[igt-dev] [PATCH i-g-t 14/21] gem_wsim: Engine map load balance command

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-05-08 13:10:51)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> A new workload command for enabling a load balanced context map (aka
> Virtual Engine). Example usage:
> 
>   B.1
> 
> This turns on load balancing for context one, assuming it has already been
> configured with an engine map. Only DEFAULT engine specifier can be used
> with load balanced engine maps.

Restriction makes sense for keeping linenoise^W file format simple.

> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
> @@ -1172,6 +1210,8 @@ prepare_workload(unsigned int id, struct workload *wrk, unsigned int flags)
>                 if (ctx->engine_map) {
>                         I915_DEFINE_CONTEXT_PARAM_ENGINES(set_engines,
>                                                           ctx->engine_map_count + 1);
> +                       I915_DEFINE_CONTEXT_ENGINES_LOAD_BALANCE(load_balance,
> +                                                                ctx->engine_map_count);
>                         struct drm_i915_gem_context_param param = {
>                                 .ctx_id = ctx_id,
>                                 .param = I915_CONTEXT_PARAM_ENGINES,
> @@ -1179,7 +1219,25 @@ prepare_workload(unsigned int id, struct workload *wrk, unsigned int flags)
>                                 .value = to_user_pointer(&set_engines),
>                         };
>  
> -                       set_engines.extensions = 0;
> +                       if (ctx->wants_balance) {
> +                               set_engines.extensions =
> +                                       to_user_pointer(&load_balance);
> +
> +                               memset(&load_balance, 0, sizeof(load_balance));
> +                               load_balance.base.name =
> +                                       I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE;
> +                               load_balance.num_siblings =
> +                                       ctx->engine_map_count;
> +
> +                               for (j = 0; j < ctx->engine_map_count; j++) {
> +                                       load_balance.engines[j].engine_class =
> +                                               I915_ENGINE_CLASS_VIDEO; /* FIXME */
> +                                       load_balance.engines[j].engine_instance =
> +                                               ctx->engine_map[j] - VCS1; /* FIXME */

Ok, more fallout from fixing ctx->engine_map[] first?

Otherwise looks fine.
-Chris