From d5db150801023c307fcbe1cd98b4fd8e2d27b55e Mon Sep 17 00:00:00 2001 From: Vito Caputo Date: Fri, 10 Jun 2022 20:11:23 -0700 Subject: til: introduce til_frame_plan_t and .cpu_affinity modules/checkers w/fill_module=$module requires a consistent mapping of cpu to fragnum since it creates a per-cpu til_module_context_t for the fill_module. The existing implementation for threaded rendering maximizes performance by letting *any* scheduled to run thread advance fragnum atomically and render the acquired fragnum indiscriminately. A side effect of this is any given frame, even rendered by the same module, will have a random mapping of cpus/threads to fragnums. With this change, the simple til_module_t.prepare_frame() API of returning a bare fragmenter function is changed to instead return a "frame plan" in til_frame_plan_t. Right now til_frame_plan_t just contains the same fragmenter as before, but also has a .cpu_affinity member for setting if the frame requires a stable relationship of cpu/thread to fragnum. Setting .cpu_affinity should be avoided if unnecessary, and that is the default if you don't mention .cpu_affinity at all when initializing the plan in the ergonomic manner w/designated initializers. This is because the way .cpu_affinity is implemented will leave threads spinning while they poll for *their* next fragnum using atomic intrinsics. There's probably some room for improvement here, but this is good enough for now to get things working and correct. --- src/modules/meta2d/meta2d.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/modules/meta2d') diff --git a/src/modules/meta2d/meta2d.c b/src/modules/meta2d/meta2d.c index c6a6c86..1ab444c 100644 --- a/src/modules/meta2d/meta2d.c +++ b/src/modules/meta2d/meta2d.c @@ -102,11 +102,11 @@ static void meta2d_destroy_context(til_module_context_t *context) } -static void meta2d_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t *fragment, til_fragmenter_t *res_fragmenter) +static void meta2d_prepare_frame(til_module_context_t *context, unsigned ticks, til_fb_fragment_t *fragment, til_frame_plan_t *res_frame_plan) { meta2d_context_t *ctxt = (meta2d_context_t *)context; - *res_fragmenter = til_fragmenter_slice_per_cpu; + *res_frame_plan = (til_frame_plan_t){ .fragmenter = til_fragmenter_slice_per_cpu }; /* move the balls around */ for (int i = 0; i < META2D_NUM_BALLS; i++) { -- cgit v1.2.3