Re: [PATCH V3 0/4] cpufreq: cppc: Add support for frequency invariance
From: Qian Cai <hidden>
Date: 2021-06-21 20:48:54
Also in:
linux-acpi, lkml
On 6/21/2021 5:19 AM, Viresh Kumar wrote:
CPPC cpufreq driver is used for ARM servers and this patch series tries to provide counter-based frequency invariance support for them in the absence for architecture specific counters (like AMUs).
Viresh, this series works fine on my quick tests so far. BTW, I noticed some strange things even with the series applied mentioned below when reading acpi_cppc vs cpufreq sysfs. Do you happen to know are those just hardware/firmware issues because Linux just faithfully exported the register values? == Arm64 server Foo == CPU max MHz: 3000.0000 CPU min MHz: 1000.0000 /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf 300 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq 1000 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_nonlinear_perf 200 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_perf 100 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq <--- should be 3000? 2800 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_perf <--- should be 300? 280 /sys/devices/system/cpu/cpu0/acpi_cppc/reference_perf 100 == Arm64 server Bar == CPU max MHz: 3000.0000 CPU min MHz: 375.0000 /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf <--- should be 3000? There is no cpufreq boost. 3300 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq <--- don't understand why 0. 0 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_nonlinear_perf 375 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_perf 375 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq <--- ditto 0 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_perf 3000 /sys/devices/system/cpu/cpu0/acpi_cppc/reference_perf 100