Re: [igt-dev] [PATCH i-g-t 3/4] lib/igt_gt: Add compute engine

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Thu, 21 Oct 2021 00:33:21 -0700, Zbigniew Kempczyński wrote:
>
> On Thu, Oct 21, 2021 at 10:05:07AM +0530, priyanka.dandamudi@intel.com wrote:
> > From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> >
> > Add compute (CCS) engine. Add this to the IGT
> > structure to allow gem tests to execute.
> >
> > Signed-off-by: Stuart Summers <stuart.summers@intel.com>
> > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> > Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi@intel.com>
> > Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
> > Cc: Arjun Melkaveri <arjun.melkaveri@intel.com>
> > ---
> >  lib/igt_gt.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/lib/igt_gt.c b/lib/igt_gt.c
> > index a0ba04cc..80fb65ca 100644
> > --- a/lib/igt_gt.c
> > +++ b/lib/igt_gt.c
> > @@ -604,6 +604,10 @@ const struct intel_execution_engine2 intel_execution_engines2[] = {
> >	{ "vcs1", I915_ENGINE_CLASS_VIDEO, 1, I915_EXEC_BSD | I915_EXEC_BSD_RING2 },
> >	{ "vcs2", I915_ENGINE_CLASS_VIDEO, 2, -1 },
> >	{ "vecs0", I915_ENGINE_CLASS_VIDEO_ENHANCE, 0, I915_EXEC_VEBOX },
> > +	{ "ccs0", I915_ENGINE_CLASS_COMPUTE, 0 , -1},
> > +	{ "ccs1", I915_ENGINE_CLASS_COMPUTE, 1 , -1},
> > +	{ "ccs2", I915_ENGINE_CLASS_COMPUTE, 2 , -1},
> > +	{ "ccs3", I915_ENGINE_CLASS_COMPUTE, 3 , -1},
>
> LGTM,
>
> Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>

Is this correct? Isn't intel_execution_engines2 a list of just the legacy
engines? I don't think compute engines (which may vary in number) can be
added to the list of legacy engines. Isn't it true that compute engines can
only be accessed by querying the present engines dynamically (using
something like intel_ctx_create_all_physical())?

For example see:

/**
 * __for_each_static_engine:
 * @e__: struct intel_execution_engine2 iterator
 *
 * Iterates over each of the statically defined (legacy) engines.
 */
#define __for_each_static_engine(e__) \
        for ((e__) = intel_execution_engines2; (e__)->name[0]; (e__)++)