common: page_table: Update to use VirtualBuffer and simplify.

1 files changed, 9 insertions, 25 deletions

diff --git a/src/common/page_table.cpp b/src/common/page_table.cpp
index 566b57b62..e5d3090d5 100644
--- a/src/common/page_table.cpp
+++ b/src/common/page_table.cpp
@@ -6,36 +6,20 @@
 
 namespace Common {
 
-PageTable::PageTable(std::size_t page_size_in_bits) : page_size_in_bits{page_size_in_bits} {}
+PageTable::PageTable() = default;
 
 PageTable::~PageTable() = default;
 
-void PageTable::Resize(std::size_t address_space_width_in_bits) {
-    const std::size_t num_page_table_entries = 1ULL
-                                               << (address_space_width_in_bits - page_size_in_bits);
-
+void PageTable::Resize(std::size_t address_space_width_in_bits, std::size_t page_size_in_bits,
+                       bool has_attribute) {
+    const std::size_t num_page_table_entries{1ULL
+                                             << (address_space_width_in_bits - page_size_in_bits)};
     pointers.resize(num_page_table_entries);
-    attributes.resize(num_page_table_entries);
-
-    // The default is a 39-bit address space, which causes an initial 1GB allocation size. If the
-    // vector size is subsequently decreased (via resize), the vector might not automatically
-    // actually reallocate/resize its underlying allocation, which wastes up to ~800 MB for
-    // 36-bit titles. Call shrink_to_fit to reduce capacity to what's actually in use.
-
-    pointers.shrink_to_fit();
-    attributes.shrink_to_fit();
-}
-
-BackingPageTable::BackingPageTable(std::size_t page_size_in_bits) : PageTable{page_size_in_bits} {}
-
-BackingPageTable::~BackingPageTable() = default;
-
-void BackingPageTable::Resize(std::size_t address_space_width_in_bits) {
-    PageTable::Resize(address_space_width_in_bits);
-    const std::size_t num_page_table_entries = 1ULL
-                                               << (address_space_width_in_bits - page_size_in_bits);
     backing_addr.resize(num_page_table_entries);
-    backing_addr.shrink_to_fit();
+
+    if (has_attribute) {
+        attributes.resize(num_page_table_entries);
+    }
 }
 
 } // namespace Common