Commit Graph

10 Commits

Author SHA1 Message Date
19056282b6 Phase 3 D2: Wrapper Env Cache - [DECISION: NO-GO]
Target: Reduce wrapper_env_cfg() overhead in malloc/free hot path
- Strategy: Cache wrapper env configuration pointer in TLS
- Approach: Fast pointer cache (TLS caches const wrapper_env_cfg_t*)

Implementation:
- core/box/wrapper_env_cache_env_box.h: ENV gate (HAKMEM_WRAP_ENV_CACHE)
- core/box/wrapper_env_cache_box.h: TLS cache layer (wrapper_env_cfg_fast)
- core/box/hak_wrappers.inc.h: Integration into malloc/free hot paths
- ENV gate: HAKMEM_WRAP_ENV_CACHE=0/1 (default OFF)

A/B Test Results (Mixed, 10-run, 20M iters):
- Baseline (D2=0): 46.52M ops/s (avg), 46.47M ops/s (median)
- Optimized (D2=1): 45.85M ops/s (avg), 45.98M ops/s (median)
- Improvement: avg -1.44%, median -1.05% (DECISION: NO-GO)

Analysis:
- Regression cause: TLS cache adds overhead (branch + TLS access)
- wrapper_env_cfg() is already minimal (pointer return after simple check)
- Adding TLS caching layer makes it worse, not better
- Branch prediction penalty outweighs any potential savings

Cumulative Phase 2-3:
- B3: +2.89%, B4: +1.47%, C3: +2.20%
- D1: +1.06% (opt-in), D2: -1.44% (NO-GO)
- Total: ~7.2% (excluding D2)

Decision: FREEZE as research box (default OFF, regression confirmed)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-13 22:03:27 +09:00
acc64f2438 Phase ML1: Pool v1 memset 89.73% overhead 軽量化 (+15.34% improvement)
## Summary
- ChatGPT により bench_profile.h の setenv segfault を修正(RTLD_NEXT 経由に切り替え)
- core/box/pool_zero_mode_box.h 新設:ENV キャッシュ経由で ZERO_MODE を統一管理
- core/hakmem_pool.c で zero mode に応じた memset 制御(FULL/header/off)
- A/B テスト結果:ZERO_MODE=header で +15.34% improvement(1M iterations, C6-heavy)

## Files Modified
- core/box/pool_api.inc.h: pool_zero_mode_box.h include
- core/bench_profile.h: glibc setenv → malloc+putenv(segfault 回避)
- core/hakmem_pool.c: zero mode 参照・制御ロジック
- core/box/pool_zero_mode_box.h (新設): enum/getter
- CURRENT_TASK.md: Phase ML1 結果記載

## Test Results
| Iterations | ZERO_MODE=full | ZERO_MODE=header | Improvement |
|-----------|----------------|-----------------|------------|
| 10K       | 3.06 M ops/s   | 3.17 M ops/s    | +3.65%     |
| 1M        | 23.71 M ops/s  | 27.34 M ops/s   | **+15.34%** |

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-10 09:08:18 +09:00
fda6cd2e67 Boxify superslab registry, add bench profile, and document C7 hotpath experiments 2025-12-07 03:12:27 +09:00
bcfb4f6b59 Remove dead code: UltraHot, RingCache, FrontC23, Class5 Hotpath
(cherry-picked from 225b6fcc7, conflicts resolved)
2025-11-26 12:33:49 +09:00
fcf098857a Phase12 debug: restore SUPERSLAB constants/APIs, implement Box2 drain boundary, fix tiny_fast_pop to return BASE, honor TLS SLL toggle in alloc/free fast paths, add fail-fast stubs, and quiet capacity sentinel. Update CURRENT_TASK with A/B results (SLL-off stable; SLL-on crash). 2025-11-14 01:02:00 +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
862e8ea7db Infrastructure and build updates
- Update build configuration and flags
- Add missing header files and dependencies
- Update TLS list implementation with proper scoping
- Fix various compilation warnings and issues
- Update debug ring and tiny allocation infrastructure
- Update benchmark results documentation

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
2025-11-11 21:49:05 +09:00
1b6624dec4 Fix debug build: gate Tiny observation snapshot in hakmem_tiny_stats.c behind HAKMEM_TINY_OBS_ENABLE to avoid incomplete TinyObsStats and missing globals. Now debug build passes, enabling C7 triage with fail‑fast guards. 2025-11-10 03:00:00 +09:00
d9b334b968 Tiny: Enable P0 batch refill by default + docs and task update
Summary
- Default P0 ON: Build-time HAKMEM_TINY_P0_BATCH_REFILL=1 remains; runtime gate now defaults to ON
  (HAKMEM_TINY_P0_ENABLE unset or not '0'). Kill switch preserved via HAKMEM_TINY_P0_DISABLE=1.
- Fix critical bug: After freelist→SLL batch splice, increment TinySlabMeta::used by 'from_freelist'
  to mirror non-P0 behavior (prevents under-accounting and follow-on carve invariants from breaking).
- Add low-overhead A/B toggles for triage: HAKMEM_TINY_P0_NO_DRAIN (skip remote drain),
  HAKMEM_TINY_P0_LOG (emit [P0_COUNTER_OK/MISMATCH] based on total_active_blocks delta).
- Keep linear carve fail-fast guards across simple/general/TLS-bump paths.

Perf (1T, 100k×256B)
- P0 OFF: ~2.73M ops/s (stable)
- P0 ON (no drain): ~2.45M ops/s
- P0 ON (normal drain): ~2.76M ops/s (fastest)

Known
- Rare [P0_COUNTER_MISMATCH] warnings persist (non-fatal). Continue auditing active/used
  balance around batch freelist splice and remote drain splice.

Docs
- Add docs/TINY_P0_BATCH_REFILL.md (runtime switches, behavior, perf notes).
- Update CURRENT_TASK.md with Tiny P0 status (default ON) and next steps.
2025-11-09 22:12:34 +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