Re: [RFC PATCH v2 1/6] sched/fair: Create util_fits_capacity()

[Dietmar Eggemann]

On 04/12/2018 09:02 AM, Viresh Kumar wrote:
> On 06-04-18, 16:36, Dietmar Eggemann wrote:
> > The functionality that a given utilization fits into a given capacity
> > is factored out into a separate function.
> >
> > Currently it is only used in wake_cap() but will be re-used to figure
> > out if a cpu or a scheduler group is over-utilized.
> >
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Signed-off-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> > ---
> >   kernel/sched/fair.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index 0951d1c58d2f..0a76ad2ef022 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -6574,6 +6574,11 @@ static unsigned long cpu_util_wake(int cpu, struct task_struct *p)
> >   	return min_t(unsigned long, util, capacity_orig_of(cpu));
> >   }
> >   
> > +static inline int util_fits_capacity(unsigned long util, unsigned long capacity)
> > +{
> > +	return capacity * 1024 > util * capacity_margin;
>
> This changes the behavior slightly compared to existing code. If that
> wasn't intentional, perhaps you should use >= here.

You're right here ... Already on our v3 list. Thanks!

The 'misfit' patch-set comes with a similar function 
task_fits_capacity() so we have to align on this one with this patch-set 
as well.

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