6154e7656c
根治修正: unified_cache_refill SEGVAULT + コンパイラ最適化対策
...
問題:
- リリース版sh8benchでunified_cache_refill+0x46fでSEGVAULT
- コンパイラ最適化により、ヘッダー書き込みとtiny_next_read()の
順序が入れ替わり、破損したポインタをout[]に格納
根本原因:
- ヘッダー書き込みがtiny_next_read()の後にあった
- volatile barrierがなく、コンパイラが自由に順序を変更
- ASan版では最適化が制限されるため問題が隠蔽されていた
修正内容(P1-P3):
P1: unified_cache_refill SEGVAULT修正 (core/front/tiny_unified_cache.c:341-350)
- ヘッダー書き込みをtiny_next_read()の前に移動
- __atomic_thread_fence(__ATOMIC_RELEASE)追加
- コンパイラ最適化による順序入れ替えを防止
P2: 二重書き込み削除 (core/box/tiny_front_cold_box.h:75-82)
- tiny_region_id_write_header()削除
- unified_cache_refillが既にヘッダー書き込み済み
- 不要なメモリ操作を削除して効率化
P3: tiny_next_read()安全性強化 (core/tiny_nextptr.h:73-86)
- __atomic_thread_fence(__ATOMIC_ACQUIRE)追加
- メモリ操作の順序を保証
P4: ヘッダー書き込みデフォルトON (core/tiny_region_id.h - ChatGPT修正)
- g_write_headerのデフォルトを1に変更
- HAKMEM_TINY_WRITE_HEADER=0で旧挙動に戻せる
テスト結果:
✅ unified_cache_refill SEGVAULT: 解消(sh8bench実行可能に)
❌ TLS_SLL_HDR_RESET: まだ発生中(別の根本原因、調査継続)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-12-03 09:57:12 +09:00
c04cccf723
Phase 6-A: Clarify debug-only validation (code readability, no perf change)
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Explicitly guard SuperSlab validation with #if !HAKMEM_BUILD_RELEASE
to document that this code is debug-only.
Changes:
- core/tiny_region_id.h: Add #if !HAKMEM_BUILD_RELEASE guard around
hak_super_lookup() validation code (lines 199-239)
- Improves code readability: Makes debug-only intent explicit
- Self-documenting: No need to check Makefile to understand behavior
- Defensive: Works correctly even if LTO is disabled
Performance Impact:
- Measured: +1.67% (bench_random_mixed), +1.33% (bench_mid_mt_gap)
- Expected: +12-15% (based on initial perf interpretation)
- Actual: NO measurable improvement (within noise margin ±3.6%)
Root Cause (Investigation):
- Compiler (LTO) already eliminated hak_super_lookup() automatically
- The function never existed in compiled binary (verified via nm/objdump)
- Default Makefile has -DHAKMEM_BUILD_RELEASE=1 + -flto
- perf's "15.84% CPU" was misattributed (was free(), not hak_super_lookup)
Conclusion:
This change provides NO performance benefit, but IMPROVES code clarity
by making the debug-only nature explicit rather than relying on
implicit compiler optimization.
Files:
- core/tiny_region_id.h - Add explicit debug guard
- PHASE6A_DISCREPANCY_INVESTIGATION.md - Full investigation report
Lessons Learned:
1. Always verify assembly output before claiming optimizations
2. perf attribution can be misleading - cross-reference with symbols
3. LTO is extremely aggressive at dead code elimination
4. Small improvements (<2× stdev) need statistical validation
See PHASE6A_DISCREPANCY_INVESTIGATION.md for complete analysis.
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-29 15:22:31 +09:00
20f8d6f179
Cleanup: Add tiny_debug_api.h to eliminate guard/failfast implicit warnings
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Created central header for debug instrumentation API to fix implicit
function declaration warnings across the codebase.
Changes:
1. Created core/tiny_debug_api.h
- Declares guard system API (3 functions)
- Declares failfast debugging API (3 functions)
- Uses forward declarations for SuperSlab/TinySlabMeta
2. Updated 3 files to include tiny_debug_api.h:
- core/tiny_region_id.h (removed inline externs)
- core/hakmem_tiny_tls_ops.h
- core/tiny_superslab_alloc.inc.h
Warnings eliminated (6 of 11 total):
✅ tiny_guard_is_enabled()
✅ tiny_guard_on_alloc()
✅ tiny_guard_on_invalid()
✅ tiny_failfast_log()
✅ tiny_failfast_abort_ptr()
✅ tiny_refill_failfast_level()
Remaining warnings (deferred to P1):
- ss_active_add (2 occurrences)
- expand_superslab_head
- hkm_ace_set_tls_capacity
- smallmid_backend_free
Impact:
- Cleaner build output
- Better type safety for debug functions
- No behavior changes
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-29 06:47:13 +09:00
6ac6f5ae1b
Refactor: Split hakmem_tiny_superslab.c + unified backend exit point
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Major refactoring to improve maintainability and debugging:
1. Split hakmem_tiny_superslab.c (1521 lines) into 7 focused files:
- superslab_allocate.c: SuperSlab allocation/deallocation
- superslab_backend.c: Backend allocation paths (legacy, shared)
- superslab_ace.c: ACE (Adaptive Cache Engine) logic
- superslab_slab.c: Slab initialization and bitmap management
- superslab_cache.c: LRU cache and prewarm cache management
- superslab_head.c: SuperSlabHead management and expansion
- superslab_stats.c: Statistics tracking and debugging
2. Created hakmem_tiny_superslab_internal.h for shared declarations
3. Added superslab_return_block() as single exit point for header writing:
- All backend allocations now go through this helper
- Prevents bugs where headers are forgotten in some paths
- Makes future debugging easier
4. Updated Makefile for new file structure
5. Added header writing to ss_legacy_backend_box.c and
ss_unified_backend_box.c (though not currently linked)
Note: Header corruption bug in Larson benchmark still exists.
Class 1-6 allocations go through TLS refill/carve paths, not backend.
Further investigation needed.
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-29 05:13:04 +09:00
912123cbbe
P3: Skip header write in alloc path when class_map is active
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Skip the 1-byte header write in tiny_region_id_write_header() when class_map
is active (default). class_map provides out-of-band class_idx lookup, making
the header byte unnecessary for the free path.
Changes:
- Add ENV-gated conditional to skip header write (default: skip)
- ENV: HAKMEM_TINY_WRITE_HEADER=1 to force header write (legacy mode)
- Memory layout preserved: user pointer = base + 1 (1B unused when skipped)
Performance improvement:
- tiny_hot 64B: 83.5M → 84.2M ops/sec (+0.8%)
- random_mixed ws=256: 68.1M → 72.2M ops/sec (+6%)
The header skip reduces one store instruction per allocation, which is
particularly beneficial for mixed-size workloads like random_mixed.
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-28 14:46:55 +09:00
316ea4dfd6
ENV Cleanup Step 4: Gate HAKMEM_WATCH_ADDR in tiny_region_id.h
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Gate get_watch_addr() debug functionality with HAKMEM_BUILD_RELEASE,
returning 0 in release builds to disable address watching overhead.
Performance: 30.31M ops/s (baseline: 30.2M)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-28 00:47:16 +09:00
0a8bdb8b18
Fix release build debug logging in tiny_region_id.h
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The allocation logging at line 236-249 was missing the
#if !HAKMEM_BUILD_RELEASE guard, causing fprintf(stderr)
on every allocation even in release builds.
Impact: 19.8M ops/s → 28.0M ops/s (+42%)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-27 11:58:00 +09:00
d8e3971dc2
Fix cross-thread ownership check: Use bits 8-15 for owner_tid_low
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Problem:
- TLS_SLL_PUSH_DUP crash in Larson multi-threaded benchmark
- Cross-thread frees incorrectly routed to same-thread TLS path
- Root cause: pthread_t on glibc is 256-byte aligned (TCB base)
so lower 8 bits are ALWAYS 0x00 for ALL threads
Fix:
- Change owner_tid_low from (tid & 0xFF) to ((tid >> 8) & 0xFF)
- Bits 8-15 actually vary between threads, enabling correct detection
- Applied consistently across all ownership check locations:
- superslab_inline.h: ss_owner_try_acquire/release/is_mine
- slab_handle.h: slab_try_acquire
- tiny_free_fast.inc.h: tiny_free_is_same_thread_ss
- tiny_free_fast_v2.inc.h: cross-thread detection
- tiny_superslab_free.inc.h: same-thread check
- ss_allocation_box.c: slab initialization
- hakmem_tiny_superslab.c: ownership handling
Also added:
- Address watcher debug infrastructure (tiny_region_id.h)
- Cross-thread detection in malloc_tiny_fast.h Front Gate
Test results:
- Larson 1T/2T/4T: PASS (no TLS_SLL_PUSH_DUP crash)
- random_mixed: PASS
- Performance: ~20M ops/s (regression from 48M, needs optimization)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-27 11:52:11 +09:00
25d963a4aa
Code Cleanup: Remove false positives, redundant validations, and reduce verbose logging
...
Following the C7 stride upgrade fix (commit 23c0d9541 ), this commit performs
comprehensive cleanup to improve code quality and reduce debug noise.
## Changes
### 1. Disable False Positive Checks (tiny_nextptr.h)
- **Disabled**: NXT_MISALIGN validation block with `#if 0`
- **Reason**: Produces false positives due to slab base offsets (2048, 65536)
not being stride-aligned, causing all blocks to appear "misaligned"
- **TODO**: Reimplement to check stride DISTANCE between consecutive blocks
instead of absolute alignment to stride boundaries
### 2. Remove Redundant Geometry Validations
**hakmem_tiny_refill_p0.inc.h (P0 batch refill)**
- Removed 25-line CARVE_GEOMETRY_FIX validation block
- Replaced with NOTE explaining redundancy
- **Reason**: Stride table is now correct in tiny_block_stride_for_class(),
defense-in-depth validation adds overhead without benefit
**ss_legacy_backend_box.c (legacy backend)**
- Removed 18-line LEGACY_FIX_GEOMETRY validation block
- Replaced with NOTE explaining redundancy
- **Reason**: Shared_pool validates geometry at acquisition time
### 3. Reduce Verbose Logging
**hakmem_shared_pool.c (sp_fix_geometry_if_needed)**
- Made SP_FIX_GEOMETRY logging conditional on `!HAKMEM_BUILD_RELEASE`
- **Reason**: Geometry fixes are expected during stride upgrades,
no need to log in release builds
### 4. Verification
- Build: ✅ 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
72b38bc994
Phase E3-FINAL: Fix Box API offset bugs - ALL classes now use correct offsets
...
## Root Cause Analysis (GPT5)
**Physical Layout Constraints**:
- Class 0: 8B = [1B header][7B payload] → offset 1 = 9B needed = ❌ IMPOSSIBLE
- Class 1-6: >=16B = [1B header][15B+ payload] → offset 1 = ✅ POSSIBLE
- Class 7: 1KB → offset 0 (compatibility)
**Correct Specification**:
- HAKMEM_TINY_HEADER_CLASSIDX != 0:
- Class 0, 7: next at offset 0 (overwrites header when on freelist)
- Class 1-6: next at offset 1 (after header)
- HAKMEM_TINY_HEADER_CLASSIDX == 0:
- All classes: next at offset 0
**Previous Bug**:
- Attempted "ALL classes offset 1" unification
- Class 0 with offset 1 caused immediate SEGV (9B > 8B block size)
- Mixed 2-arg/3-arg API caused confusion
## Fixes Applied
### 1. Restored 3-Argument Box API (core/box/tiny_next_ptr_box.h)
```c
// Correct signatures
void tiny_next_write(int class_idx, void* base, void* next_value)
void* tiny_next_read(int class_idx, const void* base)
// Correct offset calculation
size_t offset = (class_idx == 0 || class_idx == 7) ? 0 : 1;
```
### 2. Updated 123+ Call Sites Across 34 Files
- hakmem_tiny_hot_pop_v4.inc.h (4 locations)
- hakmem_tiny_fastcache.inc.h (3 locations)
- hakmem_tiny_tls_list.h (12 locations)
- superslab_inline.h (5 locations)
- tiny_fastcache.h (3 locations)
- ptr_trace.h (macro definitions)
- tls_sll_box.h (2 locations)
- + 27 additional files
Pattern: `tiny_next_read(base)` → `tiny_next_read(class_idx, base)`
Pattern: `tiny_next_write(base, next)` → `tiny_next_write(class_idx, base, next)`
### 3. Added Sentinel Detection Guards
- tiny_fast_push(): Block nodes with sentinel in ptr or ptr->next
- tls_list_push(): Block nodes with sentinel in ptr or ptr->next
- Defense-in-depth against remote free sentinel leakage
## Verification (GPT5 Report)
**Test Command**: `./out/release/bench_random_mixed_hakmem --iterations=70000`
**Results**:
- ✅ Main loop completed successfully
- ✅ Drain phase completed successfully
- ✅ NO SEGV (previous crash at iteration 66151 is FIXED)
- ℹ️ Final log: "tiny_alloc(1024) failed" is normal fallback to Mid/ACE layers
**Analysis**:
- Class 0 immediate SEGV: ✅ RESOLVED (correct offset 0 now used)
- 66K iteration crash: ✅ RESOLVED (offset consistency fixed)
- Box API conflicts: ✅ RESOLVED (unified 3-arg API)
## Technical Details
### Offset Logic Justification
```
Class 0: 8B block → next pointer (8B) fits ONLY at offset 0
Class 1: 16B block → next pointer (8B) fits at offset 1 (after 1B header)
Class 2: 32B block → next pointer (8B) fits at offset 1
...
Class 6: 512B block → next pointer (8B) fits at offset 1
Class 7: 1024B block → offset 0 for legacy compatibility
```
### Files Modified (Summary)
- Core API: `box/tiny_next_ptr_box.h`
- Hot paths: `hakmem_tiny_hot_pop*.inc.h`, `tiny_fastcache.h`
- TLS layers: `hakmem_tiny_tls_list.h`, `hakmem_tiny_tls_ops.h`
- SuperSlab: `superslab_inline.h`, `tiny_superslab_*.inc.h`
- Refill: `hakmem_tiny_refill.inc.h`, `tiny_refill_opt.h`
- Free paths: `tiny_free_magazine.inc.h`, `tiny_superslab_free.inc.h`
- Documentation: Multiple Phase E3 reports
## Remaining Work
None for Box API offset bugs - all structural issues resolved.
Future enhancements (non-critical):
- Periodic `grep -R '*(void**)' core/` to detect direct pointer access violations
- Enforce Box API usage via static analysis
- Document offset rationale in architecture docs
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-13 06:50:20 +09:00
84dbd97fe9
Fix #16 : Resolve double BASE→USER conversion causing header corruption
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🎯 ROOT CAUSE: Internal allocation helpers were prematurely converting
BASE → USER pointers before returning to caller. The caller then applied
HAK_RET_ALLOC/tiny_region_id_write_header which performed ANOTHER BASE→USER
conversion, resulting in double offset (BASE+2) and header written at
wrong location.
📦 BOX THEORY SOLUTION: Establish clean pointer conversion boundary at
tiny_region_id_write_header, making it the single source of truth for
BASE → USER conversion.
🔧 CHANGES:
- Fix #16 : Remove premature BASE→USER conversions (6 locations)
* core/tiny_alloc_fast.inc.h (3 fixes)
* core/hakmem_tiny_refill.inc.h (2 fixes)
* core/hakmem_tiny_fastcache.inc.h (1 fix)
- Fix #12 : Add header validation in tls_sll_pop (detect corruption)
- Fix #14 : Defense-in-depth header restoration in tls_sll_splice
- Fix #15 : USER pointer detection (for debugging)
- Fix #13 : Bump window header restoration
- Fix #2 , #6 , #7 , #8 : Various header restoration & NULL termination
🧪 TEST RESULTS: 100% SUCCESS
- 10K-500K iterations: All passed
- 8 seeds × 100K: All passed (42,123,456,789,999,314,271,161)
- Performance: ~630K ops/s average (stable)
- Header corruption: ZERO
📋 FIXES SUMMARY:
Fix #1-8: Initial header restoration & chain fixes (chatgpt-san)
Fix #9-10: USER pointer auto-fix (later disabled)
Fix #12 : Validation system (caught corruption at call 14209)
Fix #13 : Bump window header writes
Fix #14 : Splice defense-in-depth
Fix #15 : USER pointer detection (debugging tool)
Fix #16 : Double conversion fix (FINAL SOLUTION) ✅
🎓 LESSONS LEARNED:
1. Validation catches bugs early (Fix #12 was critical)
2. Class-specific inline logging reveals patterns (Option C)
3. Box Theory provides clean architectural boundaries
4. Multiple investigation approaches (Task/chatgpt-san collaboration)
📄 DOCUMENTATION:
- P0_BUG_STATUS.md: Complete bug tracking timeline
- C2_CORRUPTION_ROOT_CAUSE_FINAL.md: Detailed root cause analysis
- FINAL_ANALYSIS_C2_CORRUPTION.md: Investigation methodology
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
Co-Authored-By: Task Agent <task@anthropic.com >
Co-Authored-By: ChatGPT <chatgpt@openai.com >
2025-11-12 10:33:57 +09:00
dde490f842
Phase 7: header-aware TLS front caches and FG gating
...
- core/hakmem_tiny_fastcache.inc.h: make tiny_fast_pop/push read/write next at base+1 for C0–C6; clear C7 next on pop
- core/hakmem_tiny_hot_pop.inc.h: header-aware next reads for g_fast_head pops (classes 0–3)
- core/tiny_free_magazine.inc.h: header-aware chain linking for BG spill chain (base+1 for C0–C6)
- core/box/front_gate_classifier.c: registry fallback classifies headerless only for class 7; others as headered
Build OK; bench_fixed_size_hakmem still SIGBUS right after init. FREE_ROUTE trace shows invalid frees (ptr=0xa0, etc.). Next steps: instrument early frees and audit remaining header-aware writes in any front caches not yet patched.
2025-11-10 18:04:08 +09:00
1010a961fb
Tiny: fix header/stride mismatch and harden refill paths
...
- Root cause: header-based class indexing (HEADER_CLASSIDX=1) wrote a 1-byte
header during allocation, but linear carve/refill and initial slab capacity
still used bare class block sizes. This mismatch could overrun slab usable
space and corrupt freelists, causing reproducible SEGV at ~100k iters.
Changes
- Superslab: compute capacity with effective stride (block_size + header for
classes 0..6; class7 remains headerless) in superslab_init_slab(). Add a
debug-only bound check in superslab_alloc_from_slab() to fail fast if carve
would exceed usable bytes.
- Refill (non-P0 and P0): use header-aware stride for all linear carving and
TLS window bump operations. Ensure alignment/validation in tiny_refill_opt.h
also uses stride, not raw class size.
- Drain: keep existing defense-in-depth for remote sentinel and sanitize nodes
before splicing into freelist (already present).
Notes
- This unifies the memory layout across alloc/linear-carve/refill with a single
stride definition and keeps class7 (1024B) headerless as designed.
- Debug builds add fail-fast checks; release builds remain lean.
Next
- Re-run Tiny benches (256/1024B) in debug to confirm stability, then in
release. If any remaining crash persists, bisect with HAKMEM_TINY_P0_BATCH_REFILL=0
to isolate P0 batch carve, and continue reducing branch-miss as planned.
2025-11-09 18:55:50 +09:00
0da9f8cba3
Phase 7 + Pool TLS 1.5b stabilization:\n- Add build hygiene (dep tracking, flag consistency, print-flags)\n- Add build.sh + verify_build.sh (unified recipe, freshness check)\n- Quiet verbose logs behind HAKMEM_DEBUG_VERBOSE\n- A/B free safety via HAKMEM_TINY_SAFE_FREE (mincore strict vs boundary)\n- Tweak Tiny header path to reduce noise; Pool TLS free guard optimized\n- Fix mimalloc link retention (--no-as-needed + force symbol)\n- Add docs/BUILD_PHASE7_POOL_TLS.md (cheatsheet)
2025-11-09 11:50:18 +09:00
7975e243ee
Phase 7 Task 3: Pre-warm TLS cache (+180-280% improvement!)
...
MAJOR SUCCESS: HAKMEM now achieves 85-92% of System malloc on tiny
allocations (128-512B) and BEATS System at 146% on 1024B allocations!
Performance Results:
- Random Mixed 128B: 21M → 59M ops/s (+181%) 🚀
- Random Mixed 256B: 19M → 70M ops/s (+268%) 🚀
- Random Mixed 512B: 21M → 68M ops/s (+224%) 🚀
- Random Mixed 1024B: 21M → 65M ops/s (+210%, 146% of System!) 🏆
- Larson 1T: 2.68M ops/s (stable, no regression)
Implementation:
1. Task 3a: Remove profiling overhead in release builds
- Wrapped RDTSC calls in #if !HAKMEM_BUILD_RELEASE
- Compiler can eliminate profiling code completely
- Effect: +2% (2.68M → 2.73M Larson)
2. Task 3b: Simplify refill logic
- Use constants from hakmem_build_flags.h
- TLS cache already optimal
- Effect: No regression
3. Task 3c: Pre-warm TLS cache (GAME CHANGER!)
- Pre-allocate 16 blocks per class at init
- Eliminates cold-start penalty
- Effect: +180-280% improvement 🚀
Root Cause:
The bottleneck was cold-start, not the hot path! First allocation in
each class triggered a SuperSlab refill (100+ cycles). Pre-warming
eliminated this penalty, revealing Phase 7's true potential.
Files Modified:
- core/hakmem_tiny.c: Pre-warm function implementation
- core/box/hak_core_init.inc.h: Pre-warm initialization call
- core/tiny_alloc_fast.inc.h: Profiling overhead removal
- core/hakmem_phase7_config.h: Task 3 constants (NEW)
- core/hakmem_build_flags.h: Phase 7 feature flags
- Makefile: PREWARM_TLS flag, phase7 targets
- CLAUDE.md: Phase 7 success summary
- PHASE7_TASK3_RESULTS.md: Comprehensive results report (NEW)
Build:
make HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 PREWARM_TLS=1 phase7-bench
🎉 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-08 12:54:52 +09:00
4983352812
Perf: Phase 7-1.3 - Hybrid mincore + Macro fix (+194-333%)
...
## Summary
Fixed CRITICAL bottleneck (mincore overhead) and macro definition bug.
Result: 2-3x performance improvement across all benchmarks.
## Performance Results
- Larson 1T: 631K → 2.73M ops/s (+333%) 🚀
- bench_random_mixed (128B): 768K → 2.26M ops/s (+194%) 🚀
- bench_random_mixed (512B): → 1.43M ops/s (new)
- [HEADER_INVALID] messages: Many → ~Zero ✅
## Changes
### 1. Hybrid mincore Optimization (317-634x faster)
**Problem**: `hak_is_memory_readable()` calls mincore() syscall on EVERY free
- Cost: 634 cycles/call
- Impact: 40x slower than System malloc
**Solution**: Check alignment BEFORE calling mincore()
- Step 1 (1-byte header): `if ((ptr & 0xFFF) == 0)` → only 0.1% call mincore
- Step 2 (16-byte header): `if ((ptr & 0xFFF) < HEADER_SIZE)` → only 0.4% call mincore
- Result: 634 → 1-2 cycles effective (99.6% skip mincore)
**Files**:
- core/tiny_free_fast_v2.inc.h:53-71 - Step 1 hybrid check
- core/box/hak_free_api.inc.h:94-107 - Step 2 hybrid check
- core/hakmem_internal.h:281-312 - Performance warning added
### 2. HAK_RET_ALLOC Macro Fix (CRITICAL BUG)
**Problem**: Macro definition order prevented Phase 7 header write
- hakmem_tiny.c:130 defined legacy macro (no header write)
- tiny_alloc_fast.inc.h:67 had `#ifndef` guard → skipped!
- Result: Headers NEVER written → All frees failed → Slow path
**Solution**: Force Phase 7 macro to override legacy
- hakmem_tiny.c:119 - Added `#ifndef HAK_RET_ALLOC` guard
- tiny_alloc_fast.inc.h:69-72 - Added `#undef` before redefine
### 3. Magic Byte Fix
**Problem**: Release builds don't write magic byte, but free ALWAYS checks it
- Result: All headers marked as invalid
**Solution**: ALWAYS write magic byte (same 1-byte write, no overhead)
- tiny_region_id.h:50-54 - Removed `#if !HAKMEM_BUILD_RELEASE` guard
## Technical Details
### Hybrid mincore Effectiveness
| Case | Frequency | Cost | Weighted |
|------|-----------|------|----------|
| Normal (Step 1) | 99.9% | 1-2 cycles | 1-2 |
| Page boundary | 0.1% | 634 cycles | 0.6 |
| **Total** | - | - | **1.6-2.6 cycles** |
**Improvement**: 634 → 1.6 cycles = **317-396x faster!**
### Macro Fix Impact
**Before**: HAK_RET_ALLOC(cls, ptr) → return (ptr) // No header write
**After**: HAK_RET_ALLOC(cls, ptr) → return tiny_region_id_write_header((ptr), (cls))
**Result**: Headers properly written → Fast path works → +194-333% performance
## Investigation
Task Agent Ultrathink analysis identified:
1. mincore() syscall overhead (634 cycles)
2. Macro definition order conflict
3. Release/Debug build mismatch (magic byte)
Full report: PHASE7_DESIGN_REVIEW.md (23KB, 758 lines)
## Related
- Phase 7-1.0: PoC implementation (+39%~+436%)
- Phase 7-1.1: Dual-header dispatch (Task Agent)
- Phase 7-1.2: Page boundary SEGV fix (100% crash-free)
- Phase 7-1.3: Hybrid mincore + Macro fix (this commit)
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-08 04:50:41 +09:00
48fadea590
Phase 7-1.1: Fix 1024B crash (header validation + malloc fallback)
...
Fixed critical bugs preventing Phase 7 from working with 1024B allocations.
## Bug Fixes (by Task Agent Ultrathink)
1. **Header Validation Missing in Release Builds**
- `core/tiny_region_id.h:73-97` - Removed `#if !HAKMEM_BUILD_RELEASE`
- Always validate magic byte and class_idx (prevents SEGV on Mid/Large)
2. **1024B Malloc Fallback Missing**
- `core/box/hak_alloc_api.inc.h:35-49` - Direct fallback to malloc
- Phase 7 rejects 1024B (needs header) → skip ACE → use malloc
## Test Results
| Test | Result |
|------|--------|
| 128B, 512B, 1023B (Tiny) | +39%~+436% ✅ |
| 1024B only (100 allocs) | 100% success ✅ |
| Mixed 128B+1024B (200) | 100% success ✅ |
| bench_random_mixed 1024B | Still crashes ❌ |
## Known Issue
`bench_random_mixed` with 1024B still crashes (intermittent SEGV).
Simple tests pass, suggesting issue is with complex allocation patterns.
Investigation pending.
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
Co-Authored-By: Task Agent Ultrathink
2025-11-08 03:35:07 +09:00
6b1382959c
Phase 7-1 PoC: Region-ID Direct Lookup (+39%~+436% improvement!)
...
Implemented ultra-fast header-based free path that eliminates SuperSlab
lookup bottleneck (100+ cycles → 5-10 cycles).
## Key Changes
1. **Smart Headers** (core/tiny_region_id.h):
- 1-byte header before each allocation stores class_idx
- Memory layout: [Header: 1B] [User data: N-1B]
- Overhead: <2% average (0% for Slab[0] using wasted padding)
2. **Ultra-Fast Allocation** (core/tiny_alloc_fast.inc.h):
- Write header at base: *base = class_idx
- Return user pointer: base + 1
3. **Ultra-Fast Free** (core/tiny_free_fast_v2.inc.h):
- Read class_idx from header (ptr-1): 2-3 cycles
- Push base (ptr-1) to TLS freelist: 3-5 cycles
- Total: 5-10 cycles (vs 500+ cycles current!)
4. **Free Path Integration** (core/box/hak_free_api.inc.h):
- Removed SuperSlab lookup from fast path
- Direct header validation (no lookup needed!)
5. **Size Class Adjustment** (core/hakmem_tiny.h):
- Max tiny size: 1023B (was 1024B)
- 1024B requests → Mid allocator fallback
## Performance Results
| Size | Baseline | Phase 7 | Improvement |
|------|----------|---------|-------------|
| 128B | 1.22M | 6.54M | **+436%** 🚀 |
| 512B | 1.22M | 1.70M | **+39%** |
| 1023B | 1.22M | 1.92M | **+57%** |
## Build & Test
Enable Phase 7:
make HEADER_CLASSIDX=1 bench_random_mixed_hakmem
Run benchmark:
HAKMEM_TINY_USE_SUPERSLAB=1 ./bench_random_mixed_hakmem 10000 128 1234567
## Known Issues
- 1024B requests fallback to Mid allocator (by design)
- Target 40-60M ops/s not yet reached (current: 1.7-6.5M)
- Further optimization needed (TLS capacity tuning, refill optimization)
## Credits
Design: ChatGPT Pro Ultrathink, Claude Code
Implementation: Claude Code with Task Agent Ultrathink support
🤖 Generated with [Claude Code](https://claude.com/claude-code )
Co-Authored-By: Claude <noreply@anthropic.com >
2025-11-08 03:18:17 +09:00