Re: [igt-dev] [PATCH i-g-t 2/2] tests/xe_spin_batch: spin-fixed-duration

["Bernatowicz, Marcin" <marcin.bernatowicz@linux.intel.com>]

On 8/7/2023 8:56 AM, Zbigniew Kempczyński wrote:
> On Fri, Aug 04, 2023 at 10:24:54AM +0000, Marcin Bernatowicz wrote:
>> Basic test for xe_spin with fixed duration.
>>
>> Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
>> ---
>>   tests/xe/xe_spin_batch.c | 59 ++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 59 insertions(+)
>>
>> diff --git a/tests/xe/xe_spin_batch.c b/tests/xe/xe_spin_batch.c
>> index 26f9daf36..bdad3bab9 100644
>> --- a/tests/xe/xe_spin_batch.c
>> +++ b/tests/xe/xe_spin_batch.c
>> @@ -1,8 +1,10 @@
>>   #include "igt.h"
>> +#include "igt_syncobj.h"
>>   #include "lib/intel_reg.h"
>>   #include "xe_drm.h"
>>   #include "xe/xe_ioctl.h"
>>   #include "xe/xe_query.h"
>> +#include "xe/xe_spin.h"
>>   
>>   /**
>>    * TEST: Tests for spin batch submissons.
>> @@ -138,6 +140,60 @@ static void spin_all(int fd, int gt, int class)
>>   	xe_vm_destroy(fd, vm);
>>   }
>>   
>> +/**
>> + * SUBTEST: spin-fixed-duration
>> + * Description: Basic test which validates the functionality of xe_spin with fixed duration.
>> + * Run type: FULL
>> + */
>> +static void xe_spin_fixed_duration(int fd)
>> +{
>> +	uint64_t ahnd;
>> +	uint32_t vm;
>> +	unsigned int exec_queue;
>> +	uint32_t bo;
>> +	size_t bo_size;
>> +	struct xe_spin *spin;
>> +	struct xe_spin_opts spin_opts = {};
>> +	struct drm_xe_sync sync = {
>> +		.handle = syncobj_create(fd, 0),
>> +		.flags = DRM_XE_SYNC_SYNCOBJ | DRM_XE_SYNC_SIGNAL,
>> +	};
>> +	struct drm_xe_exec exec = {
>> +		.num_batch_buffer = 1,
>> +		.num_syncs = 1,
>> +		.syncs = to_user_pointer(&sync),
>> +	};
>> +	struct timespec tv;
>> +	uint64_t duration_ns = NSEC_PER_SEC / 10; /* 100ms */
>> +
>> +	vm = xe_vm_create(fd, 0, 0);
>> +	exec_queue = xe_exec_queue_create_class(fd, vm, DRM_XE_ENGINE_CLASS_COPY);
>> +	ahnd = intel_allocator_open(fd, 0, INTEL_ALLOCATOR_RELOC);
>> +	bo_size = ALIGN(sizeof(*spin) + xe_cs_prefetch_size(fd), xe_get_default_alignment(fd));
>> +	bo = xe_bo_create(fd, 0, vm, bo_size);
>> +	spin = xe_bo_map(fd, bo, bo_size);
>> +	spin_opts.addr = intel_allocator_alloc_with_strategy(ahnd, bo, bo_size, 0, ALLOC_STRATEGY_LOW_TO_HIGH);
>> +	spin_opts.ctx_ticks = duration_to_ctx_ticks(fd, 0, duration_ns);
>> +	xe_vm_bind_sync(fd, vm, bo, 0, spin_opts.addr, bo_size);
>> +	xe_spin_init(spin, &spin_opts);
>> +	exec.exec_queue_id = exec_queue;
>> +	exec.address = spin_opts.addr;
>> +
>> +	igt_gettime(&tv);
>> +	xe_exec(fd, &exec);
>> +	xe_spin_wait_started(spin);
>> +	igt_assert(syncobj_wait(fd, &sync.handle, 1, INT64_MAX, 0, NULL));
>> +	igt_info("%.0fms spin took %.1fms\n", duration_ns * 1e-6, igt_nsec_elapsed(&tv) * 1e-6);
> 
> I would assume some error margin (let's say 10% of duration_ns) and assert
> if spinner doesn't end in this time. igt_info() is not enough imo if
> we want to be sure spinner runs in fixed time.
> 
This may be a bit tricky, single run may actually exceed 10%, and it 
also depends on the drm debug level parameter used.

We can complicate the sample a bit and take median of few execs:

	igt_stats_init_with_size(&stats, 5);
	for (i = 0; i < 5; ++i) {
		igt_gettime(&tv);
		xe_exec(fd, &exec);
		xe_spin_wait_started(spin);
		igt_assert(syncobj_wait(fd, &sync.handle, 1, INT64_MAX, 0, NULL));
		igt_stats_push_float(&stats, igt_nsec_elapsed(&tv) * 1e-6);
		syncobj_reset(fd, &sync.handle, 1);
		igt_debug("i=%d %.2fms\n", i, stats.values_f[i]);
	}
	elapsed_ms = igt_stats_get_median(&stats);
	igt_info("%.0fms spin took %.2fms (median)\n", duration_ns * 1e-6, 
elapsed_ms);
	igt_assert(elapsed_ms < duration_ns * 1.5e-6 && elapsed_ms > 
duration_ns * 0.5e-6);

--
marcin
  --
> Zbigniew
> 
>> +
>> +	xe_vm_unbind_sync(fd, vm, 0, spin_opts.addr, bo_size);
>> +	syncobj_destroy(fd, sync.handle);
>> +	gem_munmap(spin, bo_size);
>> +	gem_close(fd, bo);
>> +	xe_exec_queue_destroy(fd, exec_queue);
>> +	xe_vm_destroy(fd, vm);
>> +	put_ahnd(ahnd);
>> +}
>> +
>>   igt_main
>>   {
>>   	struct drm_xe_engine_class_instance *hwe;
>> @@ -163,6 +219,9 @@ igt_main
>>   				spin_all(fd, gt, class);
>>   	}
>>   
>> +	igt_subtest("spin-fixed-duration")
>> +		xe_spin_fixed_duration(fd);
>> +
>>   	igt_fixture
>>   		drm_close_driver(fd);
>>   }
>> -- 
>> 2.30.2
>>