From 0cb9bc12fc80769676c48cb3fc173c4f46b7996e Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Sat, 29 Oct 2022 13:55:30 -0700
Subject: [PATCH] core: hle: kernel: k_page_heap: Refresh.
---
src/core/hle/kernel/k_page_heap.cpp | 86 ++++++++++++++++++++++++++++-
src/core/hle/kernel/k_page_heap.h | 39 ++++++++-----
2 files changed, 108 insertions(+), 17 deletions(-)
diff --git a/src/core/hle/kernel/k_page_heap.cpp b/src/core/hle/kernel/k_page_heap.cpp
index 5ede601686..7b02c7d8b8 100644
--- a/src/core/hle/kernel/k_page_heap.cpp
+++ b/src/core/hle/kernel/k_page_heap.cpp
@@ -44,11 +44,11 @@ size_t KPageHeap::GetNumFreePages() const {
return num_free;
}
-PAddr KPageHeap::AllocateBlock(s32 index, bool random) {
+PAddr KPageHeap::AllocateByLinearSearch(s32 index) {
const size_t needed_size = m_blocks[index].GetSize();
for (s32 i = index; i < static_cast<s32>(m_num_blocks); i++) {
- if (const PAddr addr = m_blocks[i].PopBlock(random); addr != 0) {
+ if (const PAddr addr = m_blocks[i].PopBlock(false); addr != 0) {
if (const size_t allocated_size = m_blocks[i].GetSize(); allocated_size > needed_size) {
this->Free(addr + needed_size, (allocated_size - needed_size) / PageSize);
}
@@ -59,6 +59,88 @@ PAddr KPageHeap::AllocateBlock(s32 index, bool random) {
return 0;
}
+PAddr KPageHeap::AllocateByRandom(s32 index, size_t num_pages, size_t align_pages) {
+ // Get the size and required alignment.
+ const size_t needed_size = num_pages * PageSize;
+ const size_t align_size = align_pages * PageSize;
+
+ // Determine meta-alignment of our desired alignment size.
+ const size_t align_shift = std::countr_zero(align_size);
+
+ // Decide on a block to allocate from.
+ constexpr size_t MinimumPossibleAlignmentsForRandomAllocation = 4;
+ {
+ // By default, we'll want to look at all blocks larger than our current one.
+ s32 max_blocks = static_cast<s32>(m_num_blocks);
+
+ // Determine the maximum block we should try to allocate from.
+ size_t possible_alignments = 0;
+ for (s32 i = index; i < max_blocks; ++i) {
+ // Add the possible alignments from blocks at the current size.
+ possible_alignments += (1 + ((m_blocks[i].GetSize() - needed_size) >> align_shift)) *
+ m_blocks[i].GetNumFreeBlocks();
+
+ // If there are enough possible alignments, we don't need to look at larger blocks.
+ if (possible_alignments >= MinimumPossibleAlignmentsForRandomAllocation) {
+ max_blocks = i + 1;
+ break;
+ }
+ }
+
+ // If we have any possible alignments which require a larger block, we need to pick one.
+ if (possible_alignments > 0 && index + 1 < max_blocks) {
+ // Select a random alignment from the possibilities.
+ const size_t rnd = m_rng.GenerateRandom(possible_alignments);
+
+ // Determine which block corresponds to the random alignment we chose.
+ possible_alignments = 0;
+ for (s32 i = index; i < max_blocks; ++i) {
+ // Add the possible alignments from blocks at the current size.
+ possible_alignments +=
+ (1 + ((m_blocks[i].GetSize() - needed_size) >> align_shift)) *
+ m_blocks[i].GetNumFreeBlocks();
+
+ // If the current block gets us to our random choice, use the current block.
+ if (rnd < possible_alignments) {
+ index = i;
+ break;
+ }
+ }
+ }
+ }
+
+ // Pop a block from the index we selected.
+ if (PAddr addr = m_blocks[index].PopBlock(true); addr != 0) {
+ // Determine how much size we have left over.
+ if (const size_t leftover_size = m_blocks[index].GetSize() - needed_size;
+ leftover_size > 0) {
+ // Determine how many valid alignments we can have.
+ const size_t possible_alignments = 1 + (leftover_size >> align_shift);
+
+ // Select a random valid alignment.
+ const size_t random_offset = m_rng.GenerateRandom(possible_alignments) << align_shift;
+
+ // Free memory before the random offset.
+ if (random_offset != 0) {
+ this->Free(addr, random_offset / PageSize);
+ }
+
+ // Advance our block by the random offset.
+ addr += random_offset;
+
+ // Free memory after our allocated block.
+ if (random_offset != leftover_size) {
+ this->Free(addr + needed_size, (leftover_size - random_offset) / PageSize);
+ }
+ }
+
+ // Return the block we allocated.
+ return addr;
+ }
+
+ return 0;
+}
+
void KPageHeap::FreeBlock(PAddr block, s32 index) {
do {
block = m_blocks[index++].PushBlock(block);
diff --git a/src/core/hle/kernel/k_page_heap.h b/src/core/hle/kernel/k_page_heap.h
index 0917a8bed9..9021edcf7b 100644
--- a/src/core/hle/kernel/k_page_heap.h
+++ b/src/core/hle/kernel/k_page_heap.h
@@ -14,13 +14,9 @@
namespace Kernel {
-class KPageHeap final {
+class KPageHeap {
public:
- YUZU_NON_COPYABLE(KPageHeap);
- YUZU_NON_MOVEABLE(KPageHeap);
-
KPageHeap() = default;
- ~KPageHeap() = default;
constexpr PAddr GetAddress() const {
return m_heap_address;
@@ -57,7 +53,20 @@ public:
m_initial_used_size = m_heap_size - free_size - reserved_size;
}
- PAddr AllocateBlock(s32 index, bool random);
+ PAddr AllocateBlock(s32 index, bool random) {
+ if (random) {
+ const size_t block_pages = m_blocks[index].GetNumPages();
+ return this->AllocateByRandom(index, block_pages, block_pages);
+ } else {
+ return this->AllocateByLinearSearch(index);
+ }
+ }
+
+ PAddr AllocateAligned(s32 index, size_t num_pages, size_t align_pages) {
+ // TODO: linear search support?
+ return this->AllocateByRandom(index, num_pages, align_pages);
+ }
+
void Free(PAddr addr, size_t num_pages);
static size_t CalculateManagementOverheadSize(size_t region_size) {
@@ -68,7 +77,7 @@ public:
static constexpr s32 GetAlignedBlockIndex(size_t num_pages, size_t align_pages) {
const size_t target_pages = std::max(num_pages, align_pages);
for (size_t i = 0; i < NumMemoryBlockPageShifts; i++) {
- if (target_pages <= (size_t(1) << MemoryBlockPageShifts[i]) / PageSize) {
+ if (target_pages <= (static_cast<size_t>(1) << MemoryBlockPageShifts[i]) / PageSize) {
return static_cast<s32>(i);
}
}
@@ -77,7 +86,7 @@ public:
static constexpr s32 GetBlockIndex(size_t num_pages) {
for (s32 i = static_cast<s32>(NumMemoryBlockPageShifts) - 1; i >= 0; i--) {
- if (num_pages >= (size_t(1) << MemoryBlockPageShifts[i]) / PageSize) {
+ if (num_pages >= (static_cast<size_t>(1) << MemoryBlockPageShifts[i]) / PageSize) {
return i;
}
}
@@ -85,7 +94,7 @@ public:
}
static constexpr size_t GetBlockSize(size_t index) {
- return size_t(1) << MemoryBlockPageShifts[index];
+ return static_cast<size_t>(1) << MemoryBlockPageShifts[index];
}
static constexpr size_t GetBlockNumPages(size_t index) {
@@ -93,13 +102,9 @@ public:
}
private:
- class Block final {
+ class Block {
public:
- YUZU_NON_COPYABLE(Block);
- YUZU_NON_MOVEABLE(Block);
-
Block() = default;
- ~Block() = default;
constexpr size_t GetShift() const {
return m_block_shift;
@@ -201,6 +206,9 @@ private:
};
private:
+ PAddr AllocateByLinearSearch(s32 index);
+ PAddr AllocateByRandom(s32 index, size_t num_pages, size_t align_pages);
+
static size_t CalculateManagementOverheadSize(size_t region_size, const size_t* block_shifts,
size_t num_block_shifts);
@@ -209,7 +217,8 @@ private:
size_t m_heap_size{};
size_t m_initial_used_size{};
size_t m_num_blocks{};
- std::array<Block, NumMemoryBlockPageShifts> m_blocks{};
+ std::array<Block, NumMemoryBlockPageShifts> m_blocks;
+ KPageBitmap::RandomBitGenerator m_rng;
std::vector<u64> m_management_data;
};