linux/tools/power
Chen Yu 8c69da2930 tools/power turbostat: Enable tsc_tweak for Elkhart Lake and Jasper Lake
It was found that on Elkhart Lake the TSC frequency is driven by
a separate crystal-clock domain, which is different from the
BCLK domain which includes mperf. This has result in small different
speed thus inconsistence between TSC and the mperf, which caused the
Busy% to be higher than 100%. On this platform it seems that the mperf
runs faster than tsc when the CPU is 100% utilized:
delta tsc(18815473183) < delta mperf(18958403680) for 10 seconds.

To align TSC with mperf, leverage the tsc_tweak mechanism introduced for
cores newer than Skylake, so that TSC and mperf would be calculated in
the same domain.

Reported-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2021-05-04 19:09:00 -04:00
..
acpi ACPICA: Updated all copyrights to 2021 2021-01-22 15:51:53 +01:00
cpupower cpupower: Add cpuid cap flag for MSR_AMD_HWCR support 2021-01-26 09:40:45 -07:00
pm-graph pm-graph v5.8 2020-11-23 18:20:28 +01:00
x86 tools/power turbostat: Enable tsc_tweak for Elkhart Lake and Jasper Lake 2021-05-04 19:09:00 -04:00