[igt-dev] [PATCH i-g-t v2 1/2] tests/intel/xe_guc_pc: Add freq-power test
Riana Tauro
riana.tauro at intel.com
Tue Sep 26 05:44:51 UTC 2023
On 9/25/2023 7:03 PM, Rodrigo Vivi wrote:
> On Mon, Sep 25, 2023 at 03:24:14PM +0530, Riana Tauro wrote:
>> Hi Rodrigo
>>
>> On 9/21/2023 9:28 PM, Rodrigo Vivi wrote:
>>> On Thu, Sep 21, 2023 at 02:25:07PM +0530, 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 consumed
>>>> at lower frequencies is lesser than higher frequencies.
>>>>
>>>> v2: Remove Run Type
>>>> change test name (Kamil)
>>>> change test documentation and comments (Vinay)
>>>>
>>>> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
>>>> Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar 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 0327d8e0e..2b3d08fcb 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"
>>>> @@ -382,6 +383,82 @@ 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
>>>> + * Description: Validates power consumed at higher frequencies is more than
>>>> + * power consumed at lower frequencies.
>>>> + */
>>>> +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);
>>>> +
>>>> + /* 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);
>>>
>>> What exactly are we trying to test here with this case?
>>> This creates an artificial KPI that might not be true for the broader range
>>> of SKUs and generations out there. And then when it fails what should we do?
>>> come here and update the test case?
>> This test was a port from i915 [rps-power & slpc-power]
>>
>> The commit message for the i915 tests is based on an assumption
>>
>> "at lower frequencies, not only do we run
>> slower, but we save power compared to higher frequencies."
>>
>> I went through the failures there hasn't been a fix anywhere.
>>
>> But shouldn't the power consumed at lower frequencies be lesser than higher
>> (removing the 10% in the above condition)?
>
> well, our hw is very complex. We have many power gating mechanisms that
> might be saving power even when we select higher frequencies, but are
> not exercising the entire GPU.
>
> But even if we create a test that are capable of exercising all the EUs,
> CSes, fixed functions and everything, maybe finishing the workload quickly
> on higher frequencies, might trigger more deep lower power states that could
> save power over the slow workload taking longer to execute.
>
Thanks for the clarification. Will drop this test
Thanks,
Riana
>>
>> I will drop this test if not necessary
>
> yes, please let's drop it. I'm in favor of killing the i915 as well >
> Thanks,
> Rodrigo.
>
>>
>> Thanks
>> Riana Tauro
>>>
>>>> +}
>>>> +
>>>> igt_main
>>>> {
>>>> struct drm_xe_engine_class_instance *hwe;
>>>> @@ -472,6 +549,17 @@ igt_main
>>>> }
>>>> }
>>>> + igt_describe("Validate more power is consumed at higher frequencies");
>>>> + igt_subtest("freq-power") {
>>>> + /* 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);
>>>> + }
>>>> + }
>>>> + }
>>>> +
>>>> igt_fixture {
>>>> xe_for_each_gt(fd, gt) {
>>>> set_freq(fd, gt, "min", stash_min);
>>>> --
>>>> 2.40.0
>>>>
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