diff options
Diffstat (limited to 'tools/power/cpupower/utils/idle_monitor/mperf_monitor.c')
| -rw-r--r-- | tools/power/cpupower/utils/idle_monitor/mperf_monitor.c | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c index 7cae74202a4d..afb2e6f8edd3 100644 --- a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c +++ b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c @@ -86,15 +86,35 @@ static int mperf_get_tsc(unsigned long long *tsc) return ret; } +static int get_aperf_mperf(int cpu, unsigned long long *aval, + unsigned long long *mval) +{ + int ret; + + /* + * Running on the cpu from which we read the registers will + * prevent APERF/MPERF from going out of sync because of IPI + * latency introduced by read_msr()s. + */ + if (mperf_monitor.flags.per_cpu_schedule) { + if (bind_cpu(cpu)) + return 1; + } + + ret = read_msr(cpu, MSR_APERF, aval); + ret |= read_msr(cpu, MSR_MPERF, mval); + + return ret; +} + static int mperf_init_stats(unsigned int cpu) { - unsigned long long val; + unsigned long long aval, mval; 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; + ret = get_aperf_mperf(cpu, &aval, &mval); + aperf_previous_count[cpu] = aval; + mperf_previous_count[cpu] = mval; is_valid[cpu] = !ret; return 0; @@ -102,13 +122,12 @@ static int mperf_init_stats(unsigned int cpu) static int mperf_measure_stats(unsigned int cpu) { - unsigned long long val; + unsigned long long aval, mval; 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; + ret = get_aperf_mperf(cpu, &aval, &mval); + aperf_current_count[cpu] = aval; + mperf_current_count[cpu] = mval; is_valid[cpu] = !ret; return 0; @@ -305,6 +324,9 @@ struct cpuidle_monitor *mperf_register(void) if (init_maxfreq_mode()) return NULL; + if (cpupower_cpu_info.vendor == X86_VENDOR_AMD) + mperf_monitor.flags.per_cpu_schedule = 1; + /* Free this at program termination */ is_valid = calloc(cpu_count, sizeof(int)); mperf_previous_count = calloc(cpu_count, sizeof(unsigned long long)); |