[gtk/fix-glx-slowness: 2/2] x11: Fix Vulkan slowness

[Matthias Clasen <matthiasc src gnome org>]

commit 56a9f15a0f6f6b1e3c06d50b3efb3966bbecbb8b
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Sep 10 21:15:05 2020 -0400

    x11: Fix Vulkan slowness
    
    Change our swapchain configuration from
    VK_PRESENT_MODE_FIFO_KHR to VK_PRESENT_MODE_IMMEDIATE_KHR.
    
    This makes second-long hangs in vkAcquireNextImageKHR() go
    away, which doesn't make any sense to me.

 gdk/gdkvulkancontext.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/gdkvulkancontext.c b/gdk/gdkvulkancontext.c
index 917b443f94..b1d345fd2b 100644
--- a/gdk/gdkvulkancontext.c
+++ b/gdk/gdkvulkancontext.c
@@ -354,7 +354,7 @@ gdk_vulkan_context_check_swapchain (GdkVulkanContext  *context,
                                                 },
                                                 .preTransform = capabilities.currentTransform,
                                                 .compositeAlpha = composite_alpha,
-                                                .presentMode = VK_PRESENT_MODE_FIFO_KHR,
+                                                .presentMode = VK_PRESENT_MODE_IMMEDIATE_KHR,
                                                 .clipped = VK_FALSE,
                                                 .oldSwapchain = priv->swapchain
                                             },