/*
* (C) 2010,2011 Thomas Renninger <trenn@suse.de>, Novell Inc.
*
* Licensed under the terms of the GNU GPL License version 2.
*/
#if defined(__i386__) || defined(__x86_64__)
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <cpufreq.h>
#include "helpers/helpers.h"
#include "idle_monitor/cpupower-monitor.h"
#define MSR_APERF 0xE8
#define MSR_MPERF 0xE7
#define MSR_TSC 0x10
enum mperf_id { C0 = 0, Cx, AVG_FREQ, MPERF_CSTATE_COUNT };
static int mperf_get_count_percent(unsigned int self_id, double *percent,
unsigned int cpu);
static int mperf_get_count_freq(unsigned int id, unsigned long long *count,
unsigned int cpu);
static cstate_t mperf_cstates[MPERF_CSTATE_COUNT] = {
{
.name = "C0",
.desc = N_("Processor Core not idle"),
.id = C0,
.range = RANGE_THREAD,
.get_count_percent = mperf_get_count_percent,
},
{
.name = "Cx",
.desc = N_("Processor Core in an idle state"),
.id = Cx,
.range = RANGE_THREAD,
.get_count_percent = mperf_get_count_percent,
},
{
.name = "Freq",
.desc = N_("Average Frequency (including boost) in MHz"),
.id = AVG_FREQ,
.range = RANGE_THREAD,
.get_count = mperf_get_count_freq,
},
};
static unsigned long long tsc_at_measure_start;
static unsigned long long tsc_at_measure_end;
static unsigned long max_frequency;
static unsigned long long *mperf_previous_count;
static unsigned long long *aperf_previous_count;
static unsigned long long *mperf_current_count;
static unsigned long long *aperf_current_count;
/* valid flag for all CPUs. If a MSR read failed it will be zero */
static int *is_valid;
static int mperf_get_tsc(unsigned long long *tsc)
{
return read_msr(0, MSR_TSC, tsc);
}
static int mperf_init_stats(unsigned int cpu)
{
unsigned long long val;
int ret;
ret = read_msr(cpu, MSR_APERF, &val);
aperf_previous_count[cpu] = val;
ret |= read_msr(cpu, MSR_MPERF, &val);
mperf_previous_count[cpu] = val;
is_valid[cpu] = !ret;
return 0;
}
static int mperf_measure_stats(unsigned int cpu)
{
unsigned long long val;
int ret;
ret = read_msr(cpu, MSR_APERF, &val);
aperf_current_count[cpu] = val;
ret |= read_msr(cpu, MSR_MPERF, &val);
mperf_current_count[cpu] = val;
is_valid[cpu] = !ret;
return 0;
}
/*
* get_average_perf()
*
* Returns the average performance (also considers boosted frequencies)
*
* Input:
* aperf_diff: Difference of the aperf register over a time period
* mperf_diff: Difference of the mperf register over the same time period
* max_freq: Maximum frequency (P0)
*
* Returns:
* Average performance over the time period
*/
static unsigned long get_average_perf(unsigned long long aperf_diff,
unsigned long long mperf_diff)
{
unsigned int perf_percent = 0;
if (((unsigned long)(-1) / 100) < aperf_diff) {
int shift_count = 7;
aperf_diff >>= shift_count;
mperf_diff >>= shift_count;
}
perf_percent = (aperf_diff * 100) / mperf_diff;
return (max_frequency * perf_percent) / 100;
}
static int mperf_get_count_percent(unsigned int id, double *percent,
unsigned int cpu)
{
unsigned long long aperf_diff, mperf_diff, tsc_diff;
if (!is_valid[cpu])
return -1;
if (id != C0 && id != Cx)
return -1;
mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu];
aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu];
tsc_diff = tsc_at_measure_end - tsc_at_measure_start;
*percent = 100.0 * mperf_diff / tsc_diff;
dprint("%s: mperf_diff: %llu, tsc_diff: %llu\n",
mperf_cstates[id].name, mperf_diff, tsc_diff);
if (id == Cx)
*percent = 100.0 - *percent;
dprint("%s: previous: %llu - current: %llu - (%u)\n", mperf_cstates[id].name,
mperf_diff, aperf_diff, cpu);
dprint("%s: %f\n", mperf_cstates[id].name, *percent);
return 0;
}
static int mperf_get_count_freq(unsigned int id, unsigned long long *count,
unsigned int cpu)
{
unsigned long long aperf_diff, mperf_diff;
if (id != AVG_FREQ)
return 1;
if (!is_valid[cpu])
return -1;
mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu];
aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu];
/* Return MHz for now, might want to return KHz if column width is more
generic */
*count = get_average_perf(aperf_diff, mperf_diff) / 1000;
dprint("%s: %llu\n", mperf_cstates[id].name, *count);
return 0;
}
static int mperf_start(void)
{
int cpu;
unsigned long long dbg;
mperf_get_tsc(&tsc_at_measure_start);
for (cpu = 0; cpu < cpu_count; cpu++)
mperf_init_stats(cpu);
mperf_get_tsc(&dbg);
dprint("TSC diff: %llu\n", dbg - tsc_at_measure_start);
return 0;
}
static int mperf_stop(void)
{
unsigned long long dbg;
int cpu;
mperf_get_tsc(&tsc_at_measure_end);
for (cpu = 0; cpu < cpu_count; cpu++)
mperf_measure_stats(cpu);
mperf_get_tsc(&dbg);
dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end);
return 0;
}
struct cpuidle_monitor mperf_monitor;
struct cpuidle_monitor* mperf_register(void) {
unsigned long min;
if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF))
return NULL;
/* Assume min/max all the same on all cores */
if (cpufreq_get_hardware_limits(0, &min, &max_frequency)) {
dprint("Cannot retrieve max freq from cpufreq kernel "
"subsystem\n");
return NULL;
}
/* Free this at program termination */
is_valid = calloc(cpu_count, sizeof (int));
mperf_previous_count = calloc (cpu_count,
sizeof(unsigned long long));
aperf_previous_count = calloc (cpu_count,
sizeof(unsigned long long));
mperf_current_count = calloc (cpu_count,
sizeof(unsigned long long));
aperf_current_count = calloc (cpu_count,
sizeof(unsigned long long));
mperf_monitor.name_len = strlen(mperf_monitor.name);
return &mperf_monitor;
}
void mperf_unregister(void) {
free(mperf_previous_count);
free(aperf_previous_count);
free(mperf_current_count);
free(aperf_current_count);
free(is_valid);
}
struct cpuidle_monitor mperf_monitor = {
.name = "Mperf",
.hw_states_num = MPERF_CSTATE_COUNT,
.hw_states = mperf_cstates,
.start = mperf_start,
.stop = mperf_stop,
.do_register = mperf_register,
.unregister = mperf_unregister,
.needs_root = 1,
.overflow_s = 922000000 /* 922337203 seconds TSC overflow
at 20GHz */
};
#endif /* #if defined(__i386__) || defined(__x86_64__) */
