On 09/10/2014 07:20 PM, Peter Zijlstra wrote: > On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote: >>> - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { >>> - if (sched_feat(ARCH_CAPACITY)) >> >> Aren't you missing this check above? I understand that it is not >> crucial, but that would also mean removing ARCH_CAPACITY sched_feat >> altogether, wouldn't it? > > Yes he's missing that, I added the below bit on top. > > So the argument last time: > lkml.kernel.org/r/20140709105721.gt19...@twins.programming.kicks-ass.net > was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_* > function. The test has to be outside, seeing how it needs to decide to > call the arch function at all (or revert to the default implementation). > > --- > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5700,7 +5700,7 @@ unsigned long __weak arch_scale_freq_cap > return default_scale_capacity(sd, cpu); > } > > -unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int > cpu) > +static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int > cpu) > { > if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) > return sd->smt_gain / sd->span_weight; > @@ -5708,6 +5708,11 @@ unsigned long __weak arch_scale_cpu_capa > return SCHED_CAPACITY_SCALE; > } > > +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int > cpu) > +{ > + return default_scale_cpu_capacity(sd, cpu); > +} > + > static unsigned long scale_rt_capacity(int cpu) > { > struct rq *rq = cpu_rq(cpu); > @@ -5747,7 +5752,10 @@ static void update_cpu_capacity(struct s > unsigned long capacity = SCHED_CAPACITY_SCALE; > struct sched_group *sdg = sd->groups; > > - capacity *= arch_scale_cpu_capacity(sd, cpu); > + if (sched_feat(ARCH_CAPACITY)) > + capacity *= arch_scale_cpu_capacity(sd, cpu); > + else > + capacity *= default_scale_cpu_capacity(sd, cpu); > > capacity >>= SCHED_CAPACITY_SHIFT; > > Alright, I see now. Thanks!
Regards Preeti U Murthy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/