On Wed, Oct 3, 2018 at 4:16 AM Eero Tamminen <eero.t.tammi...@intel.com> wrote: > > Hi, > > On 10/3/18 2:00 AM, Marek Olšák wrote: > > On Tue, Oct 2, 2018 at 6:36 PM Rob Clark <robdcl...@gmail.com> wrote: > >> On Tue, Oct 2, 2018 at 6:30 PM Marek Olšák <mar...@gmail.com> wrote: > >>> From: Marek Olšák <marek.ol...@amd.com> > [...] > >> Just curious (and maybe I missed some previous discussion), would this > >> override taskset? > >> > >> Asking because when benchmarking on big/little arm SoCs I tend to use > >> taskset to pin things to either the fast cores or slow cores, to > >> eliminate a source of uncertainty in the result. (And I use u_queue > >> to split of the 2nd half of batch submits, Ie. the part that generates > >> gmem/tiling cmds and does the kernel submit ioctl). Would be slightly > >> annoying to loose that ability to control which group of cores the > >> u_queue thread runs on. > >> > >> (But admittedly this is kind of an edge case, so I guess an env var to > >> override the behavior would be ok.) > > > > I don't know, but I guess it affects it. > > > > pipe_context::set_context_param(ctx, > > PIPE_CONTEXT_PARAM_PIN_THREADS_TO_L3_CACHE, L3_group_index); is > > similar to what you need. > > > > The ideal option would be to have such default behavior on ARM that is > > the most desirable. An env var is the second option. > > Use of taskset is not ARM specific. I've seen nasty kernel scheduler > CPU core bouncing issues also on other platforms. Debugging those > required using taskset for the given game. > > Also, to get any kind of reliable CPU utilization figure, one also needs > to bind task to a specific core (or build a kernel with freq stats > support, which isn't enabled by default in any distro kernels, and have > suitable tooling to parse that data). > > So, which games use thread affinity for threads that use Mesa, and how > much that is a problem, i.e. why this patch is needed?
The Mesa code for Ryzen sets thread affinity. Queues and threads created later need to undo it. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
