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Diffstat (limited to 'src/common/heap_tracker.cpp')
| -rw-r--r-- | src/common/heap_tracker.cpp | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/src/common/heap_tracker.cpp b/src/common/heap_tracker.cpp new file mode 100644 index 000000000..683208795 --- /dev/null +++ b/src/common/heap_tracker.cpp @@ -0,0 +1,281 @@ +// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <fstream> +#include <vector> + +#include "common/heap_tracker.h" +#include "common/logging/log.h" + +namespace Common { + +namespace { + +s64 GetMaxPermissibleResidentMapCount() { + // Default value. + s64 value = 65530; + + // Try to read how many mappings we can make. + std::ifstream s("/proc/sys/vm/max_map_count"); + s >> value; + + // Print, for debug. + LOG_INFO(HW_Memory, "Current maximum map count: {}", value); + + // Allow 20000 maps for other code and to account for split inaccuracy. + return std::max<s64>(value - 20000, 0); +} + +} // namespace + +HeapTracker::HeapTracker(Common::HostMemory& buffer) + : m_buffer(buffer), m_max_resident_map_count(GetMaxPermissibleResidentMapCount()) {} +HeapTracker::~HeapTracker() = default; + +void HeapTracker::Map(size_t virtual_offset, size_t host_offset, size_t length, + MemoryPermission perm, bool is_separate_heap) { + // When mapping other memory, map pages immediately. + if (!is_separate_heap) { + m_buffer.Map(virtual_offset, host_offset, length, perm, false); + return; + } + + { + // We are mapping part of a separate heap. + std::scoped_lock lk{m_lock}; + + auto* const map = new SeparateHeapMap{ + .vaddr = virtual_offset, + .paddr = host_offset, + .size = length, + .tick = m_tick++, + .perm = perm, + .is_resident = false, + }; + + // Insert into mappings. + m_map_count++; + m_mappings.insert(*map); + } + + // Finally, map. + this->DeferredMapSeparateHeap(virtual_offset); +} + +void HeapTracker::Unmap(size_t virtual_offset, size_t size, bool is_separate_heap) { + // If this is a separate heap... + if (is_separate_heap) { + std::scoped_lock lk{m_lock}; + + const SeparateHeapMap key{ + .vaddr = virtual_offset, + }; + + // Split at the boundaries of the region we are removing. + this->SplitHeapMapLocked(virtual_offset); + this->SplitHeapMapLocked(virtual_offset + size); + + // Erase all mappings in range. + auto it = m_mappings.find(key); + while (it != m_mappings.end() && it->vaddr < virtual_offset + size) { + // Get underlying item. + auto* const item = std::addressof(*it); + + // If resident, erase from resident map. + if (item->is_resident) { + ASSERT(--m_resident_map_count >= 0); + m_resident_mappings.erase(m_resident_mappings.iterator_to(*item)); + } + + // Erase from map. + ASSERT(--m_map_count >= 0); + it = m_mappings.erase(it); + + // Free the item. + delete item; + } + } + + // Unmap pages. + m_buffer.Unmap(virtual_offset, size, false); +} + +void HeapTracker::Protect(size_t virtual_offset, size_t size, MemoryPermission perm) { + // Ensure no rebuild occurs while reprotecting. + std::shared_lock lk{m_rebuild_lock}; + + // Split at the boundaries of the region we are reprotecting. + this->SplitHeapMap(virtual_offset, size); + + // Declare tracking variables. + const VAddr end = virtual_offset + size; + VAddr cur = virtual_offset; + + while (cur < end) { + VAddr next = cur; + bool should_protect = false; + + { + std::scoped_lock lk2{m_lock}; + + const SeparateHeapMap key{ + .vaddr = next, + }; + + // Try to get the next mapping corresponding to this address. + const auto it = m_mappings.nfind(key); + + if (it == m_mappings.end()) { + // There are no separate heap mappings remaining. + next = end; + should_protect = true; + } else if (it->vaddr == cur) { + // We are in range. + // Update permission bits. + it->perm = perm; + + // Determine next address and whether we should protect. + next = cur + it->size; + should_protect = it->is_resident; + } else /* if (it->vaddr > cur) */ { + // We weren't in range, but there is a block coming up that will be. + next = it->vaddr; + should_protect = true; + } + } + + // Clamp to end. + next = std::min(next, end); + + // Reprotect, if we need to. + if (should_protect) { + m_buffer.Protect(cur, next - cur, perm); + } + + // Advance. + cur = next; + } +} + +bool HeapTracker::DeferredMapSeparateHeap(u8* fault_address) { + if (m_buffer.IsInVirtualRange(fault_address)) { + return this->DeferredMapSeparateHeap(fault_address - m_buffer.VirtualBasePointer()); + } + + return false; +} + +bool HeapTracker::DeferredMapSeparateHeap(size_t virtual_offset) { + bool rebuild_required = false; + + { + std::scoped_lock lk{m_lock}; + + // Check to ensure this was a non-resident separate heap mapping. + const auto it = this->GetNearestHeapMapLocked(virtual_offset); + if (it == m_mappings.end() || it->is_resident) { + return false; + } + + // Update tick before possible rebuild. + it->tick = m_tick++; + + // Check if we need to rebuild. + if (m_resident_map_count > m_max_resident_map_count) { + rebuild_required = true; + } + + // Map the area. + m_buffer.Map(it->vaddr, it->paddr, it->size, it->perm, false); + + // This map is now resident. + it->is_resident = true; + m_resident_map_count++; + m_resident_mappings.insert(*it); + } + + if (rebuild_required) { + // A rebuild was required, so perform it now. + this->RebuildSeparateHeapAddressSpace(); + } + + return true; +} + +void HeapTracker::RebuildSeparateHeapAddressSpace() { + std::scoped_lock lk{m_rebuild_lock, m_lock}; + + ASSERT(!m_resident_mappings.empty()); + + // Dump half of the mappings. + // + // Despite being worse in theory, this has proven to be better in practice than more + // regularly dumping a smaller amount, because it significantly reduces average case + // lock contention. + const size_t desired_count = std::min(m_resident_map_count, m_max_resident_map_count) / 2; + const size_t evict_count = m_resident_map_count - desired_count; + auto it = m_resident_mappings.begin(); + + for (size_t i = 0; i < evict_count && it != m_resident_mappings.end(); i++) { + // Unmark and unmap. + it->is_resident = false; + m_buffer.Unmap(it->vaddr, it->size, false); + + // Advance. + ASSERT(--m_resident_map_count >= 0); + it = m_resident_mappings.erase(it); + } +} + +void HeapTracker::SplitHeapMap(VAddr offset, size_t size) { + std::scoped_lock lk{m_lock}; + + this->SplitHeapMapLocked(offset); + this->SplitHeapMapLocked(offset + size); +} + +void HeapTracker::SplitHeapMapLocked(VAddr offset) { + const auto it = this->GetNearestHeapMapLocked(offset); + if (it == m_mappings.end() || it->vaddr == offset) { + // Not contained or no split required. + return; + } + + // Cache the original values. + auto* const left = std::addressof(*it); + const size_t orig_size = left->size; + + // Adjust the left map. + const size_t left_size = offset - left->vaddr; + left->size = left_size; + + // Create the new right map. + auto* const right = new SeparateHeapMap{ + .vaddr = left->vaddr + left_size, + .paddr = left->paddr + left_size, + .size = orig_size - left_size, + .tick = left->tick, + .perm = left->perm, + .is_resident = left->is_resident, + }; + + // Insert the new right map. + m_map_count++; + m_mappings.insert(*right); + + // If resident, also insert into resident map. + if (right->is_resident) { + m_resident_map_count++; + m_resident_mappings.insert(*right); + } +} + +HeapTracker::AddrTree::iterator HeapTracker::GetNearestHeapMapLocked(VAddr offset) { + const SeparateHeapMap key{ + .vaddr = offset, + }; + + return m_mappings.find(key); +} + +} // namespace Common |