Phase 24-26: Hot path atomic telemetry prune (+2.00% cumulative)

Summary:
- Phase 24 (alloc stats): +0.93% GO
- Phase 25 (free stats): +1.07% GO
- Phase 26 (diagnostics): -0.33% NEUTRAL (code cleanliness)
- Total: 11 atomics compiled-out, +2.00% improvement

Phase 24: OBSERVE tax prune (tiny_class_stats_box.h)
- Added HAKMEM_TINY_CLASS_STATS_COMPILED (default: 0)
- Wrapped 5 stats functions: uc_miss, warm_hit, shared_lock, tls_carve_*
- Result: +0.93% (baseline 56.675M vs compiled-in 56.151M ops/s)

Phase 25: Tiny free stats prune (tiny_superslab_free.inc.h)
- Added HAKMEM_TINY_FREE_STATS_COMPILED (default: 0)
- Wrapped g_free_ss_enter atomic in free hot path
- Result: +1.07% (baseline 57.017M vs compiled-in 56.415M ops/s)

Phase 26: Hot path diagnostic atomics prune
- Added 5 compile gates for low-frequency error counters:
  - HAKMEM_TINY_C7_FREE_COUNT_COMPILED
  - HAKMEM_TINY_HDR_MISMATCH_LOG_COMPILED
  - HAKMEM_TINY_HDR_META_MISMATCH_COMPILED
  - HAKMEM_TINY_METRIC_BAD_CLASS_COMPILED
  - HAKMEM_TINY_HDR_META_FAST_COMPILED
- Result: -0.33% NEUTRAL (within noise, kept for cleanliness)

Alignment with mimalloc principles:
- "No atomics on hot path" - telemetry moved to compile-time opt-in
- Fixed per-op tax elimination
- Production builds: maximum performance (atomics compiled-out)
- Research builds: full diagnostics (COMPILED=1)

Generated with Claude Code
https://claude.com/claude-code

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scripts/audit_atomics.sh

@@ -0,0 +1,79 @@
+#!/bin/bash
+# audit_atomics.sh - Comprehensive atomic operation audit
+# Purpose: Find and classify all atomic operations in hot/warm/cold paths
+# Output: JSON-formatted audit report for Phase 26+ planning
+
+set -euo pipefail
+
+CORE_DIR="/mnt/workdisk/public_share/hakmem/core"
+OUTPUT_FILE="/mnt/workdisk/public_share/hakmem/docs/analysis/ATOMIC_AUDIT_FULL.txt"
+
+echo "=== HAKMEM Atomic Operations Audit ===" > "$OUTPUT_FILE"
+echo "Date: $(date)" >> "$OUTPUT_FILE"
+echo "Purpose: Identify telemetry-only atomics for compile-out (Phase 26+)" >> "$OUTPUT_FILE"
+echo "" >> "$OUTPUT_FILE"
+
+# Find all atomic_fetch_add/sub operations
+echo "## Part 1: atomic_fetch_add/sub operations" >> "$OUTPUT_FILE"
+echo "" >> "$OUTPUT_FILE"
+
+rg -n "atomic_fetch_(add|sub)_explicit\(" "$CORE_DIR/" --no-heading | \
+  while IFS=: read -r file line code; do
+    echo "FILE: $file" >> "$OUTPUT_FILE"
+    echo "LINE: $line" >> "$OUTPUT_FILE"
+    echo "CODE: $code" >> "$OUTPUT_FILE"
+
+    # Extract variable name
+    var=$(echo "$code" | grep -oP '&\K[a-zA-Z_][a-zA-Z0-9_]*(?=\s*,)' || echo "UNKNOWN")
+    echo "VAR: $var" >> "$OUTPUT_FILE"
+
+    # Classify based on variable naming patterns
+    if echo "$var" | grep -qE '(stats|count|trace|debug|diag|log|metric|observe|enter|exit|hit|miss|attempt|success)'; then
+      echo "CLASS: TELEMETRY (candidate for compile-out)" >> "$OUTPUT_FILE"
+    elif echo "$var" | grep -qE '(remote|refcount|owner|lock|head|tail|used|active|in_use)'; then
+      echo "CLASS: CORRECTNESS (do not touch)" >> "$OUTPUT_FILE"
+    else
+      echo "CLASS: UNKNOWN (manual review needed)" >> "$OUTPUT_FILE"
+    fi
+
+    # Determine path type based on file
+    if echo "$file" | grep -qE '(alloc_fast|free_fast|malloc_tiny_fast)'; then
+      echo "PATH: HOT (highest priority)" >> "$OUTPUT_FILE"
+    elif echo "$file" | grep -qE '(superslab_free|hakmem_tiny_free|tiny_alloc)'; then
+      echo "PATH: HOT (high priority)" >> "$OUTPUT_FILE"
+    elif echo "$file" | grep -qE '(refill|spill|magazine)'; then
+      echo "PATH: WARM (medium priority)" >> "$OUTPUT_FILE"
+    else
+      echo "PATH: COLD (low priority)" >> "$OUTPUT_FILE"
+    fi
+
+    echo "---" >> "$OUTPUT_FILE"
+  done
+
+echo "" >> "$OUTPUT_FILE"
+echo "## Part 2: Summary by Classification" >> "$OUTPUT_FILE"
+echo "" >> "$OUTPUT_FILE"
+
+# Count telemetry atomics
+TELEMETRY_COUNT=$(grep -c "CLASS: TELEMETRY" "$OUTPUT_FILE" || true)
+CORRECTNESS_COUNT=$(grep -c "CLASS: CORRECTNESS" "$OUTPUT_FILE" || true)
+UNKNOWN_COUNT=$(grep -c "CLASS: UNKNOWN" "$OUTPUT_FILE" || true)
+
+echo "Total TELEMETRY atomics: $TELEMETRY_COUNT" >> "$OUTPUT_FILE"
+echo "Total CORRECTNESS atomics: $CORRECTNESS_COUNT" >> "$OUTPUT_FILE"
+echo "Total UNKNOWN atomics: $UNKNOWN_COUNT" >> "$OUTPUT_FILE"
+echo "" >> "$OUTPUT_FILE"
+
+# Count by path
+HOT_COUNT=$(grep -c "PATH: HOT" "$OUTPUT_FILE" || true)
+WARM_COUNT=$(grep -c "PATH: WARM" "$OUTPUT_FILE" || true)
+COLD_COUNT=$(grep -c "PATH: COLD" "$OUTPUT_FILE" || true)
+
+echo "Hot path atomics: $HOT_COUNT" >> "$OUTPUT_FILE"
+echo "Warm path atomics: $WARM_COUNT" >> "$OUTPUT_FILE"
+echo "Cold path atomics: $COLD_COUNT" >> "$OUTPUT_FILE"
+
+echo "" >> "$OUTPUT_FILE"
+echo "Audit complete. Review $OUTPUT_FILE for details." >> "$OUTPUT_FILE"
+
+cat "$OUTPUT_FILE"