[Intel-gfx] [PATCH i-g-t 1/3] lib/dummyload: Support returning output fence

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-12-19 15:45:41)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Support creating spin batches which return an output fence using new
> __igt_spin_batch_new_fence / igt_spin_batch_new_fence API.
> 
> This will be used fromthe perf_pmu at interrupts test to ensure user
> interrupt generation from a batch with controlled duration.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  lib/igt_dummyload.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++-------
>  lib/igt_dummyload.h | 10 +++++++++
>  2 files changed, 67 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/igt_dummyload.c b/lib/igt_dummyload.c
> index d19b4e5ea3d2..ef08ad580246 100644
> --- a/lib/igt_dummyload.c
> +++ b/lib/igt_dummyload.c
> @@ -70,9 +70,9 @@ fill_reloc(struct drm_i915_gem_relocation_entry *reloc,
>         reloc->write_domain = write_domains;
>  }
>  
> -static void emit_recursive_batch(igt_spin_t *spin,
> -                                int fd, uint32_t ctx, unsigned engine,
> -                                uint32_t dep)
> +static int emit_recursive_batch(igt_spin_t *spin,
> +                               int fd, uint32_t ctx, unsigned engine,
> +                               uint32_t dep, bool out_fence)
>  {
>  #define SCRATCH 0
>  #define BATCH 1
> @@ -87,6 +87,7 @@ static void emit_recursive_batch(igt_spin_t *spin,
>  
>         nengine = 0;
>         if (engine == -1) {
> +               igt_assert_eq(out_fence, false);

Didn't fancy merging the fences together to return a composite out_fence?

>                 for_each_engine(fd, engine)
>                         if (engine)
>                                 engines[nengine++] = engine;
> @@ -165,22 +166,31 @@ static void emit_recursive_batch(igt_spin_t *spin,
>         execbuf.buffers_ptr = to_user_pointer(obj + (2 - execbuf.buffer_count));
>         execbuf.rsvd1 = ctx;
>  
> +       if (out_fence)
> +               execbuf.flags = I915_EXEC_FENCE_OUT;

if (out_fence)
	execbuf.flags |= I915_EXEC_FENCE_OUT;

Just to make future changes easier?

Might also be good to insert a igt_require(gem_has_exec_fence(fd)) here
as well. (Or earlier?)

> +igt_spin_t *__igt_spin_batch_new_fence(int fd,
> +                                      uint32_t ctx,
> +                                      unsigned engine);
> +
> +igt_spin_t *igt_spin_batch_new_fence(int fd,
> +                                    uint32_t ctx,
> +                                    unsigned engine);

Ok for now, I expect these will mangled into a new spin-batch factory
later on.

With an igt_require(),
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

If you want to merge the N engines' out_fences into one, that would save
me a task.
-Chris