diff --git a/uppsrc/CodeEditor/CInit.cpp b/uppsrc/CodeEditor/CInit.cpp
index 31f1b57e3..cd682f0d0 100644
--- a/uppsrc/CodeEditor/CInit.cpp
+++ b/uppsrc/CodeEditor/CInit.cpp
@@ -41,7 +41,7 @@ void CSyntax::InitKeywords()
 		"do", "__int64", "static", "volatile",
 		"double", "__leave", "static_cast",
 		"dynamic_cast", "long", "__stdcall", "while",
-		"force_inline",
+		"force_inline", "never_inline",
 		"and", "bitor", "or", "xor",
 		"compl", "bitand", "and_eq", "or_eq",
 		"xor_eq", "not", "not_eq",
diff --git a/uppsrc/Core/Heap.h b/uppsrc/Core/Heap.h
index 11085270d..ad995b179 100644
--- a/uppsrc/Core/Heap.h
+++ b/uppsrc/Core/Heap.h
@@ -11,6 +11,7 @@ void *MemoryAlloc48();
 void  MemoryFree48(void *ptr);
 void  MemoryFreeThread();
 void  MemoryCheck();
+void  MemoryDump();
 int   MemoryUsedKb();
 int   MemoryUsedKbMax();
 void  MemoryLimitKb(int kb);
diff --git a/uppsrc/Core/HeapImp.h b/uppsrc/Core/HeapImp.h
index 3c43e81d6..8dbda627a 100644
--- a/uppsrc/Core/HeapImp.h
+++ b/uppsrc/Core/HeapImp.h
@@ -254,10 +254,18 @@ typename BlkHeap<Detail, BlkSize>::BlkHeader *BlkHeap<Detail, BlkSize>::Free(Blk
 }
 
 struct HugeHeapDetail {
+#if 0
 	static BlkHeader_<4096> freelist[2][1];
 
 	static void LinkFree(BlkHeader_<4096> *h)     { Dbl_LinkAfter(h, freelist[h->GetSize() >= 16]); }
 	static void NewFreeSize(BlkHeader_<4096> *h)  {}
+#else
+	static BlkHeader_<4096> freelist[20][1];
+
+	static int  Cv(int n)                         { return n < 16 ? 0 : SignificantBits(n - 16) + 1; }
+	static void LinkFree(BlkHeader_<4096> *h)     { Dbl_LinkAfter(h, freelist[Cv(h->GetSize())]); }
+	static void NewFreeSize(BlkHeader_<4096> *h)  {}
+#endif
 };
 
 struct Heap : BlkHeap<HugeHeapDetail, 4096> {
@@ -269,6 +277,7 @@ struct Heap : BlkHeap<HugeHeapDetail, 4096> {
 	#endif
 		LUNIT = 256, // granularity of large blocks (size always a multiple of this)
 		LPAGE = LUNIT - 1, // number of LUNITs in large page
+		LCVCOUNT = 9, // SignificantBits(LPAGE) + 1
 		LOFFSET = 64, // offset from 64KB start to the first block header
 
 		NKLASS = 23, // number of small size classes
@@ -315,8 +324,11 @@ struct Heap : BlkHeap<HugeHeapDetail, 4096> {
 	};
 	
 	struct LargeHeapDetail {
-		BlkHeader_<LUNIT> freelist[6][1]; // <1KB, <2KB, <4KB, <8KB, >= 8KB
-		static int Cv(int n) { return min(n >> 2, 4); }
+//		BlkHeader_<LUNIT> freelist[6][1]; // <1KB, <2KB, <4KB, <8KB, >= 8KB
+//		static int Cv(int n) { return min(n >> 2, 4); }
+
+		BlkHeader_<LUNIT> freelist[LCVCOUNT][1];
+		static int Cv(int n) { return SignificantBits(n); }
 
 		void Free64KB(BlkHeader_<LUNIT> *h);
 		void LinkFree(BlkHeader_<LUNIT> *h) {
@@ -431,6 +443,7 @@ struct Heap : BlkHeap<HugeHeapDetail, 4096> {
 	size_t LGetBlockSize(void *ptr);
 
 	void   Make(MemoryProfile& f);
+	void   Dump();
 
 	static void Shrink();
 
diff --git a/uppsrc/Core/Ops.h b/uppsrc/Core/Ops.h
index d56453c7b..5e913ec7f 100644
--- a/uppsrc/Core/Ops.h
+++ b/uppsrc/Core/Ops.h
@@ -288,3 +288,14 @@ inline dword FoldHash(dword h)
 {
 	return SwapEndian32(0xa3613c16 * h);
 }
+
+force_inline
+int SignificantBits(dword x)
+{ // basically log2(x) + 1 except that for 0 this is 0, number of significant bits of x
+#ifdef COMPILER_MSC
+	DWORD index;
+	return _BitScanReverse(&index, x) ? index + 1 : 0;
+#else
+	return x ? 32 - __builtin_clz(x) : 0;
+#endif
+}
diff --git a/uppsrc/Core/heaputil.cpp b/uppsrc/Core/heaputil.cpp
index a2e3cd806..1702e9822 100644
--- a/uppsrc/Core/heaputil.cpp
+++ b/uppsrc/Core/heaputil.cpp
@@ -181,6 +181,35 @@ void Heap::Make(MemoryProfile& f)
 	}
 }
 
+void Heap::Dump()
+{
+	Mutex::Lock __(mutex);
+	DLink *m = large->next;
+	while(m != large) {
+		LargeHeap::BlkHeader *h = m->GetFirst();
+		RLOG("--------------------------");
+		for(;;) {
+			RLOG(asString(h) << " " << h->GetSize() << (h->IsFree() ? " FREE" : ""));
+			if(h->IsLast())
+				break;
+			h = h->GetNextHeader();
+		}
+		m = m->next;
+	}
+	HugePage *pg = huge_pages;
+	while(pg) {
+		BlkPrefix *h = (BlkPrefix *)pg->page;
+		RLOG("==========================");
+		for(;;) {
+			RLOG(asString(h) << " " << h->GetSize() << (h->IsFree() ? " FREE" : ""));
+			if(h->IsLast())
+				break;
+			h = h->GetNextHeader(4096);
+		}
+		pg = pg->next;
+	}
+}
+
 String AsString(const MemoryProfile& mem)
 {
 	String text;
@@ -189,7 +218,7 @@ String AsString(const MemoryProfile& mem)
 	size_t asize = 0;
 	int fcount = 0;
 	size_t fsize = 0;
-	text << "Memory peak " << MemoryUsedKbMax() << "\n";
+	text << "Memory peak: " << MemoryUsedKbMax() << " KB, current: " << MemoryUsedKb() << "KB \n";
 	for(int i = 0; i < 1024; i++)
 		if(mem.allocated[i]) {
 			int sz = 4 * i;
@@ -210,14 +239,8 @@ String AsString(const MemoryProfile& mem)
 	     << ", total size " << (mem.large_fragments_total >> 10) << " KB\n";
 	text << "Huge block count " << mem.huge_count
 	     << ", total size " << int(mem.huge_total >> 10) << " KB\n";
-	size_t hf = 0;
-	int    cnt = 0;
-	for(int i = 0; i < 65535; i++) {
-		hf += 4 * mem.huge_fragments[i];
-		cnt += !!mem.huge_fragments[i];
-	}
-	text << "Huge fragments count " << cnt
-	     << ", total size " << hf << " KB\n";
+	text << "Huge fragments count " << mem.huge_fragments_count
+	     << ", total size " << 4 * mem.huge_fragments_total << " KB\n";
 	text << "Sys block count " << mem.sys_count
 	     << ", total size " << int(mem.sys_total >> 10) << " KB\n";
 	text << Heap::HPAGE * 4 / 1024 << "MB master blocks " << mem.master_chunks << "\n";
diff --git a/uppsrc/Core/hheap.cpp b/uppsrc/Core/hheap.cpp
index 5d57a810c..0f6430cf5 100644
--- a/uppsrc/Core/hheap.cpp
+++ b/uppsrc/Core/hheap.cpp
@@ -14,7 +14,7 @@ namespace Upp {
 // used as manager of huge memory blocks. 4KB and 64KB blocks are allocated from here too
 // also able to deal with bigger blocks, those are directly allocated / freed from system
 
-BlkHeader_<4096> HugeHeapDetail::freelist[2][1]; // only single global Huge heap...
+BlkHeader_<4096> HugeHeapDetail::freelist[20][1]; // only single global Huge heap...
 Heap::HugePage *Heap::huge_pages;
 
 #ifdef LSTAT
@@ -58,17 +58,19 @@ void *Heap::HugeAlloc(size_t count) // count in 4kb pages
 #endif
 
 	huge_4KB_count += count;
-	
-	if(huge_4KB_count > huge_4KB_count_max) {
-		huge_4KB_count_max = huge_4KB_count;
-		if(MemoryUsedKb() > sKBLimit)
-			Panic("MemoryLimitKb breached!");
-		if(sPeak)
-			Make(*sPeak);
-	}
+
+	auto MaxMem = [&] {
+		if(huge_4KB_count > huge_4KB_count_max) {
+			huge_4KB_count_max = huge_4KB_count;
+			if(MemoryUsedKb() > sKBLimit)
+				Panic("MemoryLimitKb breached!");
+			if(sPeak)
+				Make(*sPeak);
+		}
+	};
 
 	if(!D::freelist[0]->next) { // initialization
-		for(int i = 0; i < 2; i++)
+		for(int i = 0; i < __countof(D::freelist); i++)
 			Dbl_Self(D::freelist[i]);
 	}
 		
@@ -80,6 +82,7 @@ void *Heap::HugeAlloc(size_t count) // count in 4kb pages
 		*((size_t *)sysblk) = count;
 		sys_count++;
 		sys_size += 4096 * count;
+		MaxMem();
 		return h;
 	}
 	
@@ -91,13 +94,16 @@ void *Heap::HugeAlloc(size_t count) // count in 4kb pages
 		FreeSmallEmpty(INT_MAX, int(free_4KB - huge_4KB_count / 32));
 	
 	for(int pass = 0; pass < 2; pass++) {
-		for(int i = count >= 16; i < 2; i++) {
+		for(int i = Cv(count); i < __countof(D::freelist); i++) {
 			BlkHeader *l = D::freelist[i];
 			BlkHeader *h = l->next;
 			while(h != l) {
 				word sz = h->GetSize();
-				if(sz >= count)
-					return MakeAlloc(h, wcount);
+				if(sz >= count) {
+					void *ptr = MakeAlloc(h, wcount);
+					MaxMem();
+					return ptr;
+				}
 				h = h->next;
 			}
 		}
diff --git a/uppsrc/Core/lheap.cpp b/uppsrc/Core/lheap.cpp
index d4d04eebf..61857c0a5 100644
--- a/uppsrc/Core/lheap.cpp
+++ b/uppsrc/Core/lheap.cpp
@@ -135,7 +135,7 @@ void Heap::LFree(void *ptr)
 	if(h->heap == NULL) { // this is big block
 		LTIMING("Big Free");
 		DLink *d = (DLink *)h - 1;
-		big_size -= h->size;
+		big_size -= d->size;
 		big_count--;
 		d->Unlink();
 		LLOG("Big free " << (void *) ptr << " size " << h->size);
@@ -182,9 +182,9 @@ bool   Heap::TryRealloc(void *ptr, size_t& newsize)
 		size_t count = (newsize + sizeof(DLink) + sizeof(BlkPrefix) + 4095) >> 12;
 		
 		if(HugeTryRealloc(d, count)) {
-			big_size -= h->size;
+			big_size -= d->size;
 			d->size = newsize = (count << 12) - sizeof(DLink) - sizeof(BlkPrefix);
-			big_size += h->size;
+			big_size += d->size;
 			return true;
 		}
 	}
diff --git a/uppsrc/Core/sheap.cpp b/uppsrc/Core/sheap.cpp
index d7457b601..72edbe7c2 100644
--- a/uppsrc/Core/sheap.cpp
+++ b/uppsrc/Core/sheap.cpp
@@ -465,6 +465,11 @@ MemoryProfile::MemoryProfile()
 	ThreadHeap()->Make(*this);
 }
 
+void MemoryDump()
+{
+	ThreadHeap()->Dump();
+}
+
 #endif
 
 }
diff --git a/uppsrc/ide/ide.upp b/uppsrc/ide/ide.upp
index 7d0c6e850..0979ad5da 100644
--- a/uppsrc/ide/ide.upp
+++ b/uppsrc/ide/ide.upp
@@ -124,7 +124,8 @@ mainconfig
 	"" = "GUI MT X11",
 	"" = "GUI MT NOGTK",
 	"" = "GUI NOGTK",
-	"" = "GUI MT TEST_HIDPI";
+	"" = "GUI MT TEST_HIDPI",
+	"" = "GUI PEAKMEM";
 
 custom() "",
 	"ASDFASDFASDF",
diff --git a/uppsrc/ide/main.cpp b/uppsrc/ide/main.cpp
index abaadb24d..fb046b085 100644
--- a/uppsrc/ide/main.cpp
+++ b/uppsrc/ide/main.cpp
@@ -124,6 +124,10 @@ void AppMain___()
 {
 //	Ctrl::ShowRepaint(50);
 
+#ifdef flagPEAKMEM
+	PeakMemoryProfile();
+#endif
+
 	Logi() << UPP_FUNCTION_NAME << "(): " << SplashCtrl::GenerateVersionInfo(' ');
 
 	Ctrl::SetUHDEnabled();
@@ -331,3 +335,11 @@ void AppMain___()
 #endif
 #endif
 }
+
+#ifdef flagPEAKMEM
+EXITBLOCK {
+	RDUMP(*PeakMemoryProfile());
+	RDUMP(MemoryProfile());
+	MemoryDump();
+}
+#endif