Le Thursday 28 Apr 2016 à 11:19:19 (+0200), Peter Zijlstra a écrit :
> 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_... :/
While trying to optimize the calcultaion of min_cpu_load, i have broken
evrything
it should be :
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0b6659d..3411eb7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6953,7 +6953,7 @@ 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;
+ busiest->group_capacity * NICE_0_LOAD /
SCHED_CAPACITY_SCALE;
load_above_capacity = busiest->sum_nr_running * NICE_0_LOAD;
if (load_above_capacity > min_cpu_load)
load_above_capacity -= min_cpu_load;
>
>
