Re: [PATCH v3 5/6] sched/fair: Rename scale_load() and scale_load_down()

From: Peter Zijlstra
Date: Thu Apr 28 2016 - 05:19:42 EST


On Tue, Apr 05, 2016 at 12:12:30PM +0800, Yuyang Du wrote:
> Rename scale_load() and scale_load_down() to user_to_kernel_load()
> and kernel_to_user_load() respectively, to allow the names to bear
> what they are really about.

> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -189,7 +189,7 @@ static void __update_inv_weight(struct load_weight *lw)
> if (likely(lw->inv_weight))
> return;
>
> - w = scale_load_down(lw->weight);
> + w = kernel_to_user_load(lw->weight);
>
> if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
> lw->inv_weight = 1;
> @@ -213,7 +213,7 @@ static void __update_inv_weight(struct load_weight *lw)
> */
> static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight *lw)
> {
> - u64 fact = scale_load_down(weight);
> + u64 fact = kernel_to_user_load(weight);
> int shift = WMULT_SHIFT;
>
> __update_inv_weight(lw);
> @@ -6952,10 +6952,11 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
> */
> if (busiest->group_type == group_overloaded &&
> local->group_type == group_overloaded) {
> + unsigned long min_cpu_load =
> + kernel_to_user_load(NICE_0_LOAD) * busiest->group_capacity;
> load_above_capacity = busiest->sum_nr_running * NICE_0_LOAD;
> - if (load_above_capacity > scale_load(busiest->group_capacity))
> - load_above_capacity -=
> - scale_load(busiest->group_capacity);
> + if (load_above_capacity > min_cpu_load)
> + load_above_capacity -= min_cpu_load;
> else
> load_above_capacity = ~0UL;
> }

Except these 3 really are not about user/kernel visible fixed point
ranges _at_all_... :/