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hakmem/docs/analysis/ENV_CLEANUP_SUMMARY.md
Moe Charm (CI) 43015725af ENV cleanup: Add RELEASE guards to DEBUG ENV variables (14 vars) 
Added compile-time guards (#if HAKMEM_BUILD_RELEASE) to eliminate
DEBUG ENV variable overhead in RELEASE builds.

Variables guarded (14 total):
- HAKMEM_TINY_TRACE_RING, HAKMEM_TINY_DUMP_RING_ATEXIT
- HAKMEM_TINY_RF_TRACE, HAKMEM_TINY_MAILBOX_TRACE
- HAKMEM_TINY_MAILBOX_TRACE_LIMIT, HAKMEM_TINY_MAILBOX_SLOWDISC
- HAKMEM_TINY_MAILBOX_SLOWDISC_PERIOD
- HAKMEM_SS_PREWARM_DEBUG, HAKMEM_SS_FREE_DEBUG
- HAKMEM_TINY_FRONT_METRICS, HAKMEM_TINY_FRONT_DUMP
- HAKMEM_TINY_COUNTERS_DUMP, HAKMEM_TINY_REFILL_DUMP
- HAKMEM_PTR_TRACE_DUMP, HAKMEM_PTR_TRACE_VERBOSE

Files modified (9 core files):
- core/tiny_debug_ring.c (ring trace/dump)
- core/box/mailbox_box.c (mailbox trace + slowdisc)
- core/tiny_refill.h (refill trace)
- core/hakmem_tiny_superslab.c (superslab debug)
- core/box/ss_allocation_box.c (allocation debug)
- core/tiny_superslab_free.inc.h (free debug)
- core/box/front_metrics_box.c (frontend metrics)
- core/hakmem_tiny_stats.c (stats dump)
- core/ptr_trace.h (pointer trace)

Bug fixes during implementation:
1. mailbox_box.c - Fixed variable scope (moved 'used' outside guard)
2. hakmem_tiny_stats.c - Fixed incomplete declarations (on1, on2)

Impact:
- Binary size: -85KB total
  - bench_random_mixed_hakmem: 319K → 305K (-14K, -4.4%)
  - larson_hakmem: 380K → 309K (-71K, -18.7%)
- Performance: No regression (16.9-17.9M ops/s maintained)
- Functional: All tests pass (Random Mixed + Larson)
- Behavior: DEBUG ENV vars correctly ignored in RELEASE builds

Testing:
- Build: Clean compilation (warnings only, pre-existing)
- 100K Random Mixed: 16.9-17.9M ops/s (PASS)
- 10K Larson: 25.9M ops/s (PASS)
- DEBUG ENV verification: Correctly ignored (PASS)

Result: 14 DEBUG ENV variables now have zero overhead in RELEASE builds.

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

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-27 03:41:07 +09:00

3.1 KiB
Raw Blame History

ENV Variable Cleanup Analysis - Executive Summary

Scope

  • Initial sweep: 221 unique ENV variables across the runtime (getenv()).
  • Current view: Core features Ultra/BG/HeapV2 are active and must be preserved (A/B gated only).
  • Docs-only cleanup: 21 documentation-only variables (zero getenv hits) are tracked separately in SAFE_TO_DELETE_ENV_VARS.md.

Key Findings

  • Active, keep: Ultra path (core/ultra/*), BG spill (hakmem_batch.c, hakmem_tiny_bg_spill.o), HeapV2/FrontV2 (core/front/tiny_heap_v2.h, tiny_alloc_fast.inc.h) are compiled in and runtime-gated. Removing their ENV toggles would break A/B rollback.
  • SFC is live: hakmem_tiny_sfc.o is built; HAKMEM_SFC_ENABLE/CAPACITY/REFILL_COUNT/DEBUG/STATS_DUMP/CASCADE_PCT all drive behavior. Debug getenv duplication remains the top low-risk cleanup.
  • Doc-only set: 21 proposal-only ENV names (adaptive presets, generic debug knobs, legacy build flags) have no getenv calls; safe to drop from docs with zero runtime impact.
  • Count drift: Including .inc helpers raises the current getenv surface to ~279 names; initial 221 figure is kept as the baseline for this project’s first pass.

Quick Wins (low risk, Box-friendly)

  • SFC_DEBUG dedup: Move the four HAKMEM_SFC_DEBUG getenv calls behind one init-time flag (hakmem_tiny_sfc.c as the boundary). Reduces hot-path getenvs by 3.
  • Doc hygiene: Remove the 21 docs-only names from docs/specs/ENV_VARS*.md to keep the supported surface visible and reversible.

Items to Keep as-is (cannot delete)

  • Ultra toggles: HAKMEM_TINY_ULTRA_*, HAKMEM_ULTRA_SLIM_STATS — gated experiments but compiled; keep for rollback.
  • BG system: HAKMEM_BATCH_BG, HAKMEM_L25_BG_DRAIN, HAKMEM_L25_BG_MS — enabled by default; removal would change behavior.
  • HeapV2/FrontV2: HAKMEM_TINY_HEAP_V2_*, HAKMEM_TINY_FRONT_V2/SLIM/DIRECT/METRICS/DUMP — active path for tiny frontend; keep.

最新アクション（このセッション）

  • HAKMEM_SFC_DEBUG を init 1回読みへ集約（ホットパス getenv を排除）。
  • リリースビルドで以下の DEBUG/TRACE/STATS 系 ENV を無効化（getenv しない）:
    • HAKMEM_TINY_TRACE_RING, HAKMEM_TINY_DUMP_RING_ATEXIT
    • HAKMEM_TINY_RF_TRACE, HAKMEM_TINY_MAILBOX_TRACE, HAKMEM_TINY_MAILBOX_TRACE_LIMIT, HAKMEM_TINY_MAILBOX_SLOWDISC(_PERIOD)
    • HAKMEM_SS_PREWARM_DEBUG, HAKMEM_SS_FREE_DEBUG
    • HAKMEM_TINY_FRONT_METRICS, HAKMEM_TINY_FRONT_DUMP
    • HAKMEM_TINY_COUNTERS_DUMP, HAKMEM_TINY_REFILL_DUMP
    • HAKMEM_PTR_TRACE_DUMP, HAKMEM_PTR_TRACE_VERBOSE

Next Steps

  1. 残る DEBUG/TRACE/STATS 系 ENV を同様にリリースビルドで無効化 or init 1回読みへ移動。
  2. 21個のドキュメント専用変数を docs/specs/ENV_VARS*.md から削除。
  3. Ultra/BG/HeapV2 は現役のため A/B ゲートを維持したまま、削除は別フェーズで判断。

See ENV_CLEANUP_PLAN.md for the full getenv map (file+line) and ENV_CONSOLIDATION_PLAN.md for the long-term policy reduction (149 → ~30).