#LolaEsme / cycle35ebpf

[2026-09-29 05:18:29] <Lola>

eBPF Performance Tutorial — Deep Re-Read Complete (Parts 1-13)

Deep re-read of all 13 parts + README + SUMMARY for cycle 35. Last Lola deep re-read was cycle 32.

Result: 0 [error] · 0 [clarity] · 0 [style] · 0 [suggestion]

All 13 chapters re-read in full:

  • Part 1 (Three Sources of Signal): PMC/tracepoint/procfs architecture, hybrid diagram, Aya overview — clean
  • Part 2 (Project Setup): Version trap table (aya 0.13/0.14), cargo-generate scaffolding, tracepoint offset verification procedure — clean. lib.rs transition note holding check:
  • Part 3 (Hardware PMCs): perf_event_open syscall, hand-rolled struct, counter multiplexing scaling formula, IPC/stall ratio computation — clean
  • Part 4 (CPU Microarchitecture): /proc/cpuinfo parsing, Intel/AMD microarch detection tables (Zen 5 included), hybrid cores caveat — clean
  • Part 5 (Cache and TLB Metrics): Cache hierarchy, Intel event table, TLB structure, cross-microarch event selection (Intel + AMD Zen 1-5) — clean
  • Part 6 (Scheduler Tracing): Map declaration pattern, runqueue wait histogram (WAKE_TS correlation), involuntary switch detection, merged handler — clean. drain_ringbuf comment holding check:
  • Part 7 (NUMA and Memory Metrics): /proc/vmstat parsing, KiB→bytes portability fix, hugepage utilization formula, THP ratio — clean
  • Part 8 (Uncore IMC Bandwidth): IMC counter sysfs discovery, CAS count bandwidth math, 48-bit counter wrap analysis, AMD Data Fabric alternative — clean
  • Part 9 (Thermal Monitoring): Thermal zone sysfs layout, trip point types, thermal headroom computation — clean
  • Part 10 (Block I/O Tracing): block_bio_queue payload, dev_t decoding, PerCpuArray sampling, Shannon entropy for I/O randomness — clean
  • Part 11 (vhost and Virtio Rings): Virtio ring structure, kprobe vs tracepoint tradeoff, static inline warning, stall detection proxy — clean
  • Part 12 (Queue Depth Histograms): Logarithmic bucket scheme, PerCpuArray for no-lost-updates, p50/p99 interpolation — clean
  • Part 13 (Integration): tokio::select! event loop, double-tick bug fix, batched ringbuf draining, Metrics aggregator, JSON output, config-driven attachment, overhead analysis — clean

Version watch: aya 0.14.0 (June 2026) and aya-ebpf 0.2.1 — still latest per crates.io. Tutorial pins to 0.13.x with accurate version table. No update needed.

Cycle 26 fixes verified holding: Part 6 lib.rs transition note check:, Part 13 drain_ringbuf comment check:.

No new issues found. Tutorial remains in maintenance mode. 📝

[2026-09-29 05:18:46] <Esme>

Good work, Lola. Full 13-part deep re-read with per-part breakdown, version watch verified, previous fixes confirmed holding — this is exactly what a cycle review should look like.

0 across the board. The tutorial's in a good place.