diff --git a/Core/Debugger/MemBlockInfo.cpp b/Core/Debugger/MemBlockInfo.cpp
index 09c5d2749e..14180ec046 100644
--- a/Core/Debugger/MemBlockInfo.cpp
+++ b/Core/Debugger/MemBlockInfo.cpp
@@ -15,20 +15,290 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#include "Common/Log.h"
+#include "Common/Serialize/Serializer.h"
+#include "Common/Serialize/SerializeFuncs.h"
 #include "Core/Debugger/Breakpoints.h"
 #include "Core/Debugger/MemBlockInfo.h"
 #include "Core/MIPS/MIPS.h"
 
+class MemSlabMap {
+public:
+	MemSlabMap();
+	~MemSlabMap();
+
+	bool Mark(uint32_t addr, uint32_t size, uint32_t pc, bool allocated, const std::string &tag);
+	bool Find(MemBlockFlags flags, uint32_t addr, uint32_t size, std::vector<MemBlockInfo> &results);
+	void Reset();
+	void DoState(PointerWrap &p);
+
+private:
+	struct Slab {
+		uint32_t start;
+		uint32_t size;
+		uint32_t pc;
+		bool allocated;
+		std::string tag;
+		Slab *prev;
+		Slab *next;
+
+		void DoState(PointerWrap &p);
+	};
+
+	Slab *FindSlab(uint32_t addr);
+	void Clear();
+	// Returns the new slab after size.
+	Slab *Split(Slab *slab, uint32_t size);
+	void MergeAdjacent(Slab *slab);
+	bool Same(const Slab *a, const Slab *b) const;
+	void Merge(Slab *a, Slab *b);
+
+	Slab *first_ = nullptr;
+};
+
+static MemSlabMap allocMap;
+static MemSlabMap suballocMap;
+static MemSlabMap writeMap;
+
+MemSlabMap::MemSlabMap() {
+	Reset();
+}
+
+MemSlabMap::~MemSlabMap() {
+	Clear();
+}
+
+bool MemSlabMap::Mark(uint32_t addr, uint32_t size, uint32_t pc, bool allocated, const std::string &tag) {
+	uint32_t end = addr + size;
+	Slab *slab = FindSlab(addr);
+	Slab *firstMatch = nullptr;
+	while (slab != nullptr && slab->start < end) {
+		if (slab->start < addr)
+			slab = Split(slab, addr - slab->start);
+		// Don't replace slab, the return is the after part.
+		if (slab->start + slab->size > end) {
+			Split(slab, end - slab->start);
+		}
+
+		slab->allocated = allocated;
+		if (pc != 0)
+			slab->pc = pc;
+		if (!tag.empty())
+			slab->tag = tag;
+
+		// Move on to the next one.
+		if (firstMatch != nullptr)
+			firstMatch = slab;
+		slab = slab->next;
+	}
+
+	if (firstMatch != nullptr) {
+		// This will merge all those blocks to one.
+		MergeAdjacent(firstMatch);
+		return true;
+	}
+	return false;
+}
+
+bool MemSlabMap::Find(MemBlockFlags flags, uint32_t addr, uint32_t size, std::vector<MemBlockInfo> &results) {
+	uint32_t end = addr + size;
+	Slab *slab = FindSlab(addr);
+	bool found = false;
+	while (slab != nullptr && slab->start < end) {
+		results.push_back({ flags, slab->start, slab->size, slab->pc, slab->tag, slab->allocated });
+		found = true;
+		slab = slab->next;
+	}
+	return found;
+}
+
+void MemSlabMap::Reset() {
+	Clear();
+
+	first_ = new Slab{ 0, UINT_MAX, 0, false, "", nullptr, nullptr };
+}
+
+void MemSlabMap::DoState(PointerWrap &p) {
+	auto s = p.Section("MemSlabMap", 1);
+	if (!s)
+		return;
+
+	int count = 0;
+	if (p.mode == p.MODE_READ) {
+		Clear();
+		Do(p, count);
+
+		first_ = new Slab();
+		first_->DoState(p);
+		first_->prev = nullptr;
+		first_->next = nullptr;
+		--count;
+
+		Slab *slab = first_;
+		for (int i = 0; i < count; ++i) {
+			slab->next = new Slab();
+			slab->DoState(p);
+
+			slab->next->prev = slab;
+			slab = slab->next;
+		}
+	} else {
+		for (Slab *slab = first_; slab != nullptr; slab = slab->next)
+			++count;
+		Do(p, count);
+
+		first_->DoState(p);
+		--count;
+
+		Slab *slab = first_;
+		for (int i = 0; i < count; ++i) {
+			slab->next->DoState(p);
+			slab = slab->next;
+		}
+	}
+}
+
+void MemSlabMap::Slab::DoState(PointerWrap &p) {
+	auto s = p.Section("MemSlabMapSlab", 1);
+	if (!s)
+		return;
+
+	Do(p, start);
+	Do(p, size);
+	Do(p, pc);
+	Do(p, allocated);
+	Do(p, tag);
+}
+
+void MemSlabMap::Clear() {
+	Slab *s = first_;
+	while (s != nullptr) {
+		Slab *next = s->next;
+		delete s;
+		s = next;
+	}
+	first_ = nullptr;
+}
+
+MemSlabMap::Slab *MemSlabMap::FindSlab(uint32_t addr) {
+	Slab *slab = first_;
+	while (slab != nullptr && slab->start <= addr) {
+		if (slab->start + slab->size > addr)
+			return slab;
+		slab = slab->next;
+	}
+	return nullptr;
+}
+
+MemSlabMap::Slab *MemSlabMap::Split(Slab *slab, uint32_t size) {
+	uint32_t nextStart = slab->start + size;
+	uint32_t nextSize = slab->size - size;
+	Slab *next = new Slab{ nextStart, nextSize, slab->pc, slab->allocated, slab->tag, slab, slab->next };
+	slab->next = next;
+	if (next->next)
+		next->next->prev = next;
+
+	slab->size = size;
+	return next;
+}
+
+void MemSlabMap::MergeAdjacent(Slab *slab) {
+	while (slab->next != nullptr && Same(slab, slab->next)) {
+		Merge(slab, slab->next);
+	}
+	while (slab->prev != nullptr && Same(slab, slab->prev)) {
+		Merge(slab, slab->prev);
+	}
+}
+
+bool MemSlabMap::Same(const Slab *a, const Slab *b) const {
+	if (a->allocated != b->allocated)
+		return false;
+	if (a->pc != b->pc)
+		return false;
+	if (a->tag != b->tag)
+		return false;
+	return true;
+}
+
+void MemSlabMap::Merge(Slab *a, Slab *b) {
+	if (a->next == b) {
+		_assert_(a->start + a->size == b->start);
+		a->next = b->next;
+
+		if (a->next)
+			a->next->prev = a;
+	} else if (a->prev == b) {
+		_assert_(b->start + b->size == a->start);
+		a->start = b->start;
+		a->prev = b->prev;
+
+		if (a->prev)
+			a->prev->next = a;
+		else if (first_ == b)
+			first_ = a;
+	} else {
+		_assert_(false);
+	}
+	a->size += b->size;
+	delete b;
+}
+
 void NotifyMemInfo(MemBlockFlags flags, uint32_t start, uint32_t size, const std::string &tag) {
 	NotifyMemInfoPC(flags, start, size, currentMIPS->pc, tag);
 }
 
 void NotifyMemInfoPC(MemBlockFlags flags, uint32_t start, uint32_t size, uint32_t pc, const std::string &tag) {
-	// TODO
+	if (size == 0) {
+		return;
+	}
+	// Clear the uncached and kernel bits.
+	start &= ~0xC0000000;
 
+	if (flags & MemBlockFlags::ALLOC) {
+		allocMap.Mark(start, size, pc, true, tag);
+	} else if (flags & MemBlockFlags::FREE) {
+		// Maintain the previous allocation tag for debugging.
+		allocMap.Mark(start, size, 0, false, "");
+		suballocMap.Mark(start, size, 0, false, "");
+	}
+	if (flags & MemBlockFlags::SUB_ALLOC) {
+		suballocMap.Mark(start, size, pc, true, tag);
+	} else if (flags & MemBlockFlags::SUB_FREE) {
+		// Maintain the previous allocation tag for debugging.
+		suballocMap.Mark(start, size, 0, false, "");
+	}
 	if (flags & MemBlockFlags::WRITE) {
 		CBreakPoints::ExecMemCheck(start, true, size, pc, tag);
+		writeMap.Mark(start, size, pc, true, tag);
 	} else if (flags & MemBlockFlags::READ) {
 		CBreakPoints::ExecMemCheck(start, false, size, pc, tag);
 	}
 }
+
+std::vector<MemBlockInfo> FindMemInfo(uint32_t start, uint32_t size) {
+	std::vector<MemBlockInfo> results;
+	allocMap.Find(MemBlockFlags::ALLOC, start, size, results);
+	suballocMap.Find(MemBlockFlags::SUB_ALLOC, start, size, results);
+	writeMap.Find(MemBlockFlags::WRITE, start, size, results);
+	return results;
+}
+
+void MemBlockInfoInit() {
+}
+
+void MemBlockInfoShutdown() {
+	allocMap.Reset();
+	suballocMap.Reset();
+	writeMap.Reset();
+}
+
+void MemBlockInfoDoState(PointerWrap &p) {
+	auto s = p.Section("MemBlockInfo", 0, 1);
+	if (!s)
+		return;
+
+	allocMap.DoState(p);
+	suballocMap.DoState(p);
+	writeMap.DoState(p);
+}
diff --git a/Core/Debugger/MemBlockInfo.h b/Core/Debugger/MemBlockInfo.h
index a150b2f272..573b6701f5 100644
--- a/Core/Debugger/MemBlockInfo.h
+++ b/Core/Debugger/MemBlockInfo.h
@@ -19,18 +19,36 @@
 
 #include <cstdint>
 #include <string>
+#include <vector>
 #include "Common/Common.h"
 
+class PointerWrap;
+
 enum class MemBlockFlags {
-	FREE = 0,
 	ALLOC = 1,
 	SUB_ALLOC = 2,
 	WRITE = 4,
 	// Not actually logged.
 	READ = 8,
-	SUB_FREE = 16,
+	FREE = 16,
+	SUB_FREE = 32,
 };
 ENUM_CLASS_BITOPS(MemBlockFlags);
 
+struct MemBlockInfo {
+	MemBlockFlags flags;
+	uint32_t start;
+	uint32_t size;
+	uint32_t pc;
+	std::string tag;
+	bool allocated;
+};
+
 void NotifyMemInfo(MemBlockFlags flags, uint32_t start, uint32_t size, const std::string &tag);
 void NotifyMemInfoPC(MemBlockFlags flags, uint32_t start, uint32_t size, uint32_t pc, const std::string &tag);
+
+std::vector<MemBlockInfo> FindMemInfo(uint32_t start, uint32_t size);
+
+void MemBlockInfoInit();
+void MemBlockInfoShutdown();
+void MemBlockInfoDoState(PointerWrap &p);
diff --git a/Core/HLE/sceKernelMemory.cpp b/Core/HLE/sceKernelMemory.cpp
index 50439e5d2b..7358dd3ffc 100644
--- a/Core/HLE/sceKernelMemory.cpp
+++ b/Core/HLE/sceKernelMemory.cpp
@@ -427,6 +427,7 @@ void __KernelFplEndCallback(SceUID threadID, SceUID prevCallbackId);
 
 void __KernelMemoryInit()
 {
+	MemBlockInfoInit();
 	kernelMemory.Init(PSP_GetKernelMemoryBase(), PSP_GetKernelMemoryEnd() - PSP_GetKernelMemoryBase(), false);
 	userMemory.Init(PSP_GetUserMemoryBase(), PSP_GetUserMemoryEnd() - PSP_GetUserMemoryBase(), false);
 	Memory::Memset(PSP_GetKernelMemoryBase(), 0, PSP_GetKernelMemoryEnd() - PSP_GetKernelMemoryBase());
@@ -472,6 +473,8 @@ void __KernelMemoryDoState(PointerWrap &p)
 	if (s >= 2) {
 		Do(p, tlsplThreadEndChecks);
 	}
+
+	MemBlockInfoDoState(p);
 }
 
 void __KernelMemoryShutdown()
@@ -487,6 +490,7 @@ void __KernelMemoryShutdown()
 #endif
 	kernelMemory.Shutdown();
 	tlsplThreadEndChecks.clear();
+	MemBlockInfoShutdown();
 }
 
 enum SceKernelFplAttr