52386401b3
Major Features: - Debug counter infrastructure for Refill Stage tracking - Free Pipeline counters (ss_local, ss_remote, tls_sll) - Diagnostic counters for early return analysis - Unified larson.sh benchmark runner with profiles - Phase 6-3 regression analysis documentation Bug Fixes: - Fix SuperSlab disabled by default (HAKMEM_TINY_USE_SUPERSLAB) - Fix profile variable naming consistency - Add .gitignore patterns for large files Performance: - Phase 6-3: 4.79 M ops/s (has OOM risk) - With SuperSlab: 3.13 M ops/s (+19% improvement) This is a clean repository without large log files. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
117 lines
3.3 KiB
Markdown
117 lines
3.3 KiB
Markdown
# Ring Size Analysis: Document Index
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## Overview
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This directory contains a comprehensive ultra-deep analysis of why `POOL_TLS_RING_CAP` changes affect `mid_large_mt` and `random_mixed` benchmarks differently, and provides a solution that improves BOTH.
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## Documents
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### 1. RING_SIZE_SUMMARY.md (Start Here!)
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**Length:** 2.4 KB
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**Read Time:** 2 minutes
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Executive summary with:
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- Problem statement
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- Root cause explanation
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- Solution overview
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- Expected results
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- Key insights
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**Best for:** Quick understanding of the issue and solution.
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### 2. RING_SIZE_VISUALIZATION.txt
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**Length:** 14 KB
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**Read Time:** 5 minutes
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Visual guide with ASCII art showing:
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- Pool routing diagrams
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- TLS memory footprint comparison
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- L1 cache pressure visualization
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- Performance bar charts
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- Implementation roadmap
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**Best for:** Visual learners who want to see the problem graphically.
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### 3. RING_SIZE_SOLUTION.md
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**Length:** 7.6 KB
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**Read Time:** 10 minutes
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Step-by-step implementation guide with:
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- Exact code changes (line numbers)
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- sed commands for bulk replacement
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- Testing plan with scripts
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- Expected performance matrix
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- Rollback plan
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**Best for:** Implementing the fix.
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### 4. RING_SIZE_DEEP_ANALYSIS.md
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**Length:** 18 KB
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**Read Time:** 30 minutes
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Complete technical analysis with 10 sections:
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1. Pool routing confirmation
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2. TLS memory footprint analysis
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3. Why ring size affects benchmarks differently
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4. Why Ring=128 hurts BOTH benchmarks
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5. Separate ring sizes per pool (solution)
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6. Optimal ring size sweep
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7. Other bottlenecks analysis
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8. Implementation guidance
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9. Recommended approach
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10. Conclusion + Appendix (cache analysis)
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**Best for:** Deep understanding of the root cause and trade-offs.
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## Quick Navigation
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**Want to:** → **Read:**
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- Understand the problem in 2 min → `RING_SIZE_SUMMARY.md`
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- See visual diagrams → `RING_SIZE_VISUALIZATION.txt`
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- Implement the fix → `RING_SIZE_SOLUTION.md`
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- Deep technical dive → `RING_SIZE_DEEP_ANALYSIS.md`
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## Key Findings
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### Root Cause
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`POOL_TLS_RING_CAP` controls ring size for L2 Pool (8-32KB) only:
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- **mid_large_mt** uses L2 Pool → benefits from larger rings
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- **random_mixed** uses Tiny Pool → hurt by L2's TLS growth evicting L1 cache
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### Solution
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Use separate ring sizes per pool:
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- L2 Pool: `POOL_L2_RING_CAP=48` (balanced)
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- L2.5 Pool: `POOL_L25_RING_CAP=16` (unchanged)
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- Tiny Pool: No ring (freelist-based, unchanged)
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### Expected Results
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| Metric | Ring=16 | Ring=64 | **L2=48** | vs Ring=64 |
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|--------|---------|---------|-----------|------------|
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| mid_large_mt | 36.04M | 37.22M | **36.8M** | -1.1% |
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| random_mixed | 22.5M | 21.29M | **22.5M** | **+5.7%** |
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| Average | 29.27M | 29.26M | **29.65M** | **+1.3%** |
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| TLS/thread | 2.36 KB | 5.05 KB | **3.4 KB** | **-33%** |
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**Win-Win:** Improves BOTH benchmarks simultaneously.
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## Implementation Timeline
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- Code changes: 30 minutes
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- Testing: 2-3 hours
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- Documentation: 30 minutes
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- **Total: ~4 hours**
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## Files to Modify
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1. `core/hakmem_pool.c` - Replace `POOL_TLS_RING_CAP` → `POOL_L2_RING_CAP`
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2. `core/hakmem_l25_pool.c` - Replace `POOL_TLS_RING_CAP` → `POOL_L25_RING_CAP`
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3. `Makefile` - Add `-DPOOL_L2_RING_CAP=48 -DPOOL_L25_RING_CAP=16`
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## Success Criteria
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✓ mid_large_mt: ≥36.5M ops/s (+1.3% vs baseline)
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✓ random_mixed: ≥22.4M ops/s (within ±1% of baseline)
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✓ TLS footprint: ≤3.5 KB/thread
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✓ No regressions in full benchmark suite
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