[Intel-gfx] [PATCH v6 09/11] drm/i915/perf: allow holding preemption on filtered ctx

[Chris Wilson]

Quoting Lionel Landwerlin (2019-07-01 12:34:35)
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index f92bace9caff..012d6d7f54e2 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -2104,6 +2104,14 @@ static int eb_oa_config(struct i915_execbuffer *eb)
>         if (err)
>                 return err;
>  
> +       /*
> +        * If the perf stream was opened with hold preemption, flag the
> +        * request properly so that the priority of the request is bumped once
> +        * it reaches the execlist ports.
> +        */
> +       if (eb->i915->perf.oa.exclusive_stream->hold_preemption)
> +               eb->request->flags |= I915_REQUEST_FLAGS_PERF;

Just to reassure myself that this is the behaviour you:

If the exclusive_stream is changed before the request is executed, it is
likely that we no longer notice the earlier preemption-protection. This
should not matter because the listener is no longer interested in those
events?
-Chris