Re: [PATCH i-g-t 2/2] tests/xe_pmu: Add frequency test

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 4/9/2025 4:06 AM, Kamil Konieczny wrote:
> Hi,
> On 2025-04-09 at 15:28:59 +0530, Riana Tauro wrote:
>> Hi Vinay
>>
>> On 4/8/2025 5:14 AM, Vinay Belgaumkar wrote:
>>> Add a basic test that uses PMU to read GT actual and requested
>>> frequencies while running a workload.
>>>
>>> v2: Rebase and comments (Riana)
>>>
>>> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
>>> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
>>> Cc: Riana Tauro <riana.tauro@intel.com>
>>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>>> ---
>>>    tests/intel/xe_pmu.c | 128 ++++++++++++++++++++++++++++++++++++++++++-
>>>    1 file changed, 127 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/tests/intel/xe_pmu.c b/tests/intel/xe_pmu.c
>>> index 175bbf374..fbac9c798 100644
>>> --- a/tests/intel/xe_pmu.c
>>> +++ b/tests/intel/xe_pmu.c
>>> @@ -376,6 +376,94 @@ static void test_gt_c6_idle(int xe, unsigned int gt)
>>>    	close(pmu_fd);
>>>    }
>>> +/**
>>> + * SUBTEST: gt-frequency
>>> + * Description: Validate we can collect accurate frequency PMU stats
>>> + *		while running a workload.
>>> + */
>>> +static void test_gt_frequency(int fd, struct drm_xe_engine_class_instance *eci)
>>> +{
>>> +	struct xe_cork *cork = NULL;
>>> +	uint64_t end[2], start[2];
>>> +	unsigned long config_rq_freq, config_act_freq;
>>> +	double min[2], max[2];
>>> +	uint32_t gt = eci->gt_id;
>>> +	uint32_t orig_min = xe_gt_get_freq(fd, eci->gt_id, "min");
>>> +	uint32_t orig_max = xe_gt_get_freq(fd, eci->gt_id, "max");
>>> +	uint32_t vm;
>>> +	int pmu_fd[2];
>>> +
>>> +	config_rq_freq = get_event_config(gt, NULL, "gt-requested-frequency");
>>> +	pmu_fd[0] = open_group(fd, config_rq_freq, -1);
>>> +
>>> +	config_act_freq = get_event_config(gt, NULL, "gt-actual-frequency");
>>> +	pmu_fd[1] = open_group(fd, config_act_freq, pmu_fd[0]);
>>> +
>>> +	vm = xe_vm_create(fd, 0, 0);
>>> +
>>> +	cork = xe_cork_create_opts(fd, eci, vm, 1, 1);
>>> +	xe_cork_sync_start(fd, cork);
>>> +
>>> +	/*
>>> +	 * Set GPU to min frequency and read PMU counters.
>>> +	 */
>>> +	igt_assert(xe_gt_set_freq(fd, gt, "max", orig_min) > 0);
>>> +	igt_assert(xe_gt_get_freq(fd, gt, "max") == orig_min);
>>> +
>>> +	pmu_read_multi(pmu_fd[0], 2, start);
>>> +	usleep(SLEEP_DURATION * USEC_PER_SEC);
>>> +	pmu_read_multi(pmu_fd[0], 2, end);
>>> +
>>> +	min[0] = (end[0] - start[0]);
>>> +	min[1] = (end[1] - start[1]);
>>> +
>>> +	/*
>>> +	 * Set GPU to max frequency and read PMU counters.
>>> +	 */
>>> +	igt_assert(xe_gt_set_freq(fd, gt, "max", orig_max) > 0);
>>> +	igt_assert(xe_gt_get_freq(fd, gt, "max") == orig_max);
>>> +	igt_assert(xe_gt_set_freq(fd, gt, "min", orig_max) > 0);
>>> +	igt_assert(xe_gt_get_freq(fd, gt, "min") == orig_max);
>>> +
>>> +	pmu_read_multi(pmu_fd[0], 2, start);
>>> +	usleep(SLEEP_DURATION * USEC_PER_SEC);
>>> +	pmu_read_multi(pmu_fd[0], 2, end);
>>> +
>>> +	max[0] = (end[0] - start[0]);
>>> +	max[1] = (end[1] - start[1]);
>>> +
>>> +	xe_cork_sync_end(fd, cork);
>>> +
>>> +	/*
>>> +	 * Restore min/max.
>>> +	 */
>>> +	igt_assert(xe_gt_set_freq(fd, gt, "min", orig_min) > 0);
>>> +	igt_assert(xe_gt_get_freq(fd, gt, "min") == orig_min);
>>> +
>>> +	igt_info("Minimum frequency: requested %.1f, actual %.1f\n",
>>> +		 min[0], min[1]);
>>> +	igt_info("Maximum frequency: requested %.1f, actual %.1f\n",
>>> +		 max[0], max[1]);
>>> +
>>> +	close(pmu_fd[0]);
>>> +	close(pmu_fd[1]);
>>> +
>>> +	if (cork)
>>> +		xe_cork_destroy(fd, cork);
>>> +
>>> +	xe_vm_destroy(fd, vm);
>>> +
>>> +	close(pmu_fd[0]);
>>> +	close(pmu_fd[1]);
>>> +
>>> +	assert_within_epsilon(min[0], orig_min, tolerance);
>>> +	/*
>>> +	 * On thermally throttled devices we cannot be sure maximum frequency
>>> +	 * can be reached so use larger tolerance downwards.
>>> +	 */
>>> +	assert_within_epsilon_up_down(max[0], orig_max, tolerance, 0.15f);
>>> +}
>>> +
>>>    static unsigned int enable_and_provision_vfs(int fd)
>>>    {
>>>    	unsigned int gt, num_vfs;
>>> @@ -429,8 +517,9 @@ static void disable_vfs(int fd)
>>>    igt_main
>>>    {
>>> -	int fd, gt;
>>> +	int fd, gt, num_gts;
>>>    	struct drm_xe_engine_class_instance *eci;
>>> +	uint32_t *stash_min, *stash_max;
>>>    	igt_fixture {
>>>    		fd = drm_open_driver(DRIVER_XE);
>>> @@ -482,6 +571,43 @@ igt_main
>>>    			disable_vfs(fd);
>>>    	}
>>> +	igt_subtest_group {
> Add here:
> 	bool has_freq0_node, needs_restore = false;
>
>>> +		igt_fixture {
>>> +			igt_require(xe_sysfs_gt_has_node(fd, 0, "freq0"));
> Move this require into subtest. If you need it here then remember its
> value for later use:
> 	has_freq0_node = xe_sysfs_gt_has_node(fd, 0, "freq0");
>
>>> +			num_gts = xe_number_gt(fd);
>>> +
> So here start with if:
>
> 	if (has_freq0_node) {
>
>>> +			stash_min = (uint32_t *) malloc(sizeof(uint32_t) * num_gts);
>>> +			stash_max = (uint32_t *) malloc(sizeof(uint32_t) * num_gts);
>>> +
>>> +			xe_for_each_gt(fd, gt) {
>>> +				stash_min[gt] = xe_gt_get_freq(fd, gt, "min");
>>> +				stash_max[gt] = xe_gt_get_freq(fd, gt, "max");
>> This can be moved inside the igt_subtest with local variables since it's
>> only one test. The subtest group is executed for all the other tests too
>>
>> Thanks
>> Riana> +			}
>>> +		}
>>> +
>>> +		igt_describe("Validate PMU GT freq measured is within the tolerance");
>>> +		igt_subtest_with_dynamic("gt-frequency") {
> needs_restore = true;
>
>>> +			xe_for_each_gt(fd, gt) {
>>> +				igt_dynamic_f("gt%u", gt)
>>> +				xe_for_each_engine(fd, eci) {
>>> +					if (gt == eci->gt_id) {
>>> +						test_gt_frequency(fd, eci);
>>> +						break;
>>> +					}
>>> +				}
>>> +			}
>>> +		}
>>> +
>>> +		igt_fixture {
> 			if (needs_restore) {

ok. Thanks,

Vinay.

> 				
>>> +			xe_for_each_gt(fd, gt) {
>>> +				xe_gt_set_freq(fd, gt, "max", stash_max[gt]);
>>> +				xe_gt_set_freq(fd, gt, "min", stash_min[gt]);
>>> +			}
>>> +			free(stash_min);
>>> +			free(stash_max);
> 			} /* restore */
>
> Regards,
> Kamil
>
>>> +		}
>>> +	}
>>> +
>>>    	igt_fixture {
>>>    		close(fd);
>>>    	}