scooby_high_bw_thresh

[chaio001]

I’m running the released Pythia (Scooby) code and noticed a potential configuration issue around the “high bandwidth” state flag.

In the default config/pythia.ini, I don’t see a knob for scooby_high_bw_thresh (it’s not listed alongside the other Scooby knobs). However, in src/knobs.cc the default appears to be:

uint32_t scooby_high_bw_thresh = 4;

And Scooby::is_high_bw() is implemented as:

bool Scooby::is_high_bw()
{
    return bw_level >= knob::scooby_high_bw_thresh ? true : false;
}

In my experiments, state->is_high_bw seems to always be false. I’m concerned this could effectively disable the “high bandwidth” mode (and potentially limit Pythia’s ability to adapt to bandwidth pressure), especially since scooby_enable_hbw_reward is enabled by default.

Questions:

• Should scooby_high_bw_thresh be explicitly set in pythia.ini (or exposed there by default)?
• What is the expected range/meaning of bw_level in the released setup, and under what conditions should it reach values ≥ 4?
• If I should tune scooby_high_bw_thresh, is there a recommended value (or a guideline based on the bandwidth-level quantization / epoching)?

Any clarification on the intended default behavior would be very helpful. Thanks!