tools/power turbostat: Enable tsc_tweak for Elkhart Lake and Jasper Lake
authorChen Yu <yu.c.chen@intel.com>
Wed, 28 Apr 2021 02:51:57 +0000 (10:51 +0800)
committerLen Brown <len.brown@intel.com>
Tue, 4 May 2021 23:09:00 +0000 (19:09 -0400)
commit8c69da293041352d15a2b6e8010c141822a416c5
tree706505f8c5f4ff450297073735073966161b660e
parent1e3ec5cdfb63bc2a1ff06145faa2be08d6ec9594
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>
tools/power/x86/turbostat/turbostat.c