Function node

crates/kernel/src/shard.rs:2412–2414

(l: AggNode, r: AggNode)

/// system RAM by default).
pub const RAM_USABLE_FRAC: f64 = 0.85;

/// Predicted peak prover RAM (GiB) for a leaf of `cost` **actual** guest cost
/// units (for predicted cost, multiply by [`COST_MODEL_HEADROOM`] first to
/// get the worst-case bound the cap enforces).
pub fn ram_gib_for_steps(cost: u64) -> f64 {
  RAM_BASE_GIB + RAM_GIB_PER_BCOST * (cost as f64 / 1e9)