From b678befb6ed055e6c66466505d9195a3cebf8073 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 1 Mar 2018 08:28:30 +0000 Subject: [PATCH] gl-renderer: Create a high priority context EGL_IMG_context_priority allows the client to request that their rendering be considered high priority. For ourselves, this is important as we are interactive and any delay in our rendering causes input-output jitter; a less than smooth user interactive. So if the driver supports setting the context priority, try and create our EGLContext as high priority. The driver may reject our request due to system restrictions, in which case it will fallback to normal priority, but if successful it will reschedule our rendering and all of its dependencies to execute earlier, especially important when the GPU is being hogged by background clients. Signed-off-by: Chris Wilson Reviewed-by: Daniel Stone Acked-by: Pekka Paalanen --- libweston/gl-renderer.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/libweston/gl-renderer.c b/libweston/gl-renderer.c index d3ed4a10..a6b29a92 100644 --- a/libweston/gl-renderer.c +++ b/libweston/gl-renderer.c @@ -223,6 +223,8 @@ struct gl_renderer { PFNEGLQUERYWAYLANDBUFFERWL query_buffer; int has_bind_display; + int has_context_priority; + int has_egl_image_external; int has_egl_buffer_age; @@ -3189,6 +3191,9 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec) return -1; } + if (weston_check_egl_extension(extensions, "EGL_IMG_context_priority")) + gr->has_context_priority = 1; + if (weston_check_egl_extension(extensions, "EGL_WL_bind_wayland_display")) gr->has_bind_display = 1; if (gr->has_bind_display) { @@ -3631,10 +3636,10 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface) EGLConfig context_config; EGLBoolean ret; - EGLint context_attribs[] = { + EGLint context_attribs[16] = { EGL_CONTEXT_CLIENT_VERSION, 0, - EGL_NONE }; + unsigned int nattr = 2; if (!eglBindAPI(EGL_OPENGL_ES_API)) { weston_log("failed to bind EGL_OPENGL_ES_API\n"); @@ -3642,6 +3647,21 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface) return -1; } + /* + * Being the compositor we require minimum output latency, + * so request a high priority context for ourselves - that should + * reschedule all of our rendering and its dependencies to be completed + * first. If the driver doesn't permit us to create a high priority + * context, it will fallback to the default priority (MEDIUM). + */ + if (gr->has_context_priority) { + context_attribs[nattr++] = EGL_CONTEXT_PRIORITY_LEVEL_IMG; + context_attribs[nattr++] = EGL_CONTEXT_PRIORITY_HIGH_IMG; + } + + assert(nattr < ARRAY_LENGTH(context_attribs)); + context_attribs[nattr] = EGL_NONE; + context_config = gr->egl_config; if (gr->has_configless_context) @@ -3665,6 +3685,18 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface) } } + if (gr->has_context_priority) { + EGLint value = EGL_CONTEXT_PRIORITY_MEDIUM_IMG; + + eglQueryContext(gr->egl_display, gr->egl_context, + EGL_CONTEXT_PRIORITY_LEVEL_IMG, &value); + + if (value != EGL_CONTEXT_PRIORITY_HIGH_IMG) { + weston_log("Failed to obtain a high priority context.\n"); + /* Not an error, continue on as normal */ + } + } + ret = eglMakeCurrent(gr->egl_display, egl_surface, egl_surface, gr->egl_context); if (ret == EGL_FALSE) {