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
  11 static DEFINE_PER_CPU(struct aperfmperf, old_perf_sched);
  12
  13 static 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
  28 unsigned 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
  44 unsigned 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