif // Box 5-NEW: Layer 0 - Try SFC first (if enabled) // Cache g_sfc_enabled in TLS to avoid global load on every allocation static __thread int sfc_check_done = 0; static __thread int sfc_is_enabled = 0; if (__builtin_expect(!sfc_check_done, 0)) { sfc_is_enabled = g_sfc_enabled; sfc_check_done = 1; } if (__builtin_expect(sfc_is_enabled, 1)) { void* ptr = sfc_alloc(class_idx); if (__builtin_expect(ptr != NULL, 1)) { // Front Gate: SFC hit extern unsigned long long g_front_sfc_hit[]; g_front_sfc_hit[class_idx]++; // 🚀 SFC HIT! (Layer 0) #if !HAKMEM_BUILD_RELEASE if (start) { g_tiny_alloc_cycles += (tiny_fast_rdtsc() - start); g_tiny_alloc_hits++; } #endif return ptr; } // SFC miss → try SLL (Layer 1) } // Box Boundary: Layer 1 - TLS SLL freelist の先頭を pop（envで無効化可） extern int g_tls_sll_enable; // set at init via HAKMEM_TINY_TLS_SLL if (__builtin_expect(g_tls_sll_enable, 1)) { void* head = g_tls_sll_head[class_idx]; if (__builtin_expect(head != NULL, 1)) { // CORRUPTION DEBUG: Validate TLS SLL head before popping if (__builtin_expect(tiny_refill_failfast_level() >= 2, 0)) { size_t blk = g_tiny_class_sizes[class_idx]; // Check alignment (must be multiple of block size) if (((uintptr_t)head % blk) != 0) { fprintf(stderr, "[TLS_SLL_CORRUPT] cls=%d head=%p misaligned (blk=%zu offset=%zu)\n", class_idx, head, blk, (uintptr_t)head % blk); fprintf(stderr, "[TLS_SLL_CORRUPT] TLS freelist head is corrupted!\n"); abort(); } } // Front Gate: SLL hit (fast path 3 instructions) extern unsigned long long g_front_sll_hit[]; g_front_sll_hit[class_idx]++; // CORRUPTION DEBUG: Validate next pointer before updating head void* next = *(void**)head; if (__builtin_expect(tiny_refill_failfast_level() >= 2, 0)) { size_t blk = g_tiny_class_sizes[class_idx]; if (next != NULL && ((uintptr_t)next % blk) != 0) { fprintf(stderr, "[ALLOC_POP_CORRUPT] Reading next from head=%p got corrupted next=%p!\n", head, next); fprintf(stderr, "[ALLOC_POP_CORRUPT] cls=%d blk=%zu next_offset=%zu (expected 0)\n", class_idx, blk, (uintptr_t)next % blk); fprintf(stderr, "[ALLOC_POP_CORRUPT] TLS SLL head block was corrupted (use-after-free/double-free)!\n"); abort(); } fprintf(stderr, "[ALLOC_POP] cls=%d head=%p next=%p\n", class_idx, head, next); } g_tls_sll_head[class_idx] = next; // Pop: next = *head // Optional: update count (for stats, can be disabled) if (g_tls_sll_count[class_idx] > 0) { g_tls_sll_count[class_idx]--; } #if HAKMEM_DEBUG_COUNTERS // Track TLS freelist hits (compile-time gated, zero runtime cost when disabled) g_free_via_tls_sll[class_idx]++; #endif #if !HAKMEM_BUILD_RELEASE // Debug: Track profiling (release builds skip this overhead) if (start) { g_tiny_alloc_cycles += (tiny_fast_rdtsc() - start); g_tiny_alloc_hits++; } #endif return head; } } // Fast path miss → NULL (caller should refill) return NULL; #endif } // ========== Cascade Refill: SFC ← SLL (Box Theory boundary) ========== // Cascade refill: Transfer blocks from SLL to SFC (one-way, safe) // Returns: number of blocks transferred // // Contract: // - Transfer ownership: SLL → SFC // - No circular dependency: one-way only // - Boundary clear: SLL pop → SFC push // - Fallback safe: if SFC full, stop (no overflow) static inline int sfc_refill_from_sll(int class_idx, int target_count) { int transferred = 0; uint32_t cap = g_sfc_capacity[class_idx]; while (transferred < target_count && g_tls_sll_count[class_idx] > 0) { // Check SFC capacity before transfer if (g_sfc_count[class_idx] >= cap) { break; // SFC full, stop } // Pop from SLL (Layer 1) void* ptr = g_tls_sll_head[class_idx]; if (!ptr) break; // SLL empty g_tls_sll_head[class_idx] = *(void**)ptr; g_tls_sll_count[class_idx]--; // Push to SFC (Layer 0) *(void**)ptr = g_sfc_head[class_idx]; g_sfc_head[class_idx] = ptr; g_sfc_count[class_idx]++; transferred++; } return transferred; } // ========== Refill Path: Backend Integration ========== // Refill TLS freelist from backend (SuperSlab/ACE/Learning layer) // Returns: number of blocks refilled // // Box 5-NEW Architecture: // SFC enabled: SuperSlab → SLL → SFC (cascade) // SFC disabled: SuperSlab → SLL (direct, old path) // // This integrates with existing HAKMEM infrastructure: // - SuperSlab provides memory chunks // - ACE provides adaptive capacity learning // - L25 provides mid-large integration // // Refill count is tunable via HAKMEM_TINY_REFILL_COUNT (default: 16) // - Smaller count (8-16): better for diverse workloads, faster warmup // - Larger count (64-128): better for homogeneous workloads, fewer refills static inline int tiny_alloc_fast_refill(int class_idx) { // Phase 7 Task 3: Profiling overhead removed in release builds // In release mode, compiler can completely eliminate profiling code #if !HAKMEM_BUILD_RELEASE uint64_t start = tiny_profile_enabled() ? tiny_fast_rdtsc() : 0; #endif // Phase 2b: Check available capacity before refill int available_capacity = get_available_capacity(class_idx); if (available_capacity <= 0) { // Cache is full, don't refill return 0; } // Phase 7 Task 3: Simplified refill count (cached per-class in TLS) // Previous: Complex precedence logic on every miss (5-10 cycles overhead) // Now: Simple TLS cache lookup (1-2 cycles) static __thread int s_refill_count[TINY_NUM_CLASSES] = {0}; // Simple adaptive booster: bump per-class refill size when refills are frequent. static __thread uint8_t s_refill_calls[TINY_NUM_CLASSES] = {0}; int cnt = s_refill_count[class_idx]; if (__builtin_expect(cnt == 0, 0)) { // First miss: Initialize from globals (parsed at init time) int v = HAKMEM_TINY_REFILL_DEFAULT; // Default from hakmem_build_flags.h // Precedence: per-class > hot/mid > global if (g_refill_count_class[class_idx] > 0) { v = g_refill_count_class[class_idx]; } else if (class_idx <= 3 && g_refill_count_hot > 0) { v = g_refill_count_hot; } else if (class_idx >= 4 && g_refill_count_mid > 0) { v = g_refill_count_mid; } else if (g_refill_count_global > 0) { v = g_refill_count_global; } // Clamp to sane range (min: 8, max: 256) if (v < 8) v = 8; // Minimum: avoid thrashing if (v > 256) v = 256; // Maximum: avoid excessive TLS memory s_refill_count[class_idx] = v; cnt = v; } // Phase 2b: Clamp refill count to available capacity if (cnt > available_capacity) { cnt = available_capacity; } #if HAKMEM_DEBUG_COUNTERS // Track refill calls (compile-time gated) g_rf_total_calls[class_idx]++; #endif // Box Boundary: Delegate to Backend (Box 3: SuperSlab) // This gives us ACE, Learning layer, L25 integration for free! // P0 Fix: Use appropriate refill function based on P0 status #if HAKMEM_TINY_P0_BATCH_REFILL int refilled = sll_refill_batch_from_ss(class_idx, cnt); #else int refilled = sll_refill_small_from_ss(class_idx, cnt); #endif // Lightweight adaptation: if refills keep happening, increase per-class refill. // Focus on class 7 (1024B) to reduce mmap/refill frequency under Tiny-heavy loads. if (refilled > 0) { uint8_t c = ++s_refill_calls[class_idx]; if (class_idx == 7) { // Every 4 refills, increase target by +16 up to 128 (unless overridden). if ((c & 0x03u) == 0) { int target = s_refill_count[class_idx]; if (target < 128) { target += 16; if (target > 128) target = 128; s_refill_count[class_idx] = target; } } } } else { // No refill performed (capacity full): slowly decay the counter. if (s_refill_calls[class_idx] > 0) s_refill_calls[class_idx]--; } // Phase 2b: Track refill and adapt cache size if (refilled > 0) { track_refill_for_adaptation(class_idx); } // Box 5-NEW: Cascade refill SFC ← SLL (if SFC enabled) // This happens AFTER SuperSlab → SLL refill, so SLL has blocks static __thread int sfc_check_done_refill = 0; static __thread int sfc_is_enabled_refill = 0; if (__builtin_expect(!sfc_check_done_refill, 0)) { sfc_is_enabled_refill = g_sfc_enabled; sfc_check_done_refill = 1; } if (sfc_is_enabled_refill && refilled > 0) { // Transfer half of refilled blocks to SFC (keep half in SLL for future) int sfc_target = refilled / 2; if (sfc_target > 0) { #ifdef HAKMEM_TINY_FRONT_GATE_BOX front_gate_after_refill(class_idx, refilled); #else int transferred = sfc_refill_from_sll(class_idx, sfc_target); (void)transferred; // Unused, but could track stats #endif } } #if !HAKMEM_BUILD_RELEASE // Debug: Track profiling (release builds skip this overhead) if (start) { g_tiny_refill_cycles += (tiny_fast_rdtsc() - start); g_tiny_refill_calls++; } #endif return refilled; } // ========== Combined Fast Path (Alloc + Refill) ========== // Complete fast path allocation (inline for zero-cost) // Returns: pointer on success, NULL on failure (OOM or size too large) // // Flow: // 1. TLS freelist pop (3-4 instructions) - Hit rate ~95% // 2. Miss → Refill from backend (~5% cases) // 3. Refill success → Retry pop // 4. Refill failure → Slow path (OOM or new SuperSlab allocation) // // Example usage: // void* ptr = tiny_alloc_fast(64); // if (!ptr) { // // OOM handling // } static inline void* tiny_alloc_fast(size_t size) { // 1. Size → class index (inline, fast) int class_idx = hak_tiny_size_to_class(size); if (__builtin_expect(class_idx < 0, 0)) { return NULL; // Size > 1KB, not Tiny } ROUTE_BEGIN(class_idx); // 2. Fast path: TLS freelist pop (3-4 instructions, 95% hit rate) void* ptr; #if HAKMEM_TINY_AGGRESSIVE_INLINE // Task 2: Use inline macro (save 5-10 cycles, no function call) TINY_ALLOC_FAST_POP_INLINE(class_idx, ptr); #else // Standard: Function call (preserves debugging visibility) ptr = tiny_alloc_fast_pop(class_idx); #endif if (__builtin_expect(ptr != NULL, 1)) { HAK_RET_ALLOC(class_idx, ptr); } // 3. Miss: Refill from backend (Box 3: SuperSlab) int refilled = tiny_alloc_fast_refill(class_idx); if (__builtin_expect(refilled > 0, 1)) { // Refill success → retry pop #if HAKMEM_TINY_AGGRESSIVE_INLINE TINY_ALLOC_FAST_POP_INLINE(class_idx, ptr); #else ptr = tiny_alloc_fast_pop(class_idx); #endif if (ptr) { HAK_RET_ALLOC(class_idx, ptr); } } // 4. Refill failure or still empty → slow path (OOM or new SuperSlab) // Box Boundary: Delegate to Slow Path (Box 3 backend) ptr = hak_tiny_alloc_slow(size, class_idx); if (ptr) { HAK_RET_ALLOC(class_idx, ptr); } return ptr; // NULL if OOM } // ========== Push to TLS Freelist (for free path) ========== // Push block to TLS freelist (used by free fast path) // This is a "helper" for Box 6 (Free Fast Path) // // Invariant: ptr must belong to current thread (no ownership check here) // Caller (Box 6) is responsible for ownership verification static inline void tiny_alloc_fast_push(int class_idx, void* ptr) { #ifdef HAKMEM_TINY_FRONT_GATE_BOX front_gate_push_tls(class_idx, ptr); #else // Box Boundary: Push to TLS freelist *(void**)ptr = g_tls_sll_head[class_idx]; g_tls_sll_head[class_idx] = ptr; g_tls_sll_count[class_idx]++; #endif } // ========== Statistics & Diagnostics ========== // Get TLS freelist stats (for debugging/profiling) typedef struct { int class_idx; void* head; uint32_t count; } TinyAllocFastStats; static inline TinyAllocFastStats tiny_alloc_fast_stats(int class_idx) { TinyAllocFastStats stats = { .class_idx = class_idx, .head = g_tls_sll_head[class_idx], .count = g_tls_sll_count[class_idx] }; return stats; } // Reset TLS freelist (for testing/benchmarking) // WARNING: This leaks memory! Only use in controlled test environments. static inline void tiny_alloc_fast_reset(int class_idx) { g_tls_sll_head[class_idx] = NULL; g_tls_sll_count[class_idx] = 0; } // ========== Performance Notes ========== // // Expected metrics (based on System tcache & HAKX +171% results): // - Fast path hit rate: 95%+ (workload dependent) // - Fast path latency: 3-4 instructions (1-2 cycles on modern CPUs) // - Miss penalty: ~20-50 instructions (refill from SuperSlab) // - Throughput improvement: +10-25% vs current multi-layer design // // Key optimizations: // 1. `__builtin_expect` for branch prediction (hot path first) // 2. `static inline` for zero-cost abstraction // 3. TLS variables (no atomic ops, no locks) // 4. Minimal work in fast path (defer stats/accounting to backend) // // Comparison with current design: // - Current: 20+ instructions (Magazine → SuperSlab → ACE → ...) // - New: 3-4 instructions (TLS freelist pop only) // - Reduction: -80% instructions in hot path // // Inspired by: // - System tcache (glibc malloc) - 3-4 instruction fast path // - HAKX Mid-Large (+171%) - "Simple Front + Smart Back" // - Box Theory - Clear boundaries, minimal coupling