Quoting Tvrtko Ursulin (2018-10-02 10:05:11) > > On 01/10/2018 20:39, Chris Wilson wrote: > > Quoting Tvrtko Ursulin (2018-10-01 17:41:00) > >> > >> On 01/10/2018 17:24, Chris Wilson wrote: > >>> Quoting Tvrtko Ursulin (2018-10-01 17:15:24) > >>>> + len = sizeof(struct drm_i915_query_engine_info) + > >>>> + I915_NUM_ENGINES * sizeof(struct drm_i915_engine_info); > >>> > >>> Since I915_NUM_ENGINES is not ABI, and this will be using a 2-step > >>> query (1st to find length, 2nd to grab details), it should work with > >>> info->num_rings. If not, we have problems later ;) > >> > >> I don't follow, what do you plan to enumerate that would cause a problem? > > > > All I'm suggesting is to avoid any notion that this length is fixed > > indefinitely :) > > You mean extra paranoid step of making sure reported len exactly matches > the number of reported engines * sizeof(engine_info)? uAPI is defined to > query required memory block size and then read the reported num_engines > so I think that's fine, but sure, I can make it match exactly. No, my paranoia is towards people seeing I915_NUM_ENGINES and so assuming this is constant. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx