[ET-VK] Removing unnecessary and redundant members from VulkanBuffer and ParamsBuffer. (#7226)

Pull Request resolved: #7144

This diff removes unnecessary and redundant members from VulkanBuffer and ParamsBuffer.
ghstack-source-id: 256911526
@exported-using-ghexport

Differential Revision: [D66557456](https://our.internmc.facebook.com/intern/diff/D66557456/)

Co-authored-by: Vivek Trivedi <[email protected]>

Author: pytorchbot

backends/vulkan/runtime/api/containers/ParamsBuffer.h

@@ -20,7 +20,6 @@ namespace api {
 class ParamsBuffer final {
  private:
   Context* context_p_;
-  size_t nbytes_;
   vkapi::VulkanBuffer vulkan_buffer_;
 
  public:
@@ -29,14 +28,12 @@ class ParamsBuffer final {
   template <typename Block>
   ParamsBuffer(Context* context_p, const Block& block)
       : context_p_(context_p),
-        nbytes_(sizeof(block)),
         vulkan_buffer_(
             context_p_->adapter_ptr()->vma().create_params_buffer(block)) {}
 
   template <typename Block>
   ParamsBuffer(Context* context_p, const VkDeviceSize nbytes)
       : context_p_(context_p),
-        nbytes_(nbytes),
         vulkan_buffer_(
             context_p_->adapter_ptr()->vma().create_uniform_buffer(nbytes)) {}
 
@@ -70,7 +67,7 @@ class ParamsBuffer final {
   template <typename T>
   T read() const {
     T val;
-    if (sizeof(val) != nbytes_) {
+    if (sizeof(val) != vulkan_buffer_.mem_size()) {
       VK_THROW(
           "Attempted to store value from ParamsBuffer to type of different size");
     }

backends/vulkan/runtime/vk_api/memory/Buffer.cpp

@@ -29,12 +29,7 @@ VulkanBuffer::VulkanBuffer(
     const VmaAllocationCreateInfo& allocation_create_info,
     const VkBufferUsageFlags usage,
     const bool allocate_memory)
-    : buffer_properties_({
-          size,
-          0u,
-          size,
-          usage,
-      }),
+    : buffer_properties_({size, 0u, size}),
       allocator_(vma_allocator),
       memory_{},
       owns_memory_(allocate_memory),
@@ -52,7 +47,7 @@ VulkanBuffer::VulkanBuffer(
       nullptr, // pNext
       0u, // flags
       buffer_properties_.size, // size
-      buffer_properties_.buffer_usage, // usage
+      usage, // usage
       VK_SHARING_MODE_EXCLUSIVE, // sharingMode
       0u, // queueFamilyIndexCount
       nullptr, // pQueueFamilyIndices

backends/vulkan/runtime/vk_api/memory/Buffer.h

@@ -48,7 +48,6 @@ class VulkanBuffer final {
     VkDeviceSize size;
     VkDeviceSize mem_offset;
     VkDeviceSize mem_range;
-    VkBufferUsageFlags buffer_usage;
   };
 
   explicit VulkanBuffer();