tools/power turbostat: KNL workaround for %Busy and Avg_MHz
KNL increments APERF and MPERF every 1024 clocks.
This is compliant with the architecture specification,
which requires that only the ratio of APERF/MPERF need be valid.
However, turbostat takes advantage of the fact that these
two MSRs increment every un-halted clock
at the actual and base frequency:
AVG_MHz = APERF_delta/measurement_interval
%Busy = MPERF_delta/TSC_delta
This quirk is needed for these calculations to also work on KNL,
which would otherwise show a value 1024x smaller than expected.
Signed-off-by: Hubert Chrzaniuk <hubert.chrzaniuk@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index e05d3033..d333c81 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -71,6 +71,7 @@
unsigned int extra_msr_offset64;
unsigned int extra_delta_offset32;
unsigned int extra_delta_offset64;
+unsigned int aperf_mperf_multiplier = 1;
int do_smi;
double bclk;
unsigned int show_pkg;
@@ -984,6 +985,8 @@
return -3;
if (get_msr(cpu, MSR_IA32_MPERF, &t->mperf))
return -4;
+ t->aperf = t->aperf * aperf_mperf_multiplier;
+ t->mperf = t->mperf * aperf_mperf_multiplier;
}
if (do_smi) {
@@ -2541,6 +2544,13 @@
return 0;
}
+unsigned int get_aperf_mperf_multiplier(unsigned int family, unsigned int model)
+{
+ if (is_knl(family, model))
+ return 1024;
+ return 1;
+}
+
#define SLM_BCLK_FREQS 5
double slm_freq_table[SLM_BCLK_FREQS] = { 83.3, 100.0, 133.3, 116.7, 80.0};
@@ -2742,6 +2752,9 @@
}
}
+ if (has_aperf)
+ aperf_mperf_multiplier = get_aperf_mperf_multiplier(family, model);
+
do_nhm_platform_info = do_nhm_cstates = do_smi = probe_nhm_msrs(family, model);
do_snb_cstates = has_snb_msrs(family, model);
do_pc2 = do_snb_cstates && (pkg_cstate_limit >= PCL__2);