On Fri, Mar 20, 2015 at 06:40:39PM +0000, Sai Gurrappadi wrote:
> On 02/04/2015 10:31 AM, Morten Rasmussen wrote:
> > +/*
> > + * sched_group_energy(): Returns absolute energy consumption of cpus
> > belonging
> > + * to the sched_group including shared resources shared only by members of
> > the
> > + * group. Iterates over all cpus in the hierarchy below the sched_group
> > starting
> > + * from the bottom working it's way up before going to the next cpu until
> > all
> > + * cpus are covered at all levels. The current implementation is likely to
> > + * gather the same usage statistics multiple times. This can probably be
> > done in
> > + * a faster but more complex way.
> > + */
> > +static unsigned int sched_group_energy(struct sched_group *sg_top)
> > +{
> > + struct sched_domain *sd;
> > + int cpu, total_energy = 0;
> > + struct cpumask visit_cpus;
> > + struct sched_group *sg;
> > +
> > + WARN_ON(!sg_top->sge);
> > +
> > + cpumask_copy(&visit_cpus, sched_group_cpus(sg_top));
> > +
> > + while (!cpumask_empty(&visit_cpus)) {
> > + struct sched_group *sg_shared_cap = NULL;
> > +
> > + cpu = cpumask_first(&visit_cpus);
> > +
> > + /*
> > + * Is the group utilization affected by cpus outside this
> > + * sched_group?
> > + */
> > + sd = highest_flag_domain(cpu, SD_SHARE_CAP_STATES);
> > + if (sd && sd->parent)
> > + sg_shared_cap = sd->parent->groups;
> > +
> > + for_each_domain(cpu, sd) {
> > + sg = sd->groups;
> > +
> > + /* Has this sched_domain already been visited? */
> > + if (sd->child && cpumask_first(sched_group_cpus(sg)) !=
> > cpu)
> > + break;
> > +
> > + do {
> > + struct sched_group *sg_cap_util;
> > + unsigned group_util;
> > + int sg_busy_energy, sg_idle_energy;
> > + int cap_idx;
> > +
> > + if (sg_shared_cap &&
> > sg_shared_cap->group_weight >= sg->group_weight)
> > + sg_cap_util = sg_shared_cap;
> > + else
> > + sg_cap_util = sg;
> > +
> > + cap_idx = find_new_capacity(sg_cap_util,
> > sg->sge);
> > + group_util = group_norm_usage(sg);
> > + sg_busy_energy = (group_util *
> > sg->sge->cap_states[cap_idx].power)
> > +
> > >> SCHED_CAPACITY_SHIFT;
> > + sg_idle_energy = ((SCHED_LOAD_SCALE-group_util)
> > * sg->sge->idle_states[0].power)
> > +
> > >> SCHED_CAPACITY_SHIFT;
> > +
> > + total_energy += sg_busy_energy + sg_idle_energy;
>
> Should normalize group_util with the newly found capacity instead of
> capacity_curr.
You're right. In the next patch when sched_group_energy() can be used
for energy predictions based on usage deltas group_util should be
normalized to the new capacity.
Thanks for spotting this mistake.
Morten
--
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/
