Constant IDLE_CHURN_PRECISE_TIMING 

pub const IDLE_CHURN_PRECISE_TIMING: bool = false;

Default for WorkType::IdleChurn’s precise_timing field. false keeps the inherited 50µs current->timer_slack_ns the variant doc describes; opt-in callers set the field to true directly to call prctl(PR_SET_TIMERSLACK, 1).