linux/tools/power
He Rongguang 97294d480d cpupower: fix TSC MHz calculation
[ Upstream commit 9d6c0e5851 ]

Commit 'cpupower: Make TSC read per CPU for Mperf monitor' (c2adb1877b)
changes TSC counter reads per cpu, but left time diff global (from start
of all cpus to end of all cpus), thus diff(time) is too large for a
cpu's tsc counting, resulting in far less than acutal TSC_Mhz and thus
`cpupower monitor` showing far less than actual cpu realtime frequency.

/proc/cpuinfo shows frequency:
cat /proc/cpuinfo | egrep -e 'processor' -e 'MHz'
...
processor : 171
cpu MHz   : 4108.498
...

before fix (System 100% busy):
    | Mperf              || Idle_Stats
 CPU| C0   | Cx   | Freq  || POLL | C1   | C2
 171|  0.77| 99.23|  2279||  0.00|  0.00|  0.00

after fix (System 100% busy):
    | Mperf              || Idle_Stats
 CPU| C0   | Cx   | Freq  || POLL | C1   | C2
 171|  0.46| 99.54|  4095||  0.00|  0.00|  0.00

Fixes: c2adb1877b ("cpupower: Make TSC read per CPU for Mperf monitor")
Signed-off-by: He Rongguang <herongguang@linux.alibaba.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-02-08 09:51:52 +01:00
..
acpi ACPICA: Update all copyrights/signons to 2023 2023-04-06 20:29:11 +02:00
cpupower cpupower: fix TSC MHz calculation 2025-02-08 09:51:52 +01:00
pm-graph PM: tools: Fix sleepgraph syntax error 2023-12-03 07:33:04 +01:00
x86 tools/power turbostat: Remember global max_die_id 2024-07-11 12:49:10 +02:00