| Message ID | 1471639427-16006-1-git-send-email-smuckle@linaro.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Fri, Aug 19, 2016 at 01:43:47PM -0700, Steve Muckle wrote: > PELT does not consider SMT when scaling its utilization values via > arch_scale_cpu_capacity(). The value in rq->cpu_capacity_orig does > take SMT into consideration though and therefore may be smaller than > the utilization reported by PELT. > > On an Intel i7-3630QM for example rq->cpu_capacity_orig is 589 but > util_avg scales up to 1024. This means that a 50% utilized CPU will show > up in schedutil as ~86% busy. > > Fix this by using the same CPU scaling value in schedutil as that which > is used by PELT. > > Signed-off-by: Steve Muckle <smuckle@linaro.org> > --- > kernel/sched/cpufreq_schedutil.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index 60d985f4dc47..cb8a77b1ef1b 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -147,7 +147,9 @@ static unsigned int get_next_freq(struct sugov_cpu *sg_cpu, unsigned long util, > static void sugov_get_util(unsigned long *util, unsigned long *max) > { > struct rq *rq = this_rq(); > - unsigned long cfs_max = rq->cpu_capacity_orig; > + unsigned long cfs_max; > + > + cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); Until we have figured out how to define utilization (and capacity) better for SMT I think this is a better solution. Morten -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 60d985f4dc47..cb8a77b1ef1b 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -147,7 +147,9 @@ static unsigned int get_next_freq(struct sugov_cpu *sg_cpu, unsigned long util, static void sugov_get_util(unsigned long *util, unsigned long *max) { struct rq *rq = this_rq(); - unsigned long cfs_max = rq->cpu_capacity_orig; + unsigned long cfs_max; + + cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); *util = min(rq->cfs.avg.util_avg, cfs_max); *max = cfs_max;
PELT does not consider SMT when scaling its utilization values via arch_scale_cpu_capacity(). The value in rq->cpu_capacity_orig does take SMT into consideration though and therefore may be smaller than the utilization reported by PELT. On an Intel i7-3630QM for example rq->cpu_capacity_orig is 589 but util_avg scales up to 1024. This means that a 50% utilized CPU will show up in schedutil as ~86% busy. Fix this by using the same CPU scaling value in schedutil as that which is used by PELT. Signed-off-by: Steve Muckle <smuckle@linaro.org> --- kernel/sched/cpufreq_schedutil.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)