From bf0dacbeb3265335a129ea3cb5172762d663a816 Mon Sep 17 00:00:00 2001
From: Jonah Williams <jonahwilliams@google.com>
Date: Tue, 5 Nov 2024 10:04:58 -0800
Subject: [PATCH] [Impeller] match Skia's old VMA default block size.
 (flutter/engine#56368)

The unspecified default is 256 MiB which is ... big. 4Mb value is the default that Skia used to use, and results in less memory usage at least in local testing.

benchmarks will determine if this has a positive or negative impact on performance.

https://github.com/flutter/flutter/issues/157497
---
 .../flutter/impeller/renderer/backend/vulkan/allocator_vk.cc   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/engine/src/flutter/impeller/renderer/backend/vulkan/allocator_vk.cc b/engine/src/flutter/impeller/renderer/backend/vulkan/allocator_vk.cc
index ae760a6e738..f66bbab100b 100644
--- a/engine/src/flutter/impeller/renderer/backend/vulkan/allocator_vk.cc
+++ b/engine/src/flutter/impeller/renderer/backend/vulkan/allocator_vk.cc
@@ -84,6 +84,7 @@ static PoolVMA CreateBufferPool(VmaAllocator allocator) {
   VmaPoolCreateInfo pool_create_info = {};
   pool_create_info.memoryTypeIndex = memTypeIndex;
   pool_create_info.flags = VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT;
+  pool_create_info.minBlockCount = 1;
 
   VmaPool pool = {};
   result = vk::Result{::vmaCreatePool(allocator, &pool_create_info, &pool)};
@@ -144,6 +145,8 @@ AllocatorVK::AllocatorVK(std::weak_ptr<Context> context,
   allocator_info.physicalDevice = physical_device;
   allocator_info.device = device_holder->GetDevice();
   allocator_info.instance = instance;
+  // 4 MB, matching the default used by Skia Vulkan.
+  allocator_info.preferredLargeHeapBlockSize = 4 * 1024 * 1024;
   allocator_info.pVulkanFunctions = &proc_table;
 
   VmaAllocator allocator = {};