Hi Vincent, On 03/28/2014 06:52 PM, Vincent Guittot wrote: > cpu_power_orig is only changed for SMT system in order to reflect the lower > capacity of CPUs. Heterogenous system also have to reflect an original > capacity that is different from the default value.
There is no parameter 'cpu_power_orig' till your fourth patch right? Why is this term being used in this patch? Besides, both parameters power and power_orig are changed for SMT systems to reflect the lower capacity of the CPUs.Why is there a mention of only power_orig? IMO, the subject of the patch is not clearly reflecting the main intention of the patch. There is nothing done to change the way cpu_power is used; rather you are changing the way the cpu_power is being set to be flexible, thus allowing for the right power value to be set on heterogeneous systems. 'Allow archs to set the cpu_power instead of falling to default value' or something similar would be more appropriate. What do you think? Regards Preeti U Murthy > > Create a more generic function arch_scale_cpu_power that can be also used by > non SMT platform to set cpu_power_orig. > > The weak behavior of arch_scale_cpu_power is the previous SMT one in order to > keep backward compatibility in the use of cpu_power_orig. > > Signed-off-by: Vincent Guittot <[email protected]> > --- > kernel/sched/fair.c | 24 ++++++++++++++++-------- > 1 file changed, 16 insertions(+), 8 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 7e9bd0b..ed42061 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5559,6 +5559,20 @@ unsigned long __weak arch_scale_smt_power(struct > sched_domain *sd, int cpu) > return default_scale_smt_power(sd, cpu); > } > > +unsigned long __weak arch_scale_cpu_power(struct sched_domain *sd, int cpu) > +{ > + unsigned long weight = sd->span_weight; > + > + if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { > + if (sched_feat(ARCH_POWER)) > + return arch_scale_smt_power(sd, cpu); > + else > + return default_scale_smt_power(sd, cpu); > + } > + > + return SCHED_POWER_SCALE; > +} > + > static unsigned long scale_rt_power(int cpu) > { > struct rq *rq = cpu_rq(cpu); > @@ -5590,18 +5604,12 @@ static unsigned long scale_rt_power(int cpu) > > static void update_cpu_power(struct sched_domain *sd, int cpu) > { > - unsigned long weight = sd->span_weight; > unsigned long power = SCHED_POWER_SCALE; > struct sched_group *sdg = sd->groups; > > - if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { > - if (sched_feat(ARCH_POWER)) > - power *= arch_scale_smt_power(sd, cpu); > - else > - power *= default_scale_smt_power(sd, cpu); > + power *= arch_scale_cpu_power(sd, cpu); > > - power >>= SCHED_POWER_SHIFT; > - } > + power >>= SCHED_POWER_SHIFT; > > sdg->sgp->power_orig = power; > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
