[igt-dev] [PATCH i-g-t 1/2] tests/intel/xe_guc_pc: Add freq_power test

[Kamil Konieczny]

Hi,

On 2023-09-18 at 09:31:02 -0700, Belgaumkar, Vinay wrote:
> 
> On 9/6/2023 11:06 PM, Riana Tauro wrote:
> > An assumption is that at lower frequencies,
> > not only do we run slower, but we save power compared to
> > higher frequencies.
> > 
> > This test runs a spinner and sets the min and max frequencies
> > to rp0 and rpn respectively. It then checks if power measured
> > at lower frequencies is lesser.
> > 
> > Signed-off-by: Riana Tauro <riana.tauro at intel.com>
> > ---
> >   tests/intel/xe_guc_pc.c | 88 +++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 88 insertions(+)
> > 
> > diff --git a/tests/intel/xe_guc_pc.c b/tests/intel/xe_guc_pc.c
> > index 032816921..cea7b56fd 100644
> > --- a/tests/intel/xe_guc_pc.c
> > +++ b/tests/intel/xe_guc_pc.c
> > @@ -13,6 +13,7 @@
> >   #include "igt.h"
> >   #include "lib/igt_syncobj.h"
> > +#include "igt_power.h"
> >   #include "igt_sysfs.h"
> >   #include "xe_drm.h"
> > @@ -387,6 +388,82 @@ static void test_reset(int fd, int gt_id, int cycles)
> >   	}
> >   }
> > +static int cmp_u64(const void *a, const void *b)
> > +{
> > +	return (*(u64 *)a - *(u64 *)b);
> > +}
> > +
> > +static uint64_t measure_power(int fd, struct igt_power *gpu)
> > +{
> > +	struct power_sample sample[2];
> > +	uint64_t power[5];
> > +
> > +	for (int i = 0; i < 5; i++) {
> > +		igt_power_get_energy(gpu, &sample[0]);
> > +		usleep(10000); /* 10 ms */
> > +		igt_power_get_energy(gpu, &sample[1]);
> > +
> > +		power[i] = igt_power_get_mW(gpu, &sample[0], &sample[1]);
> > +	}
> > +	/* Sort in ascending order and use a triangular filter */
> > +	qsort(power, 5, sizeof(*power), cmp_u64);
> > +	return DIV_ROUND_UP(power[1] + 2 * power[2] + power[3], 4);
> > +}
> > +
> > +/**
> > + * SUBTEST: freq_power
-------------------- ^
Test names should use '-' as separator but testplan expects spaces:

* SUBTEST: freq power

> > + * Description: Validates if running at lower frequencies saves power
> > + * Run type: FULL
------- ^^^^^^^^
We dropped 'Run type' field, see patch by Mauro:
("commit ada49eb7de576858b63e231ebfd850cfe864cefe")
    tests: Intel Xe: drop Run type field

> > + */
> > +static void test_freq_power(int fd, int gt_id, struct drm_xe_engine_class_instance *hwe)
> > +{
> > +	uint32_t rp0, rpn, vm;
> > +	uint64_t ahnd;
> > +	struct igt_power gpu;
> > +	struct {
> > +		uint64_t power;
> > +		uint32_t freq;
> > +	} min, max;
> > +	igt_spin_t *spin;
> > +
> > +	/* Run for engines belonging to the gt */
> > +	if (gt_id != hwe->gt_id)
> > +		return;
> > +
> > +	igt_power_open(fd, &gpu, "gpu");
> > +
> > +	rpn = get_freq(fd, gt_id, "rpn");
> > +	rp0 = get_freq(fd, gt_id, "rp0");
> > +
> > +	vm = xe_vm_create(fd, 0, 0);
> > +	ahnd = intel_allocator_open(fd, vm, INTEL_ALLOCATOR_RELOC);
> > +	spin = igt_spin_new(fd, .ahnd = ahnd, .vm = vm, .hwe = hwe);
> > +
> > +	igt_assert(set_freq(fd, gt_id, "min", rpn) > 0);
> > +	igt_assert(set_freq(fd, gt_id, "max", rpn) > 0);
> > +	min.freq = get_freq(fd, gt_id, "act");
> > +	min.power = measure_power(fd, &gpu);
> > +
> > +	igt_assert(set_freq(fd, gt_id, "min", rp0) > 0);
> > +	igt_assert(set_freq(fd, gt_id, "max", rp0) > 0);
> > +	max.freq = get_freq(fd, gt_id, "act");
> > +	max.power = measure_power(fd, &gpu);
> > +
> > +	igt_info("Engine %s:%d  min:%lumW @ %uMHz, max:%lumW @ %uMHz\n",
> > +		 xe_engine_class_string(hwe->engine_class), hwe->engine_instance,
> > +		 min.power, min.freq, max.power, max.freq);
> > +
> > +	igt_spin_free(fd, spin);
> > +	put_ahnd(ahnd);
> > +	xe_vm_destroy(fd, vm);
> > +	igt_power_close(&gpu);
> > +
> > +	/* Max power should be greater than min power + 10% of min power */
> nit: reword: power at max_freq should be at least 10% greater than
> power at min_freq?
> > +	igt_assert_f((11 * min.power < 10 * max.power),
> > +		     "%s:%d did not conserve power when setting lower frequency!\n",
> > +		     xe_engine_class_string(hwe->engine_class), hwe->engine_instance);
> > +}
> > +
> >   igt_main
> >   {
> >   	struct drm_xe_engine_class_instance *hwe;
> > @@ -475,6 +552,17 @@ igt_main
> >   		}
> >   	}
> > +	igt_describe("Validates power measured at lower frequencies");
> nit: reword? Validate more power is consumed at higher frequencies?
> > +	igt_subtest("freq_power") {
------------------------ ^
imho better: low-freq-power

Regards,
Kamil

> > +		/* FIXME: Remove skip once hwmon is added */
> > +		igt_skip_on(xe_has_vram(fd));
> > +		xe_for_each_gt(fd, gt) {
> > +			xe_for_each_hw_engine(fd, hwe) {
> > +				test_freq_power(fd, gt, hwe);
> > +			}
> > +		}
> > +	}
> > +
> 
> LGTM,
> 
> Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
> 
> 
> >   	igt_fixture {
> >   		xe_for_each_gt(fd, gt) {
> >   			set_freq(fd, gt, "min", stash_min);