bb70d422dc
Summary: - Implemented free path supply with ENV-gated A/B modes (HAKMEM_TINY_HEAP_V2_LEFTOVER_MODE) - Mode 0 (Stealing, default): L0 gets freed blocks first → +18% @ 32B - Mode 1 (Leftover): L1 primary owner, L0 gets leftovers → Box-clean but -5% @ 16B - Decision: Default to Stealing for performance (ChatGPT analysis: L0 doesn't corrupt learning layer signals) Performance (100K iterations, workset=128): - 16B: 43.9M → 45.6M ops/s (+3.9%) - 32B: 41.9M → 49.6M ops/s (+18.4%) ✅ - 64B: 51.2M → 51.5M ops/s (+0.6%) - 100% magazine hit rate (supply from free path working correctly) Implementation: - tiny_free_fast_v2.inc.h: Dual-mode supply (lines 134-166) - tiny_heap_v2.h: Add tiny_heap_v2_leftover_mode() flag + rationale doc - tiny_alloc_fast.inc.h: Alloc hook with tiny_heap_v2_alloc_by_class() - CURRENT_TASK.md: Updated Phase 13-B status (complete) with A/B results ENV flags: - HAKMEM_TINY_HEAP_V2=1 # Enable TinyHeapV2 - HAKMEM_TINY_HEAP_V2_LEFTOVER_MODE=0 # Mode 0 (Stealing, default) - HAKMEM_TINY_HEAP_V2_CLASS_MASK=0xE # C1-C3 only (skip C0 -5% regression) - HAKMEM_TINY_HEAP_V2_STATS=1 # Print statistics 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
792 lines
30 KiB
C
792 lines
30 KiB
C
// tiny_alloc_fast.inc.h - Box 5: Allocation Fast Path (3-4 instructions)
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// Purpose: Ultra-fast TLS freelist pop (inspired by System tcache & Mid-Large HAKX +171%)
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// Invariant: Hit rate > 95% → 3-4 instructions, Miss → refill from backend
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// Design: "Simple Front + Smart Back" - Front is dumb & fast, Back is smart
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//
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// Box 5-NEW: SFC (Super Front Cache) Integration
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// Architecture: SFC (Layer 0, 128-256 slots) → SLL (Layer 1, unlimited) → SuperSlab (Layer 2+)
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// Cascade Refill: SFC ← SLL (one-way, safe)
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// Goal: +200% performance (4.19M → 12M+ ops/s)
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//
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// Phase 2b: Adaptive TLS Cache Sizing
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// Hot classes grow to 2048 slots, cold classes shrink to 16 slots
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// Expected: +3-10% performance, -30-50% TLS cache memory overhead
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#pragma once
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#include "tiny_atomic.h"
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#include "hakmem_tiny.h"
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#include "tiny_route.h"
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#include "tiny_alloc_fast_sfc.inc.h" // Box 5-NEW: SFC Layer
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#include "hakmem_tiny_fastcache.inc.h" // Array stack (FastCache) for C0–C3
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#include "hakmem_tiny_tls_list.h" // TLS List (for tiny_fast_refill_and_take)
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#include "tiny_region_id.h" // Phase 7: Header-based class_idx lookup
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#include "tiny_adaptive_sizing.h" // Phase 2b: Adaptive sizing
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#include "box/tls_sll_box.h" // Box TLS-SLL: C7-safe push/pop/splice
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#include "box/tiny_next_ptr_box.h" // Box API: Next pointer read/write
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#ifdef HAKMEM_TINY_FRONT_GATE_BOX
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#include "box/front_gate_box.h"
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#endif
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#include "hakmem_tiny_integrity.h" // PRIORITY 1-4: Corruption detection
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#ifdef HAKMEM_TINY_HEADER_CLASSIDX
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#include "front/tiny_front_c23.h" // Phase B: Ultra-simple C2/C3 front
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#include "front/tiny_heap_v2.h" // Phase 13-A: TinyHeapV2 magazine front
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#endif
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#include <stdio.h>
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// Phase 7 Task 2: Aggressive inline TLS cache access
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// Enable with: make HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1
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#ifndef HAKMEM_TINY_AGGRESSIVE_INLINE
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#define HAKMEM_TINY_AGGRESSIVE_INLINE 0
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#endif
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#if HAKMEM_TINY_AGGRESSIVE_INLINE
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#include "tiny_alloc_fast_inline.h"
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#endif
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// ========== Debug Counters (compile-time gated) ==========
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#if HAKMEM_DEBUG_COUNTERS
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// Refill-stage counters (defined in hakmem_tiny.c)
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extern unsigned long long g_rf_total_calls[];
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extern unsigned long long g_rf_hit_bench[];
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extern unsigned long long g_rf_hit_hot[];
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extern unsigned long long g_rf_hit_mail[];
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extern unsigned long long g_rf_hit_slab[];
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extern unsigned long long g_rf_hit_ss[];
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extern unsigned long long g_rf_hit_reg[];
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extern unsigned long long g_rf_mmap_calls[];
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// Publish hits (defined in hakmem_tiny.c)
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extern unsigned long long g_pub_mail_hits[];
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extern unsigned long long g_pub_bench_hits[];
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extern unsigned long long g_pub_hot_hits[];
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// Free pipeline (defined in hakmem_tiny.c)
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extern unsigned long long g_free_via_tls_sll[];
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#endif
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// ========== Box 5: Allocation Fast Path ==========
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// 箱理論の Fast Allocation 層。TLS freelist から直接 pop（3-4命令）。
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// 不変条件:
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// - TLS freelist が非空なら即座に return (no lock, no sync)
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// - Miss なら Backend (Box 3: SuperSlab) に委譲
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// - Cross-thread allocation は考慮しない（Backend が処理）
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// External TLS variables (defined in hakmem_tiny.c)
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extern __thread void* g_tls_sll_head[TINY_NUM_CLASSES];
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extern __thread uint32_t g_tls_sll_count[TINY_NUM_CLASSES];
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// External backend functions
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// P0 Fix: Use appropriate refill function based on P0 status
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#if HAKMEM_TINY_P0_BATCH_REFILL
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extern int sll_refill_batch_from_ss(int class_idx, int max_take);
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#else
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extern int sll_refill_small_from_ss(int class_idx, int max_take);
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#endif
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// NEW: Direct SS→FC refill (bypasses SLL)
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extern int ss_refill_fc_fill(int class_idx, int want);
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extern void* hak_tiny_alloc_slow(size_t size, int class_idx);
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extern int hak_tiny_size_to_class(size_t size);
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extern int tiny_refill_failfast_level(void);
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extern const size_t g_tiny_class_sizes[];
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// Hot-class toggle: class5 (256B) dedicated TLS fast path
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extern int g_tiny_hotpath_class5;
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// Minimal class5 refill helper: fixed, branch-light refill into TLS List, then take one
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// Preconditions: class_idx==5 and g_tiny_hotpath_class5==1
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static inline void* tiny_class5_minirefill_take(void) {
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extern __thread TinyTLSList g_tls_lists[TINY_NUM_CLASSES];
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TinyTLSList* tls5 = &g_tls_lists[5];
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// Fast pop if available
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void* base = tls_list_pop(tls5, 5);
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if (base) {
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// ✅ FIX #16: Return BASE pointer (not USER)
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// Caller will apply HAK_RET_ALLOC which does BASE → USER conversion
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return base;
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}
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// Robust refill via generic helper（header対応・境界検証済み）
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return tiny_fast_refill_and_take(5, tls5);
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}
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// Global Front refill config (parsed at init; defined in hakmem_tiny.c)
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extern int g_refill_count_global;
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extern int g_refill_count_hot;
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extern int g_refill_count_mid;
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extern int g_refill_count_class[TINY_NUM_CLASSES];
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// HAK_RET_ALLOC macro is now defined in core/hakmem_tiny.c
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// See lines 116-152 for single definition point based on HAKMEM_TINY_HEADER_CLASSIDX
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// ========== RDTSC Profiling (lightweight) ==========
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#ifdef __x86_64__
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static inline uint64_t tiny_fast_rdtsc(void) {
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unsigned int lo, hi;
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__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
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return ((uint64_t)hi << 32) | lo;
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}
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#else
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static inline uint64_t tiny_fast_rdtsc(void) { return 0; }
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#endif
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// Per-thread profiling counters (enable with HAKMEM_TINY_PROFILE=1)
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static __thread uint64_t g_tiny_alloc_hits = 0;
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static __thread uint64_t g_tiny_alloc_cycles = 0;
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static __thread uint64_t g_tiny_refill_calls = 0;
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static __thread uint64_t g_tiny_refill_cycles = 0;
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static int g_tiny_profile_enabled = -1; // -1: uninitialized
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static inline int tiny_profile_enabled(void) {
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if (__builtin_expect(g_tiny_profile_enabled == -1, 0)) {
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const char* env = getenv("HAKMEM_TINY_PROFILE");
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g_tiny_profile_enabled = (env && *env && *env != '0') ? 1 : 0;
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}
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return g_tiny_profile_enabled;
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}
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// Print profiling results at exit
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static void tiny_fast_print_profile(void) __attribute__((destructor));
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static void tiny_fast_print_profile(void) {
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if (!tiny_profile_enabled()) return;
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if (g_tiny_alloc_hits == 0 && g_tiny_refill_calls == 0) return;
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fprintf(stderr, "\n========== Box Theory Fast Path Profile ==========\n");
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if (g_tiny_alloc_hits > 0) {
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fprintf(stderr, "[ALLOC HIT] count=%lu, avg_cycles=%lu\n",
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(unsigned long)g_tiny_alloc_hits,
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(unsigned long)(g_tiny_alloc_cycles / g_tiny_alloc_hits));
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}
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if (g_tiny_refill_calls > 0) {
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fprintf(stderr, "[REFILL] count=%lu, avg_cycles=%lu\n",
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(unsigned long)g_tiny_refill_calls,
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(unsigned long)(g_tiny_refill_cycles / g_tiny_refill_calls));
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}
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fprintf(stderr, "===================================================\n\n");
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}
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// ========== Fast Path: TLS Freelist Pop (3-4 instructions) ==========
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// External SFC control (defined in hakmem_tiny_sfc.c)
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extern int g_sfc_enabled;
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// Allocation fast path (inline for zero-cost)
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// Returns: pointer on success, NULL on miss (caller should try refill/slow)
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//
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// Box 5-NEW Architecture:
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// Layer 0: SFC (128-256 slots, high hit rate) [if enabled]
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// Layer 1: SLL (unlimited, existing)
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// Cascade: SFC miss → try SLL → refill
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//
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// Assembly (x86-64, optimized):
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// mov rax, QWORD PTR g_sfc_head[class_idx] ; SFC: Load head
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// test rax, rax ; Check NULL
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// jne .sfc_hit ; If not empty, SFC hit!
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// mov rax, QWORD PTR g_tls_sll_head[class_idx] ; SLL: Load head
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// test rax, rax ; Check NULL
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// je .miss ; If empty, miss
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// mov rdx, QWORD PTR [rax] ; Load next
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// mov QWORD PTR g_tls_sll_head[class_idx], rdx ; Update head
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// ret ; Return ptr
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// .sfc_hit:
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// mov rdx, QWORD PTR [rax] ; Load next
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// mov QWORD PTR g_sfc_head[class_idx], rdx ; Update head
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// ret
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// .miss:
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// ; Fall through to refill
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//
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// Expected: 3-4 instructions on SFC hit, 6-8 on SLL hit
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static inline void* tiny_alloc_fast_pop(int class_idx) {
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// PRIORITY 1: Bounds check before any TLS array access
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HAK_CHECK_CLASS_IDX(class_idx, "tiny_alloc_fast_pop");
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#if !HAKMEM_BUILD_RELEASE
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// Phase 3: Debug counters eliminated in release builds
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atomic_fetch_add(&g_integrity_check_class_bounds, 1);
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// DEBUG: Log class 2 pops (DISABLED for performance)
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static _Atomic uint64_t g_fast_pop_count = 0;
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uint64_t pop_call = atomic_fetch_add(&g_fast_pop_count, 1);
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if (0 && class_idx == 2 && pop_call > 5840 && pop_call < 5900) {
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fprintf(stderr, "[FAST_POP_C2] call=%lu cls=%d head=%p count=%u\n",
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pop_call, class_idx, g_tls_sll_head[class_idx], g_tls_sll_count[class_idx]);
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fflush(stderr);
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}
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#endif
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// Phase E1-CORRECT: C7 now has headers, can use fast path
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#ifdef HAKMEM_TINY_FRONT_GATE_BOX
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void* out = NULL;
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if (front_gate_try_pop(class_idx, &out)) {
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return out;
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}
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return NULL;
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#else
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// Phase 7 Task 3: Profiling overhead removed in release builds
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// In release mode, compiler can completely eliminate profiling code
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#if !HAKMEM_BUILD_RELEASE
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uint64_t start = tiny_profile_enabled() ? tiny_fast_rdtsc() : 0;
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#endif
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// Phase 1: Try array stack (FastCache) first for hottest tiny classes (C0–C3)
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if (__builtin_expect(g_fastcache_enable && class_idx <= 3, 1)) {
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void* fc = fastcache_pop(class_idx);
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if (__builtin_expect(fc != NULL, 1)) {
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// Frontend FastCache hit
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extern unsigned long long g_front_fc_hit[];
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g_front_fc_hit[class_idx]++;
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return fc;
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} else {
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extern unsigned long long g_front_fc_miss[];
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g_front_fc_miss[class_idx]++;
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}
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}
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// Box 5-NEW: Layer 0 - Try SFC first (if enabled)
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// Cache g_sfc_enabled in TLS to avoid global load on every allocation
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static __thread int sfc_check_done = 0;
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static __thread int sfc_is_enabled = 0;
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if (__builtin_expect(!sfc_check_done, 0)) {
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sfc_is_enabled = g_sfc_enabled;
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sfc_check_done = 1;
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}
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if (__builtin_expect(sfc_is_enabled, 1)) {
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void* base = sfc_alloc(class_idx);
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if (__builtin_expect(base != NULL, 1)) {
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// Front Gate: SFC hit
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extern unsigned long long g_front_sfc_hit[];
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g_front_sfc_hit[class_idx]++;
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// 🚀 SFC HIT! (Layer 0)
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#if !HAKMEM_BUILD_RELEASE
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if (start) {
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g_tiny_alloc_cycles += (tiny_fast_rdtsc() - start);
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g_tiny_alloc_hits++;
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}
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#endif
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// ✅ FIX #16: Return BASE pointer (not USER)
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// Caller (tiny_alloc_fast) will call HAK_RET_ALLOC → tiny_region_id_write_header
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// which does the BASE → USER conversion. Double conversion was causing corruption!
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return base;
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}
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// SFC miss → try SLL (Layer 1)
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}
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// Box Boundary: Layer 1 - TLS SLL freelist の先頭を pop（envで無効化可）
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extern int g_tls_sll_enable; // set at init via HAKMEM_TINY_TLS_SLL
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if (__builtin_expect(g_tls_sll_enable, 1)) {
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// Use Box TLS-SLL API (C7-safe pop)
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// CRITICAL: Pop FIRST, do NOT read g_tls_sll_head directly (race condition!)
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// Reading head before pop causes stale read → rbp=0xa0 SEGV
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void* base = NULL;
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if (tls_sll_pop(class_idx, &base)) {
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// Front Gate: SLL hit (fast path 3 instructions)
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extern unsigned long long g_front_sll_hit[];
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g_front_sll_hit[class_idx]++;
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#if HAKMEM_DEBUG_COUNTERS
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// Track TLS freelist hits (compile-time gated, zero runtime cost when disabled)
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g_free_via_tls_sll[class_idx]++;
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#endif
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#if !HAKMEM_BUILD_RELEASE
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// Debug: Track profiling (release builds skip this overhead)
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if (start) {
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g_tiny_alloc_cycles += (tiny_fast_rdtsc() - start);
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g_tiny_alloc_hits++;
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}
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#endif
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// ✅ FIX #16: Return BASE pointer (not USER)
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// Caller (tiny_alloc_fast) will call HAK_RET_ALLOC → tiny_region_id_write_header
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// which does the BASE → USER conversion. Double conversion was causing corruption!
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return base;
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}
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}
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// Fast path miss → NULL (caller should refill)
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return NULL;
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#endif
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}
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// ========== Cascade Refill: SFC ← SLL (Box Theory boundary) ==========
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// Cascade refill: Transfer blocks from SLL to SFC (one-way, safe)
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// Returns: number of blocks transferred
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//
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// Contract:
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// - Transfer ownership: SLL → SFC
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// - No circular dependency: one-way only
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// - Boundary clear: SLL pop → SFC push
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// - Fallback safe: if SFC full, stop (no overflow)
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// Env-driven cascade percentage (0-100), default 50%
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static inline int sfc_cascade_pct(void) {
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static int pct = -1;
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if (__builtin_expect(pct == -1, 0)) {
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const char* e = getenv("HAKMEM_SFC_CASCADE_PCT");
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int v = e && *e ? atoi(e) : 50;
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if (v < 0) v = 0; if (v > 100) v = 100;
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pct = v;
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}
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return pct;
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}
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static inline int sfc_refill_from_sll(int class_idx, int target_count) {
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// PRIORITY 1: Bounds check
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HAK_CHECK_CLASS_IDX(class_idx, "sfc_refill_from_sll");
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atomic_fetch_add(&g_integrity_check_class_bounds, 1);
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int transferred = 0;
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uint32_t cap = g_sfc_capacity[class_idx];
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// Adjust target based on cascade percentage
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int pct = sfc_cascade_pct();
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int want = (target_count * pct) / 100;
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if (want <= 0) want = target_count / 2; // safety fallback
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while (transferred < want && g_tls_sll_count[class_idx] > 0) {
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// Check SFC capacity before transfer
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if (g_sfc_count[class_idx] >= cap) {
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break; // SFC full, stop
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}
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// Pop from SLL (Layer 1) using Box TLS-SLL API (C7-safe)
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void* ptr = NULL;
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if (!tls_sll_pop(class_idx, &ptr)) {
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break; // SLL empty
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}
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// Push to SFC (Layer 0) — header-aware
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tiny_next_write(class_idx, ptr, g_sfc_head[class_idx]);
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g_sfc_head[class_idx] = ptr;
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g_sfc_count[class_idx]++;
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transferred++;
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}
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return transferred;
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}
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// ========== Refill Path: Backend Integration ==========
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// Refill TLS freelist from backend (SuperSlab/ACE/Learning layer)
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// Returns: number of blocks refilled
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//
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// Box 5-NEW Architecture:
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// SFC enabled: SuperSlab → SLL → SFC (cascade)
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// SFC disabled: SuperSlab → SLL (direct, old path)
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//
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// This integrates with existing HAKMEM infrastructure:
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// - SuperSlab provides memory chunks
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// - ACE provides adaptive capacity learning
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// - L25 provides mid-large integration
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//
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// Refill count is tunable via HAKMEM_TINY_REFILL_COUNT (default: 16)
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// - Smaller count (8-16): better for diverse workloads, faster warmup
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// - Larger count (64-128): better for homogeneous workloads, fewer refills
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static inline int tiny_alloc_fast_refill(int class_idx) {
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// Phase E1-CORRECT: C7 now has headers, can use refill
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// Phase 7 Task 3: Profiling overhead removed in release builds
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// In release mode, compiler can completely eliminate profiling code
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#if !HAKMEM_BUILD_RELEASE
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uint64_t start = tiny_profile_enabled() ? tiny_fast_rdtsc() : 0;
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#endif
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// Phase 2b: Check available capacity before refill
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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)
|
||
// Refill Dispatch: Standard (ss_refill_fc_fill) vs Legacy SLL (A/B only)
|
||
// Standard: Enabled by FRONT_DIRECT=1, REFILL_BATCH=1, or P0_DIRECT_FC_ALL=1
|
||
// Legacy: Fallback for compatibility (will be deprecated)
|
||
int refilled = 0;
|
||
|
||
// NEW: Front-Direct refill control (A/B toggle)
|
||
static __thread int s_use_front_direct = -1;
|
||
if (__builtin_expect(s_use_front_direct == -1, 0)) {
|
||
// Check multiple ENV flags (any one enables Front-Direct)
|
||
const char* e1 = getenv("HAKMEM_TINY_FRONT_DIRECT");
|
||
const char* e2 = getenv("HAKMEM_TINY_P0_DIRECT_FC_ALL");
|
||
const char* e3 = getenv("HAKMEM_TINY_REFILL_BATCH");
|
||
s_use_front_direct = ((e1 && *e1 && *e1 != '0') ||
|
||
(e2 && *e2 && *e2 != '0') ||
|
||
(e3 && *e3 && *e3 != '0')) ? 1 : 0;
|
||
}
|
||
|
||
// Refill dispatch
|
||
if (s_use_front_direct) {
|
||
// NEW: Direct SS→FC (bypasses SLL)
|
||
refilled = ss_refill_fc_fill(class_idx, cnt);
|
||
} else {
|
||
// Legacy: SS→SLL→FC (via batch or generic)
|
||
#if HAKMEM_TINY_P0_BATCH_REFILL
|
||
refilled = sll_refill_batch_from_ss(class_idx, cnt);
|
||
#else
|
||
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 (opt-in via HAKMEM_TINY_SFC_CASCADE, off by default)
|
||
// NEW: Default OFF, enable via HAKMEM_TINY_SFC_CASCADE=1
|
||
// Skip entirely when Front-Direct is active (direct SS→FC path)
|
||
static __thread int sfc_cascade_enabled = -1;
|
||
if (__builtin_expect(sfc_cascade_enabled == -1, 0)) {
|
||
// Front-Direct bypasses SLL, so SFC cascade is pointless
|
||
if (s_use_front_direct) {
|
||
sfc_cascade_enabled = 0;
|
||
} else {
|
||
// Check ENV flag (default: OFF)
|
||
const char* e = getenv("HAKMEM_TINY_SFC_CASCADE");
|
||
sfc_cascade_enabled = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
}
|
||
|
||
// Only cascade if explicitly enabled AND we have refilled blocks in SLL
|
||
if (sfc_cascade_enabled && g_sfc_enabled && refilled > 0) {
|
||
// Skip SFC cascade for class5 when dedicated hotpath is enabled
|
||
if (g_tiny_hotpath_class5 && class_idx == 5) {
|
||
// no-op: keep refilled blocks in TLS List/SLL
|
||
} else {
|
||
// 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) {
|
||
#if !HAKMEM_BUILD_RELEASE
|
||
// Phase 3: Debug counters eliminated in release builds
|
||
static _Atomic uint64_t alloc_call_count = 0;
|
||
uint64_t call_num = atomic_fetch_add(&alloc_call_count, 1);
|
||
#endif
|
||
|
||
// 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
|
||
}
|
||
|
||
#if !HAKMEM_BUILD_RELEASE
|
||
// Phase 3: Debug checks eliminated in release builds
|
||
// CRITICAL: Bounds check to catch corruption
|
||
if (__builtin_expect(class_idx >= TINY_NUM_CLASSES, 0)) {
|
||
fprintf(stderr, "[TINY_ALLOC_FAST] FATAL: class_idx=%d out of bounds! size=%zu call=%lu\n",
|
||
class_idx, size, call_num);
|
||
fflush(stderr);
|
||
abort();
|
||
}
|
||
|
||
// Debug logging (DISABLED for performance)
|
||
if (0 && call_num > 14250 && call_num < 14280) {
|
||
fprintf(stderr, "[TINY_ALLOC] call=%lu size=%zu class=%d sll_head[%d]=%p count=%u\n",
|
||
call_num, size, class_idx, class_idx,
|
||
g_tls_sll_head[class_idx], g_tls_sll_count[class_idx]);
|
||
fflush(stderr);
|
||
}
|
||
#endif
|
||
|
||
ROUTE_BEGIN(class_idx);
|
||
|
||
void* ptr = NULL;
|
||
const int hot_c5 = (g_tiny_hotpath_class5 && class_idx == 5);
|
||
|
||
// Phase B: Ultra-simple front for C2/C3 (128B/256B)
|
||
// ENV-gated: HAKMEM_TINY_FRONT_C23_SIMPLE=1
|
||
// Target: 15-20M ops/s (vs current 8-9M ops/s)
|
||
#ifdef HAKMEM_TINY_HEADER_CLASSIDX
|
||
if (tiny_front_c23_enabled() && (class_idx == 2 || class_idx == 3)) {
|
||
void* c23_ptr = tiny_front_c23_alloc(size, class_idx);
|
||
if (c23_ptr) {
|
||
HAK_RET_ALLOC(class_idx, c23_ptr);
|
||
}
|
||
// Fall through to existing path if C23 path failed (NULL)
|
||
}
|
||
#endif
|
||
|
||
// Phase 13-A: TinyHeapV2 (per-thread magazine, experimental)
|
||
// ENV-gated: HAKMEM_TINY_HEAP_V2=1
|
||
// Targets class 0-3 (8-64B) only, falls back to existing path if NULL
|
||
// PERF: Pass class_idx directly to avoid redundant size→class conversion
|
||
if (__builtin_expect(tiny_heap_v2_enabled(), 0) && class_idx <= 3) {
|
||
void* base = tiny_heap_v2_alloc_by_class(class_idx);
|
||
if (base) {
|
||
HAK_RET_ALLOC(class_idx, base); // Header write + return USER pointer
|
||
}
|
||
}
|
||
|
||
// NEW: Front-Direct/SLL-OFF bypass control (TLS cached, lazy init)
|
||
static __thread int s_front_direct_alloc = -1;
|
||
if (__builtin_expect(s_front_direct_alloc == -1, 0)) {
|
||
const char* e = getenv("HAKMEM_TINY_FRONT_DIRECT");
|
||
s_front_direct_alloc = (e && *e && *e != '0') ? 1 : 0;
|
||
}
|
||
|
||
if (__builtin_expect(hot_c5, 0)) {
|
||
// class5: 専用最短経路（generic frontは一切通らない）
|
||
void* p = tiny_class5_minirefill_take();
|
||
if (p) HAK_RET_ALLOC(class_idx, p);
|
||
|
||
int refilled = tiny_alloc_fast_refill(class_idx);
|
||
if (__builtin_expect(refilled > 0, 1)) {
|
||
p = tiny_class5_minirefill_take();
|
||
if (p) HAK_RET_ALLOC(class_idx, p);
|
||
}
|
||
|
||
// slow pathへ（genericフロントは回避）
|
||
ptr = hak_tiny_alloc_slow(size, class_idx);
|
||
if (ptr) HAK_RET_ALLOC(class_idx, ptr);
|
||
return ptr; // NULL if OOM
|
||
}
|
||
|
||
// Generic front (FastCache/SFC/SLL)
|
||
// Respect SLL global toggle AND Front-Direct mode; when either disabled, skip TLS SLL entirely
|
||
if (__builtin_expect(g_tls_sll_enable && !s_front_direct_alloc, 1)) {
|
||
// For classes 0..3 keep ultra-inline POP; for >=4 use safe Box POP to avoid UB on bad heads.
|
||
if (class_idx <= 3) {
|
||
#if HAKMEM_TINY_INLINE_SLL
|
||
// Experimental: Inline SLL pop (A/B only, requires HAKMEM_TINY_INLINE_SLL=1)
|
||
TINY_ALLOC_FAST_POP_INLINE(class_idx, ptr);
|
||
#else
|
||
// Default: Safe Box API (Box TLS-SLL) for all standard builds
|
||
ptr = tiny_alloc_fast_pop(class_idx);
|
||
#endif
|
||
} else {
|
||
void* base = NULL;
|
||
if (tls_sll_pop(class_idx, &base)) ptr = base; else ptr = NULL;
|
||
}
|
||
} else {
|
||
ptr = NULL; // SLL disabled OR Front-Direct active → bypass SLL
|
||
}
|
||
|
||
if (__builtin_expect(ptr != NULL, 1)) {
|
||
HAK_RET_ALLOC(class_idx, ptr);
|
||
}
|
||
|
||
// Generic: Refill and take (Front-Direct vs Legacy)
|
||
if (s_front_direct_alloc) {
|
||
// Front-Direct: Direct SS→FC refill (bypasses SLL/TLS List)
|
||
int refilled_fc = tiny_alloc_fast_refill(class_idx);
|
||
if (__builtin_expect(refilled_fc > 0, 1)) {
|
||
void* fc_ptr = fastcache_pop(class_idx);
|
||
if (fc_ptr) {
|
||
HAK_RET_ALLOC(class_idx, fc_ptr);
|
||
}
|
||
}
|
||
} else {
|
||
// Legacy: Refill to TLS List/SLL
|
||
extern __thread TinyTLSList g_tls_lists[TINY_NUM_CLASSES];
|
||
void* took = tiny_fast_refill_and_take(class_idx, &g_tls_lists[class_idx]);
|
||
if (took) {
|
||
HAK_RET_ALLOC(class_idx, took);
|
||
}
|
||
}
|
||
|
||
// Backend refill後に再トライ
|
||
{
|
||
int refilled = tiny_alloc_fast_refill(class_idx);
|
||
if (__builtin_expect(refilled > 0, 1)) {
|
||
// Skip SLL retry if Front-Direct OR SLL disabled
|
||
if (__builtin_expect(g_tls_sll_enable && !s_front_direct_alloc, 1)) {
|
||
if (class_idx <= 3) {
|
||
#if HAKMEM_TINY_INLINE_SLL
|
||
// Experimental: Inline SLL pop (A/B only, requires HAKMEM_TINY_INLINE_SLL=1)
|
||
TINY_ALLOC_FAST_POP_INLINE(class_idx, ptr);
|
||
#else
|
||
// Default: Safe Box API (Box TLS-SLL) for all standard builds
|
||
ptr = tiny_alloc_fast_pop(class_idx);
|
||
#endif
|
||
} else {
|
||
void* base2 = NULL;
|
||
if (tls_sll_pop(class_idx, &base2)) ptr = base2; else ptr = NULL;
|
||
}
|
||
} else {
|
||
ptr = NULL; // SLL disabled OR Front-Direct active → bypass SLL
|
||
}
|
||
if (ptr) {
|
||
HAK_RET_ALLOC(class_idx, ptr);
|
||
}
|
||
}
|
||
}
|
||
|
||
// 5. 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 using Box TLS-SLL API (C7-safe)
|
||
uint32_t capacity = UINT32_MAX; // Unlimited for helper function
|
||
if (!tls_sll_push(class_idx, ptr, capacity)) {
|
||
// C7 rejected or SLL somehow full (should not happen)
|
||
// In release builds, this is a no-op (caller expects success)
|
||
#if !HAKMEM_BUILD_RELEASE
|
||
fprintf(stderr, "[WARN] tls_sll_push failed in tiny_alloc_fast_push cls=%d ptr=%p\n",
|
||
class_idx, ptr);
|
||
#endif
|
||
}
|
||
#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
|