From 26381fd5df976cc20ab5a5ffc55143067e1e4972 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Sat, 12 Feb 2022 14:34:54 +0100
Subject: [PATCH] [d3d11] Only use updateBuffer for very small buffer updates

Otherwise we may end up with significant copy overhead on the CS thread.
---
 src/d3d11/d3d11_context.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/d3d11/d3d11_context.cpp b/src/d3d11/d3d11_context.cpp
index 3171db31..cc470eee 100644
--- a/src/d3d11/d3d11_context.cpp
+++ b/src/d3d11/d3d11_context.cpp
@@ -3572,8 +3572,9 @@ namespace dxvk {
     const void*                             pSrcData) {
     DxvkBufferSlice bufferSlice = pDstBuffer->GetBufferSlice(Offset, Length);
 
-    if (Length <= 65536) {
-      // The backend has special code paths for small buffer updates
+    if (Length <= 1024 && !(Offset & 0x3) && !(Length & 0x3)) {
+      // The backend has special code paths for small buffer updates,
+      // however both offset and size must be aligned to four bytes.
       DxvkDataSlice dataSlice = AllocUpdateBufferSlice(Length);
       std::memcpy(dataSlice.ptr(), pSrcData, Length);