Re: [RFCv5 PATCH 40/46] sched/cpufreq_sched: compute freq_new based on capacity_orig_of()
From: Michael Turquette <mturquette@baylibre.com>
Date: 2015-07-08 15:22:48
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Quoting Morten Rasmussen (2015-07-07 11:24:23)
From: Juri Lelli <redacted> capacity is both cpu and freq scaled with EAS. We thus need to compute freq_new using capacity_orig_of(), so that we properly scale back the thing on heterogeneous architectures. In fact, capacity_orig_of() returns only the cpu scaled part of capacity (see update_cpu_capacity()). So, to scale freq_new correctly, we multiply policy->max by capacity/capacity_orig_of() instead of capacity/1024. cc: Ingo Molnar <mingo@redhat.com> cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Juri Lelli <redacted>
Looks good to me. Please feel free to add my Reviewed-by or Acked-by as appropriate. Regards, Mike
quoted hunk ↗ jump to hunk
--- kernel/sched/cpufreq_sched.c | 2 +- kernel/sched/fair.c | 2 +- kernel/sched/sched.h | 2 ++ 3 files changed, 4 insertions(+), 2 deletions(-)diff --git a/kernel/sched/cpufreq_sched.c b/kernel/sched/cpufreq_sched.c index 2968f3a..7071528 100644 --- a/kernel/sched/cpufreq_sched.c +++ b/kernel/sched/cpufreq_sched.c@@ -184,7 +184,7 @@ void cpufreq_sched_set_cap(int cpu, unsigned long capacity) goto out; /* Convert the new maximum capacity request into a cpu frequency */ - freq_new = capacity * policy->max >> SCHED_CAPACITY_SHIFT; + freq_new = (capacity * policy->max) / capacity_orig_of(cpu); /* No change in frequency? Bail and return current capacity. */ if (freq_new == policy->cur)diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d395bc9..f74e9d2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c@@ -4625,7 +4625,7 @@ static unsigned long capacity_of(int cpu) return cpu_rq(cpu)->cpu_capacity; } -static unsigned long capacity_orig_of(int cpu) +unsigned long capacity_orig_of(int cpu) { return cpu_rq(cpu)->cpu_capacity_orig; }diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b5e27d9..1327dc7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h@@ -1476,6 +1476,8 @@ unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) } #endif +unsigned long capacity_orig_of(int cpu); + extern struct static_key __sched_energy_freq; static inline bool sched_energy_freq(void) {-- 1.9.1 -- 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