0bc33dc4f5
Phase 9-2: Remove Legacy Backend & Unify to Shared Pool (50M ops/s)
...
- Removed Legacy Backend fallback; Shared Pool is now the sole backend.
- Removed Soft Cap limit in Shared Pool to allow full memory management.
- Implemented EMPTY slab recycling with batched meta->used decrement in remote drain.
- Updated tiny_free_local_box to return is_empty status for safe recycling.
- Fixed race condition in release path by removing from legacy list early.
- Achieved 50.3M ops/s in WS8192 benchmark (+200% vs baseline).
2025-12-01 13:47:23 +09:00
cfa5e4e91c
ENV Cleanup Step 7: Gate debug ENV vars in core/box/free_local_box.c
...
Changes:
- Gated HAKMEM_TINY_SLL_DIAG (2 call sites) behind #if !HAKMEM_BUILD_RELEASE
- Gated HAKMEM_TINY_FREELIST_MASK behind #if !HAKMEM_BUILD_RELEASE
- Gated HAKMEM_SS_FREE_DEBUG behind #if !HAKMEM_BUILD_RELEASE
- Entire diagnostic blocks wrapped (not just getenv) to avoid compilation errors
- ENV variables gated: HAKMEM_TINY_SLL_DIAG, HAKMEM_TINY_FREELIST_MASK, HAKMEM_SS_FREE_DEBUG
Performance: 30.4M ops/s Larson (baseline 30.4M, perfect match)
Build: Clean, pre-existing warnings only
FIX: Previous version had scoping issue with static variables inside do{}while blocks
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-28 01:10:26 +09:00
25d963a4aa
Code Cleanup: Remove false positives, redundant validations, and reduce verbose logging
...
Following the C7 stride upgrade fix (commit 23c0d9541✅ Successful (LTO warnings expected)
- Test: ✅ 10K iterations (1.87M ops/s, no crashes)
- NXT_MISALIGN false positives: ✅ Eliminated
## Files Modified
- core/tiny_nextptr.h - Disabled false positive NXT_MISALIGN check
- core/hakmem_tiny_refill_p0.inc.h - Removed redundant CARVE validation
- core/box/ss_legacy_backend_box.c - Removed redundant LEGACY validation
- core/hakmem_shared_pool.c - Made SP_FIX_GEOMETRY logging debug-only
## Impact
- **Code clarity**: Removed 43 lines of redundant validation code
- **Debug noise**: Reduced false positive diagnostics
- **Performance**: Eliminated overhead from redundant geometry checks
- **Maintainability**: Single source of truth for geometry validation
🧹 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-21 23:00:24 +09:00
6afaa5703a
Phase 12-1.1: EMPTY Slab Detection + Immediate Reuse (+13% improvement, 10.2M→11.5M ops/s)
...
Implementation of Task-sensei Priority 1 recommendation: Add empty_mask to SuperSlab
for immediate EMPTY slab detection and reuse, reducing Stage 3 (mmap) overhead.
## Changes
### 1. SuperSlab Structure (core/superslab/superslab_types.h)
- Added `empty_mask` (uint32_t): Bitmap for EMPTY slabs (used==0)
- Added `empty_count` (uint8_t): Quick check for EMPTY slab availability
### 2. EMPTY Detection API (core/box/ss_hot_cold_box.h)
- Added `ss_is_slab_empty()`: Returns true if slab is completely EMPTY
- Added `ss_mark_slab_empty()`: Marks slab as EMPTY (highest reuse priority)
- Added `ss_clear_slab_empty()`: Removes EMPTY state when reactivated
- Updated `ss_update_hot_cold_indices()`: Classify EMPTY/Hot/Cold slabs
- Updated `ss_init_hot_cold()`: Initialize empty_mask/empty_count
### 3. Free Path Integration (core/box/free_local_box.c)
- After `meta->used--`, check if `meta->used == 0`
- If true, call `ss_mark_slab_empty()` to update empty_mask
- Enables immediate EMPTY detection on every free operation
### 4. Shared Pool Stage 0.5 (core/hakmem_shared_pool.c)
- New Stage 0.5 before Stage 1: Scan existing SuperSlabs for EMPTY slabs
- Iterate over `g_super_reg_by_class[class_idx][]` (first 16 entries)
- Check `ss->empty_count > 0` → scan `empty_mask` with `__builtin_ctz()`
- Reuse EMPTY slab directly, avoiding Stage 3 (mmap/lock overhead)
- ENV control: `HAKMEM_SS_EMPTY_REUSE=1` (default OFF for A/B testing)
- ENV tunable: `HAKMEM_SS_EMPTY_SCAN_LIMIT=N` (default 16 SuperSlabs)
## Performance Results
```
Benchmark: Random Mixed 256B (100K iterations)
OFF (default): 10.2M ops/s (baseline)
ON (ENV=1): 11.5M ops/s (+13.0% improvement) ✅
```
## Expected Impact (from Task-sensei analysis)
**Current bottleneck**:
- Stage 1: 2-5% hit rate (free list broken)
- Stage 2: 3-8% hit rate (rare UNUSED)
- Stage 3: 87-95% hit rate (lock + mmap overhead) ← bottleneck
**Expected with Phase 12-1.1**:
- Stage 0.5: 20-40% hit rate (EMPTY scan)
- Stage 1-2: 20-30% hit rate (combined)
- Stage 3: 30-50% hit rate (significantly reduced)
**Theoretical max**: 25M → 55-70M ops/s (+120-180%)
## Current Gap Analysis
**Observed**: 11.5M ops/s (+13%)
**Expected**: 55-70M ops/s (+120-180%)
**Gap**: Performance regression or missing complementary optimizations
Possible causes:
1. Phase 3d-C (25.1M→10.2M) regression - unrelated to this change
2. EMPTY scan overhead (16 SuperSlabs × empty_count check)
3. Missing Priority 2-5 optimizations (Lazy SS deallocation, etc.)
4. Stage 0.5 too conservative (scan_limit=16, should be higher?)
## Usage
```bash
# Enable EMPTY reuse optimization
export HAKMEM_SS_EMPTY_REUSE=1
# Optional: increase scan limit (trade-off: throughput vs latency)
export HAKMEM_SS_EMPTY_SCAN_LIMIT=32
./bench_random_mixed_hakmem 100000 256 42
```
## Next Steps
**Priority 1-A**: Investigate Phase 3d-C→12-1.1 regression (25.1M→10.2M)
**Priority 1-B**: Implement Phase 12-1.2 (Lazy SS deallocation) for complementary effect
**Priority 1-C**: Profile Stage 0.5 overhead (scan_limit tuning)
## Files Modified
Core implementation:
- `core/superslab/superslab_types.h` - empty_mask/empty_count fields
- `core/box/ss_hot_cold_box.h` - EMPTY detection/marking API
- `core/box/free_local_box.c` - Free path EMPTY detection
- `core/hakmem_shared_pool.c` - Stage 0.5 EMPTY scan
Documentation:
- `CURRENT_TASK.md` - Task-sensei investigation report
---
🎯 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
Co-Authored-By: Task-sensei (investigation & design analysis)
2025-11-21 04:56:48 +09:00
f95448c767
CRITICAL DISCOVERY: Phase 9 LRU architecturally unreachable due to TLS SLL
...
Root Cause:
- TLS SLL fast path (95-99% of frees) does NOT decrement meta->used
- Slabs never appear empty (meta->used never reaches 0)
- superslab_free() never called
- hak_ss_lru_push() never called
- LRU cache utilization: 0% (should be >90%)
Impact:
- mmap/munmap churn: 6,455 syscalls (74.8% time)
- Performance: -94% regression (9.38M → 563K ops/s)
- Phase 9 design goal: FAILED (lazy deallocation non-functional)
Evidence:
- 200K iterations: [LRU_PUSH]=0, [LRU_POP]=877 misses
- Experimental verification with debug logs confirms theory
Solution: Option B - Periodic TLS SLL Drain
- Every 1,024 frees: drain TLS SLL → slab freelist
- Decrement meta->used properly → enable empty detection
- Expected: -96% syscalls, +1,300-1,700% throughput
Files:
- PHASE9_LRU_ARCHITECTURE_ISSUE.md: Comprehensive analysis (300+ lines)
- Includes design options A/B/C/D with tradeoff analysis
Next: Await ultrathink approval to implement Option B
2025-11-14 06:49:32 +09:00
03df05ec75
Phase 12: Shared SuperSlab Pool implementation (WIP - runtime crash)
...
## Summary
Implemented Phase 12 Shared SuperSlab Pool (mimalloc-style) to address
SuperSlab allocation churn (877 SuperSlabs → 100-200 target).
## Implementation (ChatGPT + Claude)
1. **Metadata changes** (superslab_types.h):
- Added class_idx to TinySlabMeta (per-slab dynamic class)
- Removed size_class from SuperSlab (no longer per-SuperSlab)
- Changed owner_tid (16-bit) → owner_tid_low (8-bit)
2. **Shared Pool** (hakmem_shared_pool.{h,c}):
- Global pool shared by all size classes
- shared_pool_acquire_slab() - Get free slab for class_idx
- shared_pool_release_slab() - Return slab when empty
- Per-class hints for fast path optimization
3. **Integration** (23 files modified):
- Updated all ss->size_class → meta->class_idx
- Updated all meta->owner_tid → meta->owner_tid_low
- superslab_refill() now uses shared pool
- Free path releases empty slabs back to pool
4. **Build system** (Makefile):
- Added hakmem_shared_pool.o to OBJS_BASE and TINY_BENCH_OBJS_BASE
## Status: ⚠️ Build OK, Runtime CRASH
**Build**: ✅ SUCCESS
- All 23 files compile without errors
- Only warnings: superslab_allocate type mismatch (legacy code)
**Runtime**: ❌ SEGFAULT
- Crash location: sll_refill_small_from_ss()
- Exit code: 139 (SIGSEGV)
- Test case: ./bench_random_mixed_hakmem 1000 256 42
## Known Issues
1. **SEGFAULT in refill path** - Likely shared_pool_acquire_slab() issue
2. **Legacy superslab_allocate()** still exists (type mismatch warning)
3. **Remaining TODOs** from design doc:
- SuperSlab physical layout integration
- slab_handle.h cleanup
- Remove old per-class head implementation
## Next Steps
1. Debug SEGFAULT (gdb backtrace shows sll_refill_small_from_ss)
2. Fix shared_pool_acquire_slab() or superslab_init_slab()
3. Basic functionality test (1K → 100K iterations)
4. Measure SuperSlab count reduction (877 → 100-200)
5. Performance benchmark (+650-860% expected)
## Files Changed (25 files)
core/box/free_local_box.c
core/box/free_remote_box.c
core/box/front_gate_classifier.c
core/hakmem_super_registry.c
core/hakmem_tiny.c
core/hakmem_tiny_bg_spill.c
core/hakmem_tiny_free.inc
core/hakmem_tiny_lifecycle.inc
core/hakmem_tiny_magazine.c
core/hakmem_tiny_query.c
core/hakmem_tiny_refill.inc.h
core/hakmem_tiny_superslab.c
core/hakmem_tiny_superslab.h
core/hakmem_tiny_tls_ops.h
core/slab_handle.h
core/superslab/superslab_inline.h
core/superslab/superslab_types.h
core/tiny_debug.h
core/tiny_free_fast.inc.h
core/tiny_free_magazine.inc.h
core/tiny_remote.c
core/tiny_superslab_alloc.inc.h
core/tiny_superslab_free.inc.h
Makefile
## New Files (3 files)
PHASE12_SHARED_SUPERSLAB_POOL_DESIGN.md
core/hakmem_shared_pool.c
core/hakmem_shared_pool.h
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
Co-Authored-By: ChatGPT <chatgpt@openai.com >
2025-11-13 16:33:03 +09:00
855ea7223c
Phase E1-CORRECT: Fix USER/BASE pointer conversion bugs in slab_index_for calls
...
CRITICAL BUG FIX: Phase E1 introduced 1-byte headers for ALL size classes (C0-C7),
changing the pointer contract. However, many locations still called slab_index_for()
with USER pointers (storage+1) instead of BASE pointers (storage), causing off-by-one
slab index calculations that corrupted memory.
Root Cause:
- USER pointer = BASE + 1 (returned by malloc, points past header)
- BASE pointer = storage start (where 1-byte header is written)
- slab_index_for() expects BASE pointer for correct slab boundary calculations
- Passing USER pointer → wrong slab_idx → wrong metadata → freelist corruption
Impact Before Fix:
- bench_random_mixed crashes at ~14K iterations with SEGV
- Massive C7 alignment check failures (wrong slab classification)
- Memory corruption from writing to wrong slab freelists
Fixes Applied (8 locations):
1. core/hakmem_tiny_free.inc:137
- Added USER→BASE conversion before slab_index_for()
2. core/hakmem_tiny_ultra_simple.inc:148
- Added USER→BASE conversion before slab_index_for()
3. core/tiny_free_fast.inc.h:220
- Added USER→BASE conversion before slab_index_for()
4-5. core/tiny_free_magazine.inc.h:126,315
- Added USER→BASE conversion before slab_index_for() (2 locations)
6. core/box/free_local_box.c:14,22,62
- Added USER→BASE conversion before slab_index_for()
- Fixed delta calculation to use BASE instead of USER
- Fixed debug logging to use BASE instead of USER
7. core/hakmem_tiny.c:448,460,473 (tiny_debug_track_alloc_ret)
- Added USER→BASE conversion before slab_index_for() (2 calls)
- Fixed delta calculation to use BASE instead of USER
- This function is called on EVERY allocation in debug builds
Results After Fix:
✅ bench_random_mixed stable up to 66K iterations (~4.7x improvement)
✅ C7 alignment check failures eliminated (was: 100% failure rate)
✅ Front Gate "Unknown" classification dropped to 0% (was: 1.67%)
✅ No segfaults for workloads up to ~33K allocations
Remaining Issue:
❌ Segfault still occurs at iteration 66152 (allocs=33137, frees=33014)
- Different bug from USER/BASE conversion issues
- Likely capacity/boundary condition (further investigation needed)
Testing:
- bench_random_mixed_hakmem 1K-66K iterations: PASS
- bench_random_mixed_hakmem 67K+ iterations: FAIL (different bug)
- bench_fixed_size_hakmem 200K iterations: PASS
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-13 05:21:36 +09:00
b7021061b8
Fix: CRITICAL double-allocation bug in trc_linear_carve()
...
Root Cause:
trc_linear_carve() used meta->used as cursor, but meta->used decrements
on free, causing already-allocated blocks to be re-carved.
Evidence:
- [LINEAR_CARVE] used=61 batch=1 → block 61 created
- (blocks freed, used decrements 62→59)
- [LINEAR_CARVE] used=59 batch=3 → blocks 59,60,61 RE-CREATED!
- Result: double-allocation → memory corruption → SEGV
Fix Implementation:
1. Added TinySlabMeta.carved (monotonic counter, never decrements)
2. Changed trc_linear_carve() to use carved instead of used
3. carved tracks carve progress, used tracks active count
Files Modified:
- core/superslab/superslab_types.h: Add carved field
- core/tiny_refill_opt.h: Use carved in trc_linear_carve()
- core/hakmem_tiny_superslab.c: Initialize carved=0
- core/tiny_alloc_fast.inc.h: Add next pointer validation
- core/hakmem_tiny_free.inc: Add drain/free validation
Test Results:
✅ bench_random_mixed: 950,037 ops/s (no crash)
✅ Fail-fast mode: 651,627 ops/s (with diagnostic logs)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-08 01:18:37 +09:00
c9053a43ac
Phase 6-2.3~6-2.5: Critical bug fixes + SuperSlab optimization (WIP)
...
## Phase 6-2.3: Fix 4T Larson crash (active counter bug) ✅
**Problem:** 4T Larson crashed with "free(): invalid pointer", OOM errors
**Root cause:** core/hakmem_tiny_refill_p0.inc.h:103
- P0 batch refill moved freelist blocks to TLS cache
- Active counter NOT incremented → double-decrement on free
- Counter underflows → SuperSlab appears full → OOM → crash
**Fix:** Added ss_active_add(tls->ss, from_freelist);
**Result:** 4T stable at 838K ops/s ✅
## Phase 6-2.4: Fix SEGV in random_mixed/mid_large_mt benchmarks ✅
**Problem:** bench_random_mixed_hakmem, bench_mid_large_mt_hakmem → immediate SEGV
**Root cause #1:** core/box/hak_free_api.inc.h:92-95
- "Guess loop" dereferenced unmapped memory when registry lookup failed
**Root cause #2:** core/box/hak_free_api.inc.h:115
- Header magic check dereferenced unmapped memory
**Fix:**
1. Removed dangerous guess loop (lines 92-95)
2. Added hak_is_memory_readable() check before dereferencing header
(core/hakmem_internal.h:277-294 - uses mincore() syscall)
**Result:**
- random_mixed (2KB): SEGV → 2.22M ops/s ✅
- random_mixed (4KB): SEGV → 2.58M ops/s ✅
- Larson 4T: no regression (838K ops/s) ✅
## Phase 6-2.5: Performance investigation + SuperSlab fix (WIP) ⚠️
**Problem:** Severe performance gaps (19-26x slower than system malloc)
**Investigation:** Task agent identified root cause
- hak_is_memory_readable() syscall overhead (100-300 cycles per free)
- ALL frees hit unmapped_header_fallback path
- SuperSlab lookup NEVER called
- Why? g_use_superslab = 0 (disabled by diet mode)
**Root cause:** core/hakmem_tiny_init.inc:104-105
- Diet mode (default ON) disables SuperSlab
- SuperSlab defaults to 1 (hakmem_config.c:334)
- BUT diet mode overrides it to 0 during init
**Fix:** Separate SuperSlab from diet mode
- SuperSlab: Performance-critical (fast alloc/free)
- Diet mode: Memory efficiency (magazine capacity limits only)
- Both are independent features, should not interfere
**Status:** ⚠️ INCOMPLETE - New SEGV discovered after fix
- SuperSlab lookup now works (confirmed via debug output)
- But benchmark crashes (Exit 139) after ~20 lookups
- Needs further investigation
**Files modified:**
- core/hakmem_tiny_init.inc:99-109 - Removed diet mode override
- PERFORMANCE_INVESTIGATION_REPORT.md - Task agent analysis (303x instruction gap)
**Next steps:**
- Investigate new SEGV (likely SuperSlab free path bug)
- OR: Revert Phase 6-2.5 changes if blocking progress
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-07 20:31:01 +09:00
1da8754d45
CRITICAL FIX: TLS 未初期化による 4T SEGV を完全解消
...
**問題:**
- Larson 4T で 100% SEGV (1T は 2.09M ops/s で完走)
- System/mimalloc は 4T で 33.52M ops/s 正常動作
- SS OFF + Remote OFF でも 4T で SEGV
**根本原因: (Task agent ultrathink 調査結果)**
```
CRASH: mov (%r15),%r13
R15 = 0x6261 ← ASCII "ba" (ゴミ値、未初期化TLS)
```
Worker スレッドの TLS 変数が未初期化:
- `__thread void* g_tls_sll_head[TINY_NUM_CLASSES];` ← 初期化なし
- pthread_create() で生成されたスレッドでゼロ初期化されない
- NULL チェックが通過 (0x6261 != NULL) → dereference → SEGV
**修正内容:**
全 TLS 配列に明示的初期化子 `= {0}` を追加:
1. **core/hakmem_tiny.c:**
- `g_tls_sll_head[TINY_NUM_CLASSES] = {0}`
- `g_tls_sll_count[TINY_NUM_CLASSES] = {0}`
- `g_tls_live_ss[TINY_NUM_CLASSES] = {0}`
- `g_tls_bcur[TINY_NUM_CLASSES] = {0}`
- `g_tls_bend[TINY_NUM_CLASSES] = {0}`
2. **core/tiny_fastcache.c:**
- `g_tiny_fast_cache[TINY_FAST_CLASS_COUNT] = {0}`
- `g_tiny_fast_count[TINY_FAST_CLASS_COUNT] = {0}`
- `g_tiny_fast_free_head[TINY_FAST_CLASS_COUNT] = {0}`
- `g_tiny_fast_free_count[TINY_FAST_CLASS_COUNT] = {0}`
3. **core/hakmem_tiny_magazine.c:**
- `g_tls_mags[TINY_NUM_CLASSES] = {0}`
4. **core/tiny_sticky.c:**
- `g_tls_sticky_ss[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
- `g_tls_sticky_idx[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
- `g_tls_sticky_pos[TINY_NUM_CLASSES] = {0}`
**効果:**
```
Before: 1T: 2.09M ✅ | 4T: SEGV 💀
After: 1T: 2.41M ✅ | 4T: 4.19M ✅ (+15% 1T, SEGV解消)
```
**テスト:**
```bash
# 1 thread: 完走
./larson_hakmem 2 8 128 1024 1 12345 1
→ Throughput = 2,407,597 ops/s ✅
# 4 threads: 完走（以前は SEGV）
./larson_hakmem 2 8 128 1024 1 12345 4
→ Throughput = 4,192,155 ops/s ✅
```
**調査協力:** Task agent (ultrathink mode) による完璧な根本原因特定
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-07 01:27:04 +09:00
