[igt-dev] [PATCH i-g-t 1/2] i915/i915_power: Sanity check power measurement

[Kamil Konieczny]

Hi Ashutosh,

On 2023-01-26 at 22:25:01 -0800, Ashutosh Dixit wrote:
> Add a test to sanity check power measurement on integrated/discrete by
> requiring power under load to be > 0 and >= idle power.
> 
> v2: Code reorganization (Kamil K)
> 
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
> Reviewed-by: Riana Tauro <riana.tauro at intel.com>
> ---
>  tests/i915/i915_power.c | 80 +++++++++++++++++++++++++++++++++++++++++
>  tests/meson.build       |  1 +
>  2 files changed, 81 insertions(+)
>  create mode 100644 tests/i915/i915_power.c
> 
> diff --git a/tests/i915/i915_power.c b/tests/i915/i915_power.c
> new file mode 100644
> index 00000000000..00993cdc846
> --- /dev/null
> +++ b/tests/i915/i915_power.c
> @@ -0,0 +1,80 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +
> +#include "igt.h"
> +#include "i915/gem.h"
> +#include "igt_power.h"
> +
> +IGT_TEST_DESCRIPTION("i915 power measurement tests");
> +
> +static double get_power(struct igt_power *pwr, const char *domain)
------------------------------------------------------------- ^
You are not using this so delete it.

> +{
> +	const int sleep_duration_sec = 2;
----------------- ^
Make this a parameter for function.

> +	struct power_sample sample[2];
> +
> +	igt_power_get_energy(pwr, &sample[0]);
> +	usleep(sleep_duration_sec * USEC_PER_SEC);
> +	igt_power_get_energy(pwr, &sample[1]);
> +
> +	return igt_power_get_mW(pwr, &sample[0], &sample[1]);
> +}
> +
> +static double measure_power(int i915, struct igt_power *pwr,
> +			    const char *domain, bool load)
----------------------------------------------- ^
This is confusing, delete this. Please avoid creating functions
with boolean parameter, just do its work in place you will use
true or false.

> +{
> +	const intel_ctx_t *ctx = intel_ctx_create_all_physical(i915);
> +	uint64_t ahnd = get_reloc_ahnd(i915, ctx->id);
> +	igt_spin_t *spin;
> +	double mW;
> +
> +	gem_quiescent_gpu(i915);
> +	if (load) {
------- ^
Delete this if() and move spin creation after idle see below.

> +		spin = igt_spin_new(i915, .ahnd = ahnd, .ctx = ctx,
> +				    .engine = ALL_ENGINES,
> +				    .flags = IGT_SPIN_POLL_RUN);
> +		/* Wait till at least one spinner starts */
> +		igt_spin_busywait_until_started(spin);
> +	}
> +
> +	mW = get_power(pwr, domain);
> +	igt_info("Domain: %s, Load: %d, Measured power: %g mW\n", domain, load, mW);
> +
> +	igt_free_spins(i915);
> +	put_ahnd(ahnd);
> +	intel_ctx_destroy(i915, ctx);
> +
> +	return mW;
> +}
> +
> +static void sanity(int i915, const char *domain)
> +{
> +	struct igt_power pwr;
> +	double idle, busy;
> +
> +	igt_require(!igt_power_open(i915, &pwr, domain));
> +	idle = measure_power(i915, &pwr, domain, false);
> +	busy = measure_power(i915, &pwr, domain, true);
> +	igt_power_close(&pwr);
> +
> +	igt_assert(idle >= 0 && busy > 0 && busy >= idle);
------------------------------------------------ ^
imho this should be "busy > idle" ?

Merge sanity() with measure_power() so it will be simple.
This should look like:
	// check require
	// prepare ctx and other
	idle = get_power(pwr, 2 * USEC_PER_SEC); /* 2 seconds */
	// create spin and wait until it will run
	busy = get_power(pwr, 2 * USEC_PER_SEC); /* 2 seconds */
	// cleanup after spin, ctx, and other
	// print info what was measured, domain, power and time used
	// assert

> +}
> +
> +igt_main
> +{
> +	int i915;
> +
> +	igt_fixture {
> +		i915 = drm_open_driver_master(DRIVER_INTEL);
> +	}
> +
> +	igt_describe("Sanity check power measurement");
> +	igt_subtest("sanity") {
> +		sanity(i915, "gpu");
----------------------------- ^
Do you plan other domains, maybe multi-gpu like gpu-#number ?

Regards,
Kamil

> +	}
> +
> +	igt_fixture {
> +		close(i915);
> +	}
> +}
> diff --git a/tests/meson.build b/tests/meson.build
> index cce9d89e1c8..d93a07c9ed6 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -213,6 +213,7 @@ i915_progs = [
>  	'i915_pm_dc',
>  	'i915_pm_rps',
>  	'i915_pm_sseu',
> +	'i915_power',
>  	'i915_query',
>  	'i915_selftest',
>  	'i915_suspend',
> -- 
> 2.38.0
>