[Intel-gfx] [PATCH i-g-t 2/2] tests/perf_pmu: Simplify interrupt testing

Chris Wilson chris at chris-wilson.co.uk
Fri Dec 22 13:51:11 UTC 2017


Quoting Tvrtko Ursulin (2017-12-22 13:13:48)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Rather than calibrate and emit nop batches, use a manually signalled chain
> of spinners to generate the desired interrupts.
> 
> v2: Two flavours of interrupt generation. (Chris Wilson)
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  tests/perf_pmu.c | 141 +++++++++++++++++++++++++++----------------------------
>  1 file changed, 69 insertions(+), 72 deletions(-)
> 
> diff --git a/tests/perf_pmu.c b/tests/perf_pmu.c
> index db7696115a7b..54707dea63af 100644
> --- a/tests/perf_pmu.c
> +++ b/tests/perf_pmu.c
> @@ -799,94 +799,85 @@ static void cpu_hotplug(int gem_fd)
>         assert_within_epsilon(val, ref, tolerance);
>  }
>  
> -static unsigned long calibrate_nop(int fd, const uint64_t calibration_us)
> +static void
> +test_interrupts(int gem_fd)
>  {
> -       const uint64_t cal_min_us = calibration_us * 3;
> -       const unsigned int tolerance_pct = 10;
> -       const uint32_t bbe = MI_BATCH_BUFFER_END;
> -       const unsigned int loops = 17;
> -       struct drm_i915_gem_exec_object2 obj = {};
> -       struct drm_i915_gem_execbuffer2 eb = {
> -               .buffer_count = 1, .buffers_ptr = to_user_pointer(&obj),
> -       };
> -       struct timespec t_begin = { };
> -       uint64_t size, last_size, ns;
> -
> -       igt_nsec_elapsed(&t_begin);
> -
> -       size = 256 * 1024;
> -       do {
> -               struct timespec t_start = { };
> +       const unsigned int test_duration_ms = 1000;
> +       const int target = 30;
> +       igt_spin_t *spin[target];
> +       struct pollfd pfd;
> +       uint64_t idle, busy;
> +       int fence_fd;
> +       int fd;
>  
> -               obj.handle = gem_create(fd, size);
> -               gem_write(fd, obj.handle, size - sizeof(bbe), &bbe,
> -                         sizeof(bbe));
> -               gem_execbuf(fd, &eb);
> -               gem_sync(fd, obj.handle);
> +       gem_quiescent_gpu(gem_fd);
>  
> -               igt_nsec_elapsed(&t_start);
> +       fd = open_pmu(I915_PMU_INTERRUPTS);
>  
> -               for (int loop = 0; loop < loops; loop++)
> -                       gem_execbuf(fd, &eb);
> -               gem_sync(fd, obj.handle);
> +       /* Queue spinning batches. */
> +       for (int i = 0; i < target; i++) {
> +               spin[i] = igt_spin_batch_new_fence(gem_fd, 0, I915_EXEC_RENDER);
> +               if (i == 0) {
> +                       fence_fd = spin[i]->out_fence;
> +               } else {
> +                       int old_fd = fence_fd;
>  
> -               ns = igt_nsec_elapsed(&t_start);
> +                       fence_fd = sync_fence_merge(old_fd,
> +                                                   spin[i]->out_fence);
> +                       close(old_fd);
> +               }
>  
> -               gem_close(fd, obj.handle);
> +               igt_assert(fence_fd >= 0);
> +       }
> +
> +       /* Wait for idle state. */
> +       idle = pmu_read_single(fd);
> +       do {
> +               busy = idle;
> +               usleep(1e3);
> +               idle = pmu_read_single(fd);
> +       } while (idle != busy);
>  
> -               last_size = size;
> -               size = calibration_us * 1000 * size * loops / ns;
> -               size = ALIGN(size, sizeof(uint32_t));
> -       } while (igt_nsec_elapsed(&t_begin) / 1000 < cal_min_us ||
> -                abs(size - last_size) > (size * tolerance_pct / 100));
> +       /* Arm batch expiration. */
> +       for (int i = 0; i < target; i++)

Joonas would point out the benefit of using a local to get around col80.

> +               igt_spin_batch_set_timeout(spin[i],
> +                                          (i + 1) * test_duration_ms * 1e6
> +                                          / target);
> +
> +       /* Wait for last batch to finish. */
> +       pfd.events = POLLIN;
> +       pfd.fd = fence_fd;
> +       igt_assert_eq(poll(&pfd, 1, 2 * test_duration_ms), 1);
> +       close(fence_fd);
>  
> -       return size;
> +       /* Free batches. */
> +       for (int i = 0; i < target; i++)
> +               igt_spin_batch_free(gem_fd, spin[i]);
> +
> +       /* Check at least as many interrupts has been generated. */
> +       busy = pmu_read_single(fd) - idle;
> +       close(fd);
> +
> +       igt_assert_lte(target, busy);

Looks good.

>  }
>  
>  static void
> -test_interrupts(int gem_fd)
> +test_interrupts_sync(int gem_fd)
>  {
> -       const uint32_t bbe = MI_BATCH_BUFFER_END;
>         const unsigned int test_duration_ms = 1000;
> -       struct drm_i915_gem_exec_object2 obj = { };
> -       struct drm_i915_gem_execbuffer2 eb = {
> -               .buffers_ptr = to_user_pointer(&obj),
> -               .buffer_count = 1,
> -               .flags = I915_EXEC_FENCE_OUT,
> -       };
> -       unsigned long sz;
> -       igt_spin_t *spin;
>         const int target = 30;
> +       igt_spin_t *spin[target];
>         struct pollfd pfd;
>         uint64_t idle, busy;
>         int fd;
>  
> -       sz = calibrate_nop(gem_fd, test_duration_ms * 1000 / target);
>         gem_quiescent_gpu(gem_fd);
>  
>         fd = open_pmu(I915_PMU_INTERRUPTS);
> -       spin = igt_spin_batch_new(gem_fd, 0, 0, 0);
> -
> -       obj.handle = gem_create(gem_fd, sz);
> -       gem_write(gem_fd, obj.handle, sz - sizeof(bbe), &bbe, sizeof(bbe));
> -
> -       pfd.events = POLLIN;
> -       pfd.fd = -1;
> -       for (int i = 0; i < target; i++) {
> -               int new;
>  
> -               /* Merge all the fences together so we can wait on them all */
> -               gem_execbuf_wr(gem_fd, &eb);
> -               new = eb.rsvd2 >> 32;
> -               if (pfd.fd == -1) {
> -                       pfd.fd = new;
> -               } else {
> -                       int old = pfd.fd;
> -                       pfd.fd = sync_fence_merge(old, new);
> -                       close(old);
> -                       close(new);
> -               }
> -       }
> +       /* Queue spinning batches. */
> +       for (int i = 0; i < target; i++)
> +               spin[i] = __igt_spin_batch_new_fence(gem_fd, 0, 0);
>  
>         /* Wait for idle state. */
>         idle = pmu_read_single(fd);
> @@ -896,13 +887,16 @@ test_interrupts(int gem_fd)
>                 idle = pmu_read_single(fd);
>         } while (idle != busy);
>  
> -       /* Install the fences and enable signaling */
> -       igt_assert_eq(poll(&pfd, 1, 10), 0);
> +       /* Process the batch queue. */
> +       pfd.events = POLLIN;
> +       for (int i = 0; i < target; i++) {
> +               const unsigned int timeout_ms = test_duration_ms / target;
>  
> -       /* Unplug the calibrated queue and wait for all the fences */
> -       igt_spin_batch_free(gem_fd, spin);
> -       igt_assert_eq(poll(&pfd, 1, 2 * test_duration_ms), 1);
> -       close(pfd.fd);
> +               pfd.fd = spin[i]->out_fence;
> +               igt_spin_batch_set_timeout(spin[i], timeout_ms * 1e6);
> +               igt_assert_eq(poll(&pfd, 1, 2 * timeout_ms), 1);

(Going outside the purpose of this test, but I was thinking

igt_assert_eq(poll(&pfd, 1, timeout_ms), 0);
igt_spin_batch_end(gem_fd, spin[i]);
igt_assert_eq(poll(&pfd, 1, timeout_ms), 1);

would be fun and a bit different.)

> +               igt_spin_batch_free(gem_fd, spin[i]);
> +       }
>  
>         /* Check at least as many interrupts has been generated. */
>         busy = pmu_read_single(fd) - idle;
> @@ -1184,6 +1178,9 @@ igt_main
>         igt_subtest("interrupts")
>                 test_interrupts(fd);
>  
> +       igt_subtest("interrupts-sync")
> +               test_interrupts_sync(fd);
> +
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris


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