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

[Andrea Cervesato via ltp <ltp@lists.linux.it>]

Hi!

> Verify for all online logical CPUs that their highest performance value are
> the same for HWP Capability MSR 0x771 and CPPC sysfs file.
> ---
>  testcases/kernel/power_management/.gitignore  |  1 +
>  .../power_management/high_freq_hwp_cap_cppc.c | 57 +++++++++++++++++++
>  2 files changed, 58 insertions(+)
>  create mode 100644 testcases/kernel/power_management/high_freq_hwp_cap_cppc.c
> 
> diff --git a/testcases/kernel/power_management/.gitignore b/testcases/kernel/power_management/.gitignore
> index 0c2a3ed4b..c13bca1c4 100644
> --- a/testcases/kernel/power_management/.gitignore
> +++ b/testcases/kernel/power_management/.gitignore
> @@ -1 +1,2 @@
> +high_freq_hwp_cap_cppc
>  pm_get_sched_values
> diff --git a/testcases/kernel/power_management/high_freq_hwp_cap_cppc.c b/testcases/kernel/power_management/high_freq_hwp_cap_cppc.c
> new file mode 100644
> index 000000000..4cbb81f0b
> --- /dev/null
> +++ b/testcases/kernel/power_management/high_freq_hwp_cap_cppc.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +/*
> + * Copyright (C) 2025-2026 Intel - http://www.intel.com/
> + */

Remove space
> +
> +/*\
> + * Verify for all online logical CPUs  that their highest performance value are

Double space before "that"

> + * the same for HWP Capability MSR 0x771 and CPPC sysfs file.
> + */
> +
> +#include "tst_test.h"
> +
> +static int nproc;
> +
> +static void setup(void)
> +{
> +	nproc = tst_ncpus();
> +}
> +
> +static void run(void)
> +{
> +	for (int i = 0; i < nproc; i++) {
> +		char path[PATH_MAX];
> +		unsigned long long msr_highest_perf = 0, sysfs_highest_perf = 0;
> +
> +		snprintf(path, PATH_MAX, "/sys/devices/system/cpu/cpu%d/acpi_cppc/highest_perf", i);

snprintf(path, sizeof(path), ..) is better.

> +		SAFE_FILE_SCANF(path, "%llu", &sysfs_highest_perf);
> +		tst_res(TDEBUG, "%s: %llu", path, sysfs_highest_perf);
> +
> +		snprintf(path, PATH_MAX, "/dev/cpu/%d/msr", i);
> +		int fd = SAFE_OPEN(path, O_RDONLY);
> +
> +		if (pread(fd, &msr_highest_perf, sizeof(msr_highest_perf), 0x771) < 0) {
> +			SAFE_CLOSE(fd);
> +			tst_brk(TBROK | TERRNO, "MSR read error");
> +		}

Simply use SAFE_PREAD(). fd will be closed when test ends.

> +		SAFE_CLOSE(fd);
> +		msr_highest_perf &= (1ULL << 8) - 1;
> +		tst_res(TDEBUG, "%s: %llu", path, msr_highest_perf);
> +
> +		if (msr_highest_perf != sysfs_highest_perf)
> +			tst_brk(TFAIL, "CPU %d: highest performance values differ between sysfs and MSR", i);

Why tst_brk() ? It's supposed to be tst_res(TFAIL, ..).

> +	}
> +
> +	tst_res(TPASS, "Test pass");
> +}
> +
> +static struct tst_test test = {
> +	.needs_kconfigs = (const char *const []) {
> +		"CONFIG_X86_MSR",

The CPPC sysfs interface also requires CONFIG_ACPI_CPPC_LIB to be built.

> +		NULL
> +	},
> +	.needs_root = 1,
> +	.setup = setup,
> +	.test_all = run
> +};
> -- 
> 2.47.3
> 
> ---------------------------------------------------------------------
> Intel Technology Poland sp. z o.o.
> ul. Slowackiego 173 | 80-298 Gdansk | Sad Rejonowy Gdansk Polnoc | VII Wydzial Gospodarczy Krajowego Rejestru Sadowego - KRS 101882 | NIP 957-07-52-316 | Kapital zakladowy 200.000 PLN.
> Spolka oswiadcza, ze posiada status duzego przedsiebiorcy w rozumieniu ustawy z dnia 8 marca 2013 r. o przeciwdzialaniu nadmiernym opoznieniom w transakcjach handlowych.
> 
> Ta wiadomosc wraz z zalacznikami jest przeznaczona dla okreslonego adresata i moze zawierac informacje poufne. W razie przypadkowego otrzymania tej wiadomosci, prosimy o powiadomienie nadawcy oraz trwale jej usuniecie; jakiekolwiek przegladanie lub rozpowszechnianie jest zabronione.
> This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

There's also no runtest entry for this test, so it can't be run in the testing
suites by kirk.

Kind regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp