Re: [PATCH 04/17] sched/fair: Add avg_vruntime

From: Josh Don
Date: Tue Mar 28 2023 - 19:59:03 EST


On Tue, Mar 28, 2023 at 4:06 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
[...]
> +/*
> + * Compute virtual time from the per-task service numbers:
> + *
> + * Fair schedulers conserve lag: \Sum lag_i = 0
> + *
> + * lag_i = S - s_i = w_i * (V - v_i)
> + *
> + * \Sum lag_i = 0 -> \Sum w_i * (V - v_i) = V * \Sum w_i - \Sum w_i * v_i = 0

Small note: I think it would be helpful to label these symbols
somewhere :) Weight and vruntime are fairly obvious, but I don't
think 'S' and 'V' are as clear. Are these non-virtual ideal service
time, and average vruntime, respectively?