[Intel-gfx] [PATCH i-g-t 1/2] i915/perf: Stress opening of new perf streams against existing contexts

[Kamil Konieczny]

Hi,

On 2023-01-31 at 10:17:30 +0100, Janusz Krzysztofik wrote:
> From: Chris Wilson <chris.p.wilson at linux.intel.com>
> 
> Try opening the perf stream while there is a flurry of activity on the
> system, both new and old contexts. This will exercise the ability of the
> driver to modify those contexts to work with perf.
> 
> References: https://gitlab.freedesktop.org/drm/intel/-/issues/6333
> Signed-off-by: Chris Wilson <chris.p.wilson at linux.intel.com>
> Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
> Cc: Andi Shyti <andi.shyti at linux.intel.com>
> ---
>  tests/i915/perf.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/tests/i915/perf.c b/tests/i915/perf.c
> index dd1f1ac399..e33cacc443 100644
> --- a/tests/i915/perf.c
> +++ b/tests/i915/perf.c
> @@ -4885,6 +4885,71 @@ test_whitelisted_registers_userspace_config(void)
>  	i915_perf_remove_config(drm_fd, config_id);
>  }
>  
> +static void test_open_race(const struct intel_execution_engine2 *e, int timeout)
> +{
> +	int *done;
> +
> +	done = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
> +	igt_assert(done != MAP_FAILED);
> +
> +	igt_fork(child, 1) {
> +		uint64_t properties[] = {
> +			DRM_I915_PERF_PROP_SAMPLE_OA, true,
> +			DRM_I915_PERF_PROP_OA_METRICS_SET, test_set->perf_oa_metrics_set,
> +			DRM_I915_PERF_PROP_OA_FORMAT, test_set->perf_oa_format,
> +			DRM_I915_PERF_PROP_OA_EXPONENT, oa_exp_1_millisec,
> +		};
> +		struct drm_i915_perf_open_param param = {
> +			.flags = I915_PERF_FLAG_FD_CLOEXEC,
> +			.num_properties = sizeof(properties) / 16,
> +			.properties_ptr = to_user_pointer(properties),
> +		};
> +		unsigned long count = 0;
> +
> +		do {
> +			__perf_close(__perf_open(drm_fd, &param, false));
> +			count++;
> +		} while (!READ_ONCE(*done));
> +
> +		igt_info("Completed %lu cycles\n", count);
> +	}
> +
> +	for (int persistence = 0; persistence <= 1; persistence++) {
> +		igt_fork(child, sysconf(_SC_NPROCESSORS_ONLN)) {
> +			int i915 = gem_reopen_driver(drm_fd);
> +
> +			do {
> +				igt_spin_t *spin;
> +				uint64_t ahnd;
> +				uint32_t ctx;
> +
> +				ctx = gem_context_create_for_engine(i915, e->class, e->instance);
> +				gem_context_set_persistence(i915, ctx, persistence);
> +
> +				spin = __igt_spin_new(i915, ctx, .ahnd = ahnd);
> +				for (int i = random() % 7; i--; ) {
> +					if (random() & 1) {
> +						igt_spin_end(spin);
> +						gem_sync(i915, spin->handle);
> +						igt_spin_reset(spin);
> +					}
> +					gem_execbuf(i915, &spin->execbuf);
> +				}
> +
> +				gem_context_destroy(i915, ctx);
> +				igt_spin_free(i915, spin);
> +				put_ahnd(ahnd);
> +			} while (!READ_ONCE(*done));
> +		}
> +	}
> +
> +	sleep(timeout);
> +	*done = 1;
> +	igt_waitchildren();
> +
> +	munmap(done, 4096);
> +}
> +
>  static unsigned
>  read_i915_module_ref(void)
>  {
> @@ -5259,6 +5324,15 @@ igt_main
>  	igt_subtest("whitelisted-registers-userspace-config")
>  		test_whitelisted_registers_userspace_config();
>  

Please add description to new test.

Regards,
Kamil

> +	igt_subtest_with_dynamic("open-race") {
> +		const struct intel_execution_engine2 *e;
> +
> +		for_each_physical_engine(drm_fd, e)
> +			if (e->class == I915_ENGINE_CLASS_RENDER)
> +				igt_dynamic_f("%s", e->name)
> +					test_open_race(e, 5);
> +	}
> +
>  	igt_fixture {
>  		/* leave sysctl options in their default state... */
>  		write_u64_file("/proc/sys/dev/i915/oa_max_sample_rate", 100000);
> -- 
> 2.25.1
>