dri: Optionally turn off a couple of GLX extensions based on driconf options

With GLX_EXT_buffer_age turned on, gnome-shell will use full-screen damage
with GLX, which severely hurts performance with architectures that emulate
page-flips with copies. Like vmware. We would like to be able to turn off that
extension. Similarly, typically the GLX_OML_sync_control doesn't make much
sense on a virtual architecture since we don't really sync to the host's
vertical retrace. We'd like to be able to turn it off as well.

Signed-off-by: Thomas Hellstrom <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 9 insertions, 2 deletions

diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
index 63474d0dca2..509160697f8 100644
--- a/src/glx/dri3_glx.c
+++ b/src/glx/dri3_glx.c
@@ -796,6 +796,7 @@ dri3_create_screen(int screen, struct glx_display * priv)
    struct glx_config *configs = NULL, *visuals = NULL;
    char *driverName, *deviceName, *tmp;
    int i;
+   unsigned char disable;
 
    psc = calloc(1, sizeof *psc);
    if (psc == NULL)
@@ -934,13 +935,19 @@ dri3_create_screen(int screen, struct glx_display * priv)
    psp->waitForSBC = dri3_wait_for_sbc;
    psp->setSwapInterval = dri3_set_swap_interval;
    psp->getSwapInterval = dri3_get_swap_interval;
-   __glXEnableDirectExtension(&psc->base, "GLX_OML_sync_control");
+   if (psc->config->configQueryb(psc->driScreen,
+                                 "glx_disable_oml_sync_control",
+                                 &disable) || !disable)
+      __glXEnableDirectExtension(&psc->base, "GLX_OML_sync_control");
 
    psp->copySubBuffer = dri3_copy_sub_buffer;
    __glXEnableDirectExtension(&psc->base, "GLX_MESA_copy_sub_buffer");
 
    psp->getBufferAge = dri3_get_buffer_age;
-   __glXEnableDirectExtension(&psc->base, "GLX_EXT_buffer_age");
+   if (psc->config->configQueryb(psc->driScreen,
+                                 "glx_disable_ext_buffer_age",
+                                 &disable) || !disable)
+      __glXEnableDirectExtension(&psc->base, "GLX_EXT_buffer_age");
 
    free(driverName);
    free(deviceName);