[igt-dev] [PATCH i-g-t 05/21] wsim/media-bench: i915 balancing

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-05-08 13:10:42)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Support i915 virtual engine from gem_wsim (-b i915) and media-bench.pl
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
> +       /*
> +        * Create and configure contexts.
> +        */
> +       for (i = 0; i < wrk->nr_ctxs; i += 2) {
> +               struct ctx *ctx = &wrk->ctx_list[i];
> +               uint32_t ctx_id, share_vm = 0;
>  
> -                       wrk->ctx_list[w->context].id = arg.ctx_id;
> +               if (ctx->id)
> +                       continue;
>  
> -                       if (flags & GLOBAL_BALANCE) {
> -                               wrk->ctx_list[w->context].static_vcs = context_vcs_rr;
> -                               context_vcs_rr ^= 1;
> -                       } else {
> -                               wrk->ctx_list[w->context].static_vcs = ctx_vcs;
> -                               ctx_vcs ^= 1;
> -                       }
> +               if (flags & I915) {

vm sharing shouldn't be a i915-balancer only option. For single jobs split
across multiple contexts, I would expect they will want to share vm.

> +                       struct drm_i915_gem_context_create_ext_setparam ext = {
> +                               .base.name = I915_CONTEXT_CREATE_EXT_SETPARAM,
> +                               .param.param = I915_CONTEXT_PARAM_VM,
> +                       };
> +                       struct drm_i915_gem_context_create_ext args = { };
>  
> -                       if (wrk->prio) {
> +                       /* Find existing context to share ppgtt with. */
> +                       for (j = 0; j < wrk->nr_ctxs; j++) {
>                                 struct drm_i915_gem_context_param param = {
> -                                       .ctx_id = arg.ctx_id,
> -                                       .param = I915_CONTEXT_PARAM_PRIORITY,
> -                                       .value = wrk->prio,
> +                                       .param = I915_CONTEXT_PARAM_VM,
>                                 };
> -                               gem_context_set_param(fd, &param);
> +
> +                               if (!wrk->ctx_list[j].id)
> +                                       continue;
> +
> +                               param.ctx_id = wrk->ctx_list[j].id;
> +
> +                               gem_context_get_param(fd, &param);
> +                               igt_assert(param.value);
> +
> +                               share_vm = param.value;
> +
> +                               ext.param.value = share_vm;
> +                               args.flags =
> +                                   I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS;
> +                               args.extensions = to_user_pointer(&ext);
> +                               break;
>                         }
> +
> +                       if (!ctx->targets_instance)
> +                               args.flags |=
> +                                    I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE;
> +
> +                       drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE_EXT,
> +                                &args);
> +
> +                       ctx_id = args.ctx_id;
> +               } else {
> +                       struct drm_i915_gem_context_create args = {};
> +
> +                       drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &args);
> +                       ctx_id = args.ctx_id;
> +               }
> +
> +               igt_assert(ctx_id);
> +               ctx->id = ctx_id;
> +
> +               if (flags & GLOBAL_BALANCE) {
> +                       ctx->static_vcs = context_vcs_rr;
> +                       context_vcs_rr ^= 1;
> +               } else {
> +                       ctx->static_vcs = ctx_vcs;
> +                       ctx_vcs ^= 1;
> +               }
> +
> +               __ctx_set_prio(ctx_id, wrk->prio);
> +
> +               /*
> +                * Do we need a separate context to satisfy this workloads which
> +                * both want to target specific engines and be balanced by i915?
> +                */
> +               if ((flags & I915) && ctx->wants_balance &&
> +                   ctx->targets_instance) {
> +                       struct drm_i915_gem_context_create_ext_setparam ext = {
> +                               .base.name = I915_CONTEXT_CREATE_EXT_SETPARAM,
> +                               .param.param = I915_CONTEXT_PARAM_VM,
> +                               .param.value = share_vm,
> +                       };
> +                       struct drm_i915_gem_context_create_ext args = {
> +                               .extensions = to_user_pointer(&ext),
> +                               .flags =
> +                                   I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS |
> +                                   I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE,
> +                       };
> +
> +                       igt_assert(share_vm);
> +
> +                       drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE_EXT,
> +                                &args);
> +
> +                       igt_assert(args.ctx_id);
> +                       ctx_id = args.ctx_id;
> +                       wrk->ctx_list[i + 1].id = args.ctx_id;
> +
> +                       __ctx_set_prio(ctx_id, wrk->prio);
> +               }
> +
> +               if (ctx->wants_balance) {
> +                       I915_DEFINE_CONTEXT_ENGINES_LOAD_BALANCE(load_balance, 2) = {
> +                               .base.name = I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE,
> +                               .num_siblings = 2,
> +                               .engines = {
> +                                       { .engine_class = I915_ENGINE_CLASS_VIDEO,
> +                                         .engine_instance = 0 },
> +                                       { .engine_class = I915_ENGINE_CLASS_VIDEO,
> +                                         .engine_instance = 1 },
> +                               },
> +                       };
> +                       I915_DEFINE_CONTEXT_PARAM_ENGINES(set_engines, 3) = {
> +                               .extensions = to_user_pointer(&load_balance),
> +                               .engines = {
> +                                       { .engine_class = I915_ENGINE_CLASS_INVALID,
> +                                         .engine_instance = I915_ENGINE_CLASS_INVALID_NONE },
> +                                       { .engine_class = I915_ENGINE_CLASS_VIDEO,
> +                                         .engine_instance = 0 },
> +                                       { .engine_class = I915_ENGINE_CLASS_VIDEO,
> +                                         .engine_instance = 1 },
> +                               },
> +                       };
> +
> +                       struct drm_i915_gem_context_param param = {
> +                               .ctx_id = ctx_id,
> +                               .param = I915_CONTEXT_PARAM_ENGINES,
> +                               .size = sizeof(set_engines),
> +                               .value = to_user_pointer(&set_engines),
> +                       };
> +
> +                       gem_context_set_param(fd, &param);
>                 }

if (share_vm)
	gem_vm_destroy(share_vm);

Just to drop the local handle as the context has acquired its own
reference.

Other than that, it does what it sets out to do: create a context with
choice of engines and load balancing amongst them.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris