radv: adjust the CmdUpdateBuffer threshold for optimal performance

According to my benchmark results, it appears that we should
reduce the threshold to 1024.

BEFORE:
1 KB: 68.656000 ms
2 KB: 118.368000 ms

AFTER:
1 KB: 31.760000 ms
2 KB: 29.840000 ms

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/vulkan/radv_meta_buffer.c

@@ -513,7 +513,7 @@ void radv_CmdUpdateBuffer(
 	if (!dataSize)
 		return;
 
-	if (dataSize < RADV_BUFFER_OPS_CS_THRESHOLD) {
+	if (dataSize < RADV_BUFFER_UPDATE_THRESHOLD) {
 		si_emit_cache_flush(cmd_buffer);
 
 		radv_cs_add_buffer(cmd_buffer->device->ws, cmd_buffer->cs, dst_buffer->bo);

src/amd/vulkan/radv_private.h

@@ -108,6 +108,8 @@ typedef uint32_t xcb_window_t;
  */
 #define RADV_BUFFER_OPS_CS_THRESHOLD 4096
 
+#define RADV_BUFFER_UPDATE_THRESHOLD 1024
+
 enum radv_mem_heap {
 	RADV_MEM_HEAP_VRAM,
 	RADV_MEM_HEAP_VRAM_CPU_ACCESS,