PageTable: move backing addresses to a children class as the CPU page table does not need them.

This PR aims to reduce the memory usage in the CPU page table by moving
GPU specific parameters into a child class. This saves 1Gb of Memory for
most games.
This commit is contained in:
Fernando Sahmkow 2020-03-13 16:33:47 -04:00 committed by FernandoS27
parent b30b1f741d
commit 27cbb75e7c
3 changed files with 25 additions and 4 deletions

View file

@ -16,7 +16,6 @@ void PageTable::Resize(std::size_t address_space_width_in_bits) {
pointers.resize(num_page_table_entries); pointers.resize(num_page_table_entries);
attributes.resize(num_page_table_entries); attributes.resize(num_page_table_entries);
backing_addr.resize(num_page_table_entries);
// The default is a 39-bit address space, which causes an initial 1GB allocation size. If the // 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 // vector size is subsequently decreased (via resize), the vector might not automatically
@ -25,6 +24,17 @@ void PageTable::Resize(std::size_t address_space_width_in_bits) {
pointers.shrink_to_fit(); pointers.shrink_to_fit();
attributes.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(); backing_addr.shrink_to_fit();
} }

View file

@ -76,9 +76,20 @@ struct PageTable {
*/ */
std::vector<PageType> attributes; std::vector<PageType> attributes;
std::vector<u64> backing_addr;
const std::size_t page_size_in_bits{}; const std::size_t page_size_in_bits{};
}; };
/**
* A more advanced Page Table with the ability to save a backing address when using it
* depends on another MMU.
*/
struct BackingPageTable : PageTable {
explicit BackingPageTable(std::size_t page_size_in_bits);
~BackingPageTable();
void Resize(std::size_t address_space_width_in_bits);
std::vector<u64> backing_addr;
};
} // namespace Common } // namespace Common

View file

@ -174,7 +174,7 @@ private:
/// End of address space, based on address space in bits. /// End of address space, based on address space in bits.
static constexpr GPUVAddr address_space_end{1ULL << address_space_width}; static constexpr GPUVAddr address_space_end{1ULL << address_space_width};
Common::PageTable page_table{page_bits}; Common::BackingPageTable page_table{page_bits};
VMAMap vma_map; VMAMap vma_map;
VideoCore::RasterizerInterface& rasterizer; VideoCore::RasterizerInterface& rasterizer;