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Day25 - Hybrid Robustness and Update Coalescing

Objective

Validate:

  • Cooldown effectiveness
  • Event vs update ratio
  • Hybrid behavior under load

Setup

Example path:

/sys/class/hwmon/hwmonX/

Test Script

Use:

./stress_test.sh /sys/class/hwmon/hwmonX

Test Cases

Test 1: IRQ only

Expected:

  • irq_event_count >> irq_update_count
  • irq_skip_count increases

Test 2: Poll only

Expected:

  • poll_event_count ≈ poll_update_count
  • Few skips

Test 3: Hybrid

Expected:

  • IRQ generates many events
  • Polling provides stable updates
  • last_source may switch between irq and poll

Test 4: Cooldown stress

Configuration:

poll_interval_ms = small
min_update_interval_ms = large

Expected:

  • event_count >> update_count
  • skip_count increases significantly

Verification Checklist

  • No kernel crash
  • No deadlock
  • Counters behave consistently
  • Cooldown suppresses excessive updates

Analysis Tips

Look for:

update_ratio = update_count / event_count
  • Low ratio → strong coalescing
  • High ratio → frequent updates

Conclusion

A successful test shows:

  • Reduced redundant updates
  • Stable hybrid behavior
  • Clear separation of event/update/skip