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intel_pstate: Take core C0 time into account for core busy calculation 

Take non-idle time into account when calculating core busy time.
This ensures that intel_pstate will notice a decrease in load.

References: https://bugzilla.kernel.org/show_bug.cgi?id=66581
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dirk Brandewie 2014-02-03 08:55:31 -08:00 committed by Rafael J. Wysocki
parent 38dbfb59d1
commit fcb6a15c2e
1 changed files with 17 additions and 4 deletions
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21
drivers/cpufreq/intel_pstate.c
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@ -57,6 +57,7 @@ struct sample {
int32_t core_pct_busy;
u64 aperf;
u64 mperf;
unsigned long long tsc;
int freq;
};
@ -96,6 +97,7 @@ struct cpudata {
u64 prev_aperf;
u64 prev_mperf;
unsigned long long prev_tsc;
int sample_ptr;
struct sample samples[SAMPLE_COUNT];
};
@ -548,30 +550,41 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu,
struct sample *sample)
{
u64 core_pct;
core_pct = div64_u64(int_tofp(sample->aperf * 100),
sample->mperf);
sample->freq = fp_toint(cpu->pstate.max_pstate * core_pct * 1000);
u64 c0_pct;
sample->core_pct_busy = core_pct;
core_pct = div64_u64(sample->aperf * 100, sample->mperf);
c0_pct = div64_u64(sample->mperf * 100, sample->tsc);
sample->freq = fp_toint(
mul_fp(int_tofp(cpu->pstate.max_pstate),
int_tofp(core_pct * 1000)));
sample->core_pct_busy = mul_fp(int_tofp(core_pct),
div_fp(int_tofp(c0_pct + 1), int_tofp(100)));
}
static inline void intel_pstate_sample(struct cpudata *cpu)
{
u64 aperf, mperf;
unsigned long long tsc;
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);
tsc = native_read_tsc();
cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
cpu->samples[cpu->sample_ptr].aperf = aperf;
cpu->samples[cpu->sample_ptr].mperf = mperf;
cpu->samples[cpu->sample_ptr].tsc = tsc;
cpu->samples[cpu->sample_ptr].aperf -= cpu->prev_aperf;
cpu->samples[cpu->sample_ptr].mperf -= cpu->prev_mperf;
cpu->samples[cpu->sample_ptr].tsc -= cpu->prev_tsc;
intel_pstate_calc_busy(cpu, &cpu->samples[cpu->sample_ptr]);
cpu->prev_aperf = aperf;
cpu->prev_mperf = mperf;
cpu->prev_tsc = tsc;
}
static inline void intel_pstate_set_sample_time(struct cpudata *cpu)