[LTP] [PATCH v2] high_freq_hwp_cap_cppc.c: new test

[Petr Vorel]

> Verify for all online logical CPUs that their highest performance value are
> the same for HWP Capability MSR 0x771 and CPPC sysfs file.

> Signed-off-by: Piotr Kubaj <piotr.kubaj@intel.com>
> ---
>  testcases/kernel/power_management/.gitignore  |  1 +
>  .../power_management/high_freq_hwp_cap_cppc.c | 66 +++++++++++++++++++

As I wrote in v1, any tests needs to be added into runtest file,
runtest/power_management_tests in this case.

>  2 files changed, 67 insertions(+)
>  create mode 100644 testcases/kernel/power_management/high_freq_hwp_cap_cppc.c

...
> +static void run(void)
> +{
> +	bool status = true;
> +
> +	for (int i = 0; i < nproc; i++) {
> +		char path[PATH_MAX];
> +		unsigned long long msr_highest_perf = 0, sysfs_highest_perf = 0;
> +
> +		snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu%d/acpi_cppc/highest_perf", i);
> +		SAFE_FILE_SCANF(path, "%llu", &sysfs_highest_perf);
> +		tst_res(TDEBUG, "%s: %llu", path, sysfs_highest_perf);
> +
> +		snprintf(path, sizeof(path), "/dev/cpu/%d/msr", i);
> +		int fd = SAFE_OPEN(path, O_RDONLY);
> +
> +		if (SAFE_PREAD(1, fd, &msr_highest_perf, sizeof(msr_highest_perf), 0x771) == -1)
> +			tst_brk(TBROK | TERRNO, "MSR read error");

SAFE_*() functions contain error check, tst_brk() is redundant.

> +		msr_highest_perf &= (1ULL << 8) - 1;
> +		tst_res(TDEBUG, "%s: %llu", path, msr_highest_perf);
> +
> +		if (msr_highest_perf != sysfs_highest_perf)
> +			status = false;
> +	}
> +
> +	if (status)
> +		tst_res(TPASS, "Sysfs and MSR values are equal");
> +	else
> +		tst_res(TFAIL, "Highest performance values differ between sysfs and MSR");
I would print TFAIL in the for loop with CPU ID and both values.
And here print only final TPASS.

> +}
> +
> +static struct tst_test test = {
> +	.needs_kconfigs = (const char *const []) {
> +		"CONFIG_ACPI_CPPC_LIB",
> +		"CONFIG_X86_MSR",

Also even on this version I have:
high_freq_hwp_cap_cppc.c:31: TBROK: Failed to open FILE '/sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf' for reading: ENOENT (2)

on 6.18 kernel even I run modprobe msr

$ grep -e CONFIG_X86_MSR -e CONFIG_ACPI_CPPC_LIB /boot/config-6.18.*
CONFIG_X86_MSR=m
CONFIG_ACPI_CPPC_LIB=y

OTOH on 7.0.0-rc2 with the same config values autoloading worked.

Kind regards,
Petr