LXR linux/arch/x86/kernel/cpu/sched.c

   1#include <linux/sched.h>
   2#include <linux/math64.h>
   3#include <linux/percpu.h>
   4#include <linux/irqflags.h>
   5
   6#include <asm/cpufeature.h>
   7#include <asm/processor.h>
   8
   9#ifdef CONFIG_SMP
  10
  11static DEFINE_PER_CPU(struct aperfmperf, old_perf_sched);
  12
  13static unsigned long scale_aperfmperf(void)
  14{
  15        struct aperfmperf val, *old = &__get_cpu_var(old_perf_sched);
  16        unsigned long ratio, flags;
  17
  18        local_irq_save(flags);
  19        get_aperfmperf(&val);
  20        local_irq_restore(flags);
  21
  22        ratio = calc_aperfmperf_ratio(old, &val);
  23        *old = val;
  24
  25        return ratio;
  26}
  27
  28unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
  29{
  30        /*
  31         * do aperf/mperf on the cpu level because it includes things
  32         * like turbo mode, which are relevant to full cores.
  33         */
  34        if (boot_cpu_has(X86_FEATURE_APERFMPERF))
  35                return scale_aperfmperf();
  36
  37        /*
  38         * maybe have something cpufreq here
  39         */
  40
  41        return default_scale_freq_power(sd, cpu);
  42}
  43
  44unsigned long arch_scale_smt_power(struct sched_domain *sd, int cpu)
  45{
  46        /*
  47         * aperf/mperf already includes the smt gain
  48         */
  49        if (boot_cpu_has(X86_FEATURE_APERFMPERF))
  50                return SCHED_LOAD_SCALE;
  51
  52        return default_scale_smt_power(sd, cpu);
  53}
  54
  55#endif
  56