vulkan: keep the stream buffer within a small iGPU heap

The stream buffer prefers device-local host-visible memory. On a Radeon
780M that is a 256 MiB heap with a 243 MiB budget, and the 256 MiB
buffer alone kept it over budget for the whole session ("VMA heap 2:
usage 256 MiB of budget 243 MiB"). On integrated GPUs whose
device-local host-visible heap is no bigger than the stream buffer, use
three quarters of the heap instead (192 MiB there).

Radeon 780M, Mario Kart World title screen: heap 2 at 192 of 243 MiB,
picture and frame rate unchanged.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/video_core/vulkan_common/vulkan_device.h b/src/video_core/vulkan_common/vulkan_device.h
index d8524f6575..eb7cb15dc8 100644
--- a/src/video_core/vulkan_common/vulkan_device.h
+++ b/src/video_core/vulkan_common/vulkan_device.h
@@ -928,6 +928,11 @@ FN_MAX_LIMIT_LIST
         return 0x00010300U;
     }
 
+    /// Returns true for an integrated GPU (its device-local memory is system memory).
+    bool IsIntegrated() const {
+        return is_integrated;
+    }
+
     /// Returns true when a known debugging tool is attached.
     bool HasDebuggingToolAttached() const {
         return has_renderdoc || has_nsight_graphics || has_radeon_gpu_profiler;