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5d491fa1cd
This is a freelist allocator with static size classes that works as a complement to the generic kmalloc(). It's a lot faster than kmalloc() since allocation just means popping from the freelist. It's also significantly more compact when there are a lot of objects smaller than the minimum kmalloc chunk size (32 bytes.) This patch enables it for the Region and PhysicalPage classes. In the PhysicalPage (8 bytes) case, it's a huge improvement since we no longer waste 75% of the storage allocated. There are also a number of ways this can be improved, so let's keep working on it going forward.
48 lines
1.1 KiB
C++
48 lines
1.1 KiB
C++
#pragma once
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#include <AK/NonnullRefPtr.h>
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#include <Kernel/Assertions.h>
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#include <Kernel/Heap/SlabAllocator.h>
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#include <Kernel/VM/PhysicalAddress.h>
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class PhysicalPage {
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friend class MemoryManager;
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friend class PageDirectory;
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friend class VMObject;
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MAKE_SLAB_ALLOCATED(PhysicalPage)
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public:
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PhysicalAddress paddr() const { return m_paddr; }
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void ref()
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{
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ASSERT(m_retain_count);
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++m_retain_count;
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}
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void deref()
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{
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ASSERT(m_retain_count);
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if (!--m_retain_count) {
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if (m_may_return_to_freelist)
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move(*this).return_to_freelist();
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delete this;
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}
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}
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static NonnullRefPtr<PhysicalPage> create(PhysicalAddress, bool supervisor, bool may_return_to_freelist = true);
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u16 ref_count() const { return m_retain_count; }
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private:
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PhysicalPage(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist = true);
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~PhysicalPage() {}
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void return_to_freelist() &&;
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u16 m_retain_count { 1 };
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bool m_may_return_to_freelist { true };
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bool m_supervisor { false };
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PhysicalAddress m_paddr;
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};
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