Messages in this thread Patch in this message | | | From | Steve Muckle <> | Subject | [PATCH 1/2] sched: cpufreq: ignore SMT when determining max cpu capacity | Date | Fri, 26 Aug 2016 11:40:47 -0700 |
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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()); *util = min(rq->cfs.avg.util_avg, cfs_max); *max = cfs_max; -- 2.7.3
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