Merge branch 'sverker/one_offheap_list/OTP-8737' into dev

* sverker/one_offheap_list/OTP-8737:
  One off-heap list, to eliminate two words per ETS object.

28 files changed, 447 insertions, 803 deletions

diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index 596ad9a010..4fc271d41c 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -402,7 +402,7 @@ check_process_code(Process* rp, Module* modp)
     BeamInstr* end;
     Eterm* sp;
 #ifndef HYBRID /* FIND ME! */
-    ErlFunThing* funp;
+    struct erl_off_heap_header* oh;
     int done_gc = 0;
 #endif
 
@@ -470,27 +470,30 @@ check_process_code(Process* rp, Module* modp)
 
 #ifndef HYBRID /* FIND ME! */
  rescan:
-    for (funp = MSO(rp).funs; funp; funp = funp->next) {
-	BeamInstr* fun_code;
-
-	fun_code = funp->fe->address;
-
-	if (INSIDE((BeamInstr *) funp->fe->address)) {
-	    if (done_gc) {
-		return am_true;
-	    } else {
-		/*
-		 * Try to get rid of this fun by garbage collecting.
-		 * Clear both fvalue and ftrace to make sure they
-		 * don't hold any funs.
-		 */
-		rp->freason = EXC_NULL;
-		rp->fvalue = NIL;
-		rp->ftrace = NIL;
-		done_gc = 1;
-                FLAGS(rp) |= F_NEED_FULLSWEEP;
-		(void) erts_garbage_collect(rp, 0, rp->arg_reg, rp->arity);
-		goto rescan;
+    for (oh = MSO(rp).first; oh; oh = oh->next) {
+	if (thing_subtag(oh->thing_word) == FUN_SUBTAG) {
+	    ErlFunThing* funp = (ErlFunThing*) oh;
+	    BeamInstr* fun_code;
+
+	    fun_code = funp->fe->address;
+
+	    if (INSIDE((BeamInstr *) funp->fe->address)) {
+		if (done_gc) {
+		    return am_true;
+		} else {
+		    /*
+		    * Try to get rid of this fun by garbage collecting.
+		    * Clear both fvalue and ftrace to make sure they
+		    * don't hold any funs.
+		    */
+		    rp->freason = EXC_NULL;
+		    rp->fvalue = NIL;
+		    rp->ftrace = NIL;
+		    done_gc = 1;
+		    FLAGS(rp) |= F_NEED_FULLSWEEP;
+		    (void) erts_garbage_collect(rp, 0, rp->arg_reg, rp->arity);
+		    goto rescan;
+		}
 	    }
 	}
     }
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index c0680086aa..2c37b26a39 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -3385,8 +3385,8 @@ apply_bif_or_nif_epilogue:
 	 HTOP += PROC_BIN_SIZE;
 	 pb->thing_word = HEADER_PROC_BIN;
 	 pb->size = num_bytes;
-	 pb->next = MSO(c_p).mso;
-	 MSO(c_p).mso = pb;
+	 pb->next = MSO(c_p).first;
+	 MSO(c_p).first = (struct erl_off_heap_header*) pb;
 	 pb->val = bptr;
 	 pb->bytes = (byte*) bptr->orig_bytes;
 	 pb->flags = 0;
@@ -3486,8 +3486,8 @@ apply_bif_or_nif_epilogue:
 	 HTOP += PROC_BIN_SIZE;
 	 pb->thing_word = HEADER_PROC_BIN;
 	 pb->size = tmp_arg1;
-	 pb->next = MSO(c_p).mso;
-	 MSO(c_p).mso = pb;
+	 pb->next = MSO(c_p).first;
+	 MSO(c_p).first = (struct erl_off_heap_header*) pb;
 	 pb->val = bptr;
 	 pb->bytes = (byte*) bptr->orig_bytes;
 	 pb->flags = 0;
@@ -6323,8 +6323,8 @@ new_fun(Process* p, Eterm* reg, ErlFunEntry* fe, int num_free)
     erts_refc_inc(&fe->refc, 2);
     funp->thing_word = HEADER_FUN;
 #ifndef HYBRID /* FIND ME! */
-    funp->next = MSO(p).funs;
-    MSO(p).funs = funp;
+    funp->next = MSO(p).first;
+    MSO(p).first = (struct erl_off_heap_header*) funp;
 #endif
     funp->fe = fe;
     funp->num_free = num_free;
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 506bf383ca..6e9755ad48 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -3611,11 +3611,11 @@ BIF_RETTYPE list_to_pid_1(BIF_ALIST_1)
 
       etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
       etp->header = make_external_pid_header(1);
-      etp->next = MSO(BIF_P).externals;
+      etp->next = MSO(BIF_P).first;
       etp->node = enp;
       etp->data.ui[0] = make_pid_data(c, b);
 
-      MSO(BIF_P).externals = etp;
+      MSO(BIF_P).first = (struct erl_off_heap_header*) etp;
       erts_deref_dist_entry(dep);
       BIF_RET(make_external_pid(etp));
     }
diff --git a/erts/emulator/beam/binary.c b/erts/emulator/beam/binary.c
index c68392fad4..3fd714f9c2 100644
--- a/erts/emulator/beam/binary.c
+++ b/erts/emulator/beam/binary.c
@@ -88,8 +88,8 @@ new_binary(Process *p, byte *buf, int len)
     pb = (ProcBin *) HAlloc(p, PROC_BIN_SIZE);
     pb->thing_word = HEADER_PROC_BIN;
     pb->size = len;
-    pb->next = MSO(p).mso;
-    MSO(p).mso = pb;
+    pb->next = MSO(p).first;
+    MSO(p).first = (struct erl_off_heap_header*)pb;
     pb->val = bptr;
     pb->bytes = (byte*) bptr->orig_bytes;
     pb->flags = 0;
@@ -127,8 +127,8 @@ Eterm erts_new_mso_binary(Process *p, byte *buf, int len)
     pb = (ProcBin *) HAlloc(p, PROC_BIN_SIZE);
     pb->thing_word = HEADER_PROC_BIN;
     pb->size = len;
-    pb->next = MSO(p).mso;
-    MSO(p).mso = pb;
+    pb->next = MSO(p).first;
+    MSO(p).first = (struct erl_off_heap_header*)pb;
     pb->val = bptr;
     pb->bytes = (byte*) bptr->orig_bytes;
     pb->flags = 0;
@@ -487,16 +487,6 @@ BIF_RETTYPE split_binary_2(BIF_ALIST_2)
 	BIF_ERROR(BIF_P, BADARG);
 }
 
-void
-erts_cleanup_mso(ProcBin* pb)
-{
-    while (pb != NULL) {
-	ProcBin* next = pb->next;
-	if (erts_refc_dectest(&pb->val->refc, 0) == 0)
-	    erts_bin_free(pb->val);
-	pb = next;
-    }
-}
 
 /*
  * Local functions.
diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c
index 857cb177c8..f339e19761 100644
--- a/erts/emulator/beam/break.c
+++ b/erts/emulator/beam/break.c
@@ -611,29 +611,29 @@ static void
 bin_check(void)
 {
     Process  *rp;
-    ProcBin *bp;
-    int i, printed;
+    struct erl_off_heap_header* hdr;
+    int i, printed = 0;
 
     for (i=0; i < erts_max_processes; i++) {
 	if ((rp = process_tab[i]) == NULL)
 	    continue;
-	if (!(bp = rp->off_heap.mso))
-	    continue;
-	printed = 0;
-	while (bp) {
-	    if (printed == 0) {
-		erts_printf("Process %T holding binary data \n", rp->id);
-		printed = 1;
+	for (hdr = rp->off_heap.first; hdr; hdr = hdr->next) {
+	    if (hdr->thing_word == HEADER_PROC_BIN) {
+		ProcBin *bp = (ProcBin*) hdr;
+		if (!printed) {
+		    erts_printf("Process %T holding binary data \n", rp->id);
+		    printed = 1;
+		}
+		erts_printf("0x%08lx orig_size: %ld, norefs = %ld\n",
+			    (unsigned long)bp->val, 
+			    (long)bp->val->orig_size, 
+			    erts_smp_atomic_read(&bp->val->refc));
 	    }
-	    erts_printf("0x%08lx orig_size: %ld, norefs = %ld\n",
-		       (unsigned long)bp->val, 
-		       (long)bp->val->orig_size, 
-		       erts_smp_atomic_read(&bp->val->refc));
-
-	    bp = bp->next;
 	}
-	if (printed == 1)
+	if (printed) {
 	    erts_printf("--------------------------------------\n");
+	    printed = 0;
+	}
     }
     /* db_bin_check() has to be rewritten for the AVL trees... */
     /*db_bin_check();*/ 
diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c
index 521a1b1788..57be0169ba 100644
--- a/erts/emulator/beam/copy.c
+++ b/erts/emulator/beam/copy.c
@@ -314,9 +314,9 @@ copy_struct(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
 		    *argp = make_binary(hbot);
 		    pb = (ProcBin*) hbot;
 		    erts_refc_inc(&pb->val->refc, 2);
-		    pb->next = off_heap->mso;
+		    pb->next = off_heap->first;
 		    pb->flags = 0;
-		    off_heap->mso = pb;
+		    off_heap->first = (struct erl_off_heap_header*) pb;
 		    off_heap->overhead += pb->size / sizeof(Eterm);
 		}
 		break;
@@ -363,9 +363,9 @@ copy_struct(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
 			to->val = from->val;
 			erts_refc_inc(&to->val->refc, 2);
 			to->bytes = from->bytes + offset;
-			to->next = off_heap->mso;
+			to->next = off_heap->first;
 			to->flags = 0;
-			off_heap->mso = to;
+			off_heap->first = (struct erl_off_heap_header*) to;
 			off_heap->overhead += to->size / sizeof(Eterm);
 		    }
 		    *argp = make_binary(hbot);
@@ -396,8 +396,8 @@ copy_struct(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
 		    }
 #ifndef HYBRID /* FIND ME! */
 		    funp = (ErlFunThing *) tp;
-		    funp->next = off_heap->funs;
-		    off_heap->funs = funp;
+		    funp->next = off_heap->first;
+		    off_heap->first = (struct erl_off_heap_header*) funp;
 		    erts_refc_inc(&funp->fe->refc, 2);
 #endif
 		    *argp = make_fun(tp);
@@ -416,8 +416,8 @@ copy_struct(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
 		    *htop++ = *objp++;
 		  }
 
-		  etp->next = off_heap->externals;
-		  off_heap->externals = etp;
+		  etp->next = off_heap->first;
+		  off_heap->first = (struct erl_off_heap_header*)etp;
 		  erts_refc_inc(&etp->node->refc, 2);
 
 		  *argp = make_external(tp);
@@ -650,8 +650,8 @@ Eterm copy_struct_lazy(Process *from, Eterm orig, Uint offs)
                     *hp++ = *objp++;
                 }
                 erts_refc_inc(&pb->val->refc, 2);
-                pb->next = erts_global_offheap.mso;
-                erts_global_offheap.mso = pb;
+                pb->next = erts_global_offheap.first;
+                erts_global_offheap.first = pb;
                 erts_global_offheap.overhead += pb->size / sizeof(Eterm);
                 continue;
             }
@@ -672,9 +672,9 @@ Eterm copy_struct_lazy(Process *from, Eterm orig, Uint offs)
                 while (i--) {
                     *hp++ = *objp++;
                 }
-#ifndef HYBRID // FIND ME!
-                funp->next = erts_global_offheap.funs;
-                erts_global_offheap.funs = funp;
+#ifndef HYBRID /* FIND ME! */
+                funp->next = erts_global_offheap.first;
+                erts_global_offheap.first = funp;
                 erts_refc_inc(&funp->fe->refc, 2);
 #endif
                 for (i = k; i < j; i++) {
@@ -718,8 +718,8 @@ Eterm copy_struct_lazy(Process *from, Eterm orig, Uint offs)
                     *hp++ = *objp++;
                 }
 
-                etp->next = erts_global_offheap.externals;
-                erts_global_offheap.externals = etp;
+                etp->next = erts_global_offheap.first;
+                erts_global_offheap.first = etp;
 		erts_refc_inc(&etp->node->refc, 2);
                 continue;
             }
@@ -775,8 +775,8 @@ Eterm copy_struct_lazy(Process *from, Eterm orig, Uint offs)
                     to_bin->size = real_size;
                     to_bin->val = from_bin->val;
                     to_bin->bytes = from_bin->bytes + sub_offset;
-                    to_bin->next = erts_global_offheap.mso;
-                    erts_global_offheap.mso = to_bin;
+                    to_bin->next = erts_global_offheap.first;
+                    erts_global_offheap.first = to_bin;
                     erts_global_offheap.overhead += to_bin->size / sizeof(Eterm);
 		    res_binary=make_binary(to_bin);
 		    hp += PROC_BIN_SIZE;
@@ -910,57 +910,43 @@ copy_shallow(Eterm* ptr, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
 		break;
 	    case REFC_BINARY_SUBTAG:
 		{
-		    ProcBin* pb = (ProcBin *) (hp-1);
-		    int tari = thing_arityval(val);
-
-		    sz -= tari;
-		    while (tari--) {
-			*hp++ = *tp++;
-		    }
+		    ProcBin* pb = (ProcBin *) (tp-1);
 		    erts_refc_inc(&pb->val->refc, 2);
-		    pb->next = off_heap->mso;
-		    off_heap->mso = pb;
 		    off_heap->overhead += pb->size / sizeof(Eterm);
 		}
-		break;
+		goto off_heap_common;
+
 	    case FUN_SUBTAG:
 		{
-#ifndef HYBRID /* FIND ME! */
-		    ErlFunThing* funp = (ErlFunThing *) (hp-1);
-#endif
-		    int tari = thing_arityval(val);
-
-		    sz -= tari;
-		    while (tari--) {
-			*hp++ = *tp++;
-		    }
-#ifndef HYBRID /* FIND ME! */
-		    funp->next = off_heap->funs;
-		    off_heap->funs = funp;
+		    ErlFunThing* funp = (ErlFunThing *) (tp-1);
 		    erts_refc_inc(&funp->fe->refc, 2);
-#endif
 		}
-		break;
+		goto off_heap_common;
+
 	    case EXTERNAL_PID_SUBTAG:
 	    case EXTERNAL_PORT_SUBTAG:
 	    case EXTERNAL_REF_SUBTAG:
 		{
-		    ExternalThing* etp = (ExternalThing *) (hp-1);
+		    ExternalThing* etp = (ExternalThing *) (tp-1);
+		    erts_refc_inc(&etp->node->refc, 2);
+		}
+	    off_heap_common:
+		{
+		    struct erl_off_heap_header* ohh = (struct erl_off_heap_header*)(hp-1);
 		    int tari = thing_arityval(val);
-
+		    
 		    sz -= tari;
 		    while (tari--) {
 			*hp++ = *tp++;
 		    }
-		    etp->next = off_heap->externals;
-		    off_heap->externals = etp;
-		    erts_refc_inc(&etp->node->refc, 2);
+		    ohh->next = off_heap->first;
+		    off_heap->first = ohh;
 		}
 		break;
 	    default:
 		{
 		    int tari = header_arity(val);
-
+    
 		    sz -= tari;
 		    while (tari--) {
 			*hp++ = *tp++;
@@ -1029,12 +1015,6 @@ void move_multi_frags(Eterm** hpp, ErlOffHeap* off_heap, ErlHeapFragment* first,
 static void
 move_one_frag(Eterm** hpp, Eterm* src, Uint src_sz, ErlOffHeap* off_heap)
 {
-    union {
-	Uint *up;
-	ProcBin *pbp;
-	ErlFunThing *efp;
-	ExternalThing *etp;
-    } ohe;
     Eterm* ptr = src;
     Eterm* end = ptr + src_sz;
     Eterm dummy_ref;
@@ -1046,23 +1026,17 @@ move_one_frag(Eterm** hpp, Eterm* src, Uint src_sz, ErlOffHeap* off_heap)
 	val = *ptr;
 	ASSERT(val != ERTS_HOLE_MARKER);
 	if (is_header(val)) {
+	    struct erl_off_heap_header* hdr = (struct erl_off_heap_header*)hp;
 	    ASSERT(ptr + header_arity(val) < end);
-	    ohe.up = hp;
 	    MOVE_BOXED(ptr, val, hp, &dummy_ref);	    
 	    switch (val & _HEADER_SUBTAG_MASK) {
 	    case REFC_BINARY_SUBTAG:
-		ohe.pbp->next = off_heap->mso;
-		off_heap->mso = ohe.pbp;
-		break;
 	    case FUN_SUBTAG:
-		ohe.efp->next = off_heap->funs;
-		off_heap->funs = ohe.efp;
-		break;
 	    case EXTERNAL_PID_SUBTAG:
 	    case EXTERNAL_PORT_SUBTAG:
 	    case EXTERNAL_REF_SUBTAG:
-		ohe.etp->next = off_heap->externals;
-		off_heap->externals = ohe.etp;
+		hdr->next = off_heap->first;
+		off_heap->first = hdr;
 		break;
 	    }
 	}
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index d465017949..16b6aeac3f 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -922,12 +922,8 @@ int erts_net_message(Port *prt,
 
     UseTmpHeapNoproc(DIST_CTL_DEFAULT_SIZE);
     /* Thanks to Luke Gorrie */
-    off_heap.mso = NULL;
-#ifndef HYBRID /* FIND ME! */
-    off_heap.funs = NULL;
-#endif
+    off_heap.first = NULL;
     off_heap.overhead = 0;
-    off_heap.externals = NULL;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
@@ -1434,16 +1430,8 @@ int erts_net_message(Port *prt,
 	}
     }
 
-    if (off_heap.mso) {
-	erts_cleanup_mso(off_heap.mso);
-    }
-    if (off_heap.externals) {
-	erts_cleanup_externals(off_heap.externals);
-    }
+    erts_cleanup_offheap(&off_heap);
 #ifndef HYBRID /* FIND ME! */
-    if (off_heap.funs) {
-	erts_cleanup_funs(off_heap.funs);
-    }
     if (ctl != ctl_default) {
 	erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
     }
@@ -1453,16 +1441,8 @@ int erts_net_message(Port *prt,
     return 0;
 
  data_error:
-    if (off_heap.mso) {
-	erts_cleanup_mso(off_heap.mso);
-    }
-    if (off_heap.externals) {
-	erts_cleanup_externals(off_heap.externals);
-    }
+    erts_cleanup_offheap(&off_heap);
 #ifndef HYBRID /* FIND ME! */
-    if (off_heap.funs) {
-	erts_cleanup_funs(off_heap.funs);
-    }
     if (ctl != ctl_default) {
 	erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
     }
diff --git a/erts/emulator/beam/erl_bif_binary.c b/erts/emulator/beam/erl_bif_binary.c
index 82f1e06e8e..1d8fd11b7b 100644
--- a/erts/emulator/beam/erl_bif_binary.c
+++ b/erts/emulator/beam/erl_bif_binary.c
@@ -2511,8 +2511,8 @@ BIF_RETTYPE binary_copy_trap(BIF_ALIST_2)
 	pb = (ProcBin *) HAlloc(BIF_P, PROC_BIN_SIZE);
 	pb->thing_word = HEADER_PROC_BIN;
 	pb->size = target_size;
-	pb->next = MSO(BIF_P).mso;
-	MSO(BIF_P).mso = pb;
+	pb->next = MSO(BIF_P).first;
+	MSO(BIF_P).first = (struct erl_off_heap_header*) pb;
 	pb->val = save;
 	pb->bytes = t;
 	pb->flags = 0;
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 48cda52612..ca1ab44012 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -122,22 +122,26 @@ static char erts_system_version[] = ("Erlang " ERLANG_OTP_RELEASE
 #endif
 
 static Eterm
-bld_bin_list(Uint **hpp, Uint *szp, ProcBin* pb)
+bld_bin_list(Uint **hpp, Uint *szp, ErlOffHeap* oh)
 {
+    struct erl_off_heap_header* ohh;
     Eterm res = NIL;
     Eterm tuple;
 
-    for (; pb; pb = pb->next) {
-	Eterm val = erts_bld_uword(hpp, szp, (UWord) pb->val);
-	Eterm orig_size = erts_bld_uint(hpp, szp, pb->val->orig_size);
-
-	if (szp)
-	    *szp += 4+2;
-	if (hpp) {
-	    Uint refc = (Uint) erts_smp_atomic_read(&pb->val->refc);
-	    tuple = TUPLE3(*hpp, val, orig_size, make_small(refc));
-	    res = CONS(*hpp + 4, tuple, res);
-	    *hpp += 4+2;
+    for (ohh = oh->first; ohh; ohh = ohh->next) {
+	if (ohh->thing_word == HEADER_PROC_BIN) {
+	    ProcBin* pb = (ProcBin*) ohh;
+	    Eterm val = erts_bld_uword(hpp, szp, (UWord) pb->val);
+	    Eterm orig_size = erts_bld_uint(hpp, szp, pb->val->orig_size);
+    
+	    if (szp)
+		*szp += 4+2;
+	    if (hpp) {
+		Uint refc = (Uint) erts_smp_atomic_read(&pb->val->refc);
+		tuple = TUPLE3(*hpp, val, orig_size, make_small(refc));
+		res = CONS(*hpp + 4, tuple, res);
+		*hpp += 4+2;
+	    }
 	}
     }
     return res;
@@ -176,10 +180,10 @@ static void do_make_one_mon_element(ErtsMonitor *mon, void * vpmlc)
     Eterm tup;
     Eterm r = (IS_CONST(mon->ref)
 	       ? mon->ref
-	       : STORE_NC(&(pmlc->hp), &MSO(pmlc->p).externals, mon->ref));
+	       : STORE_NC(&(pmlc->hp), &MSO(pmlc->p), mon->ref));
     Eterm p = (IS_CONST(mon->pid)
 	       ? mon->pid
-	       : STORE_NC(&(pmlc->hp), &MSO(pmlc->p).externals, mon->pid));
+	       : STORE_NC(&(pmlc->hp), &MSO(pmlc->p), mon->pid));
     tup = TUPLE5(pmlc->hp, pmlc->tag, make_small(mon->type), r, p, mon->name);
     pmlc->hp += 6;
     pmlc->res = CONS(pmlc->hp, tup, pmlc->res);
@@ -240,7 +244,7 @@ static void do_make_one_lnk_element(ErtsLink *lnk, void * vpllc)
     Eterm old_res, targets = NIL;
     Eterm p = (IS_CONST(lnk->pid)
 	       ? lnk->pid
-	       : STORE_NC(&(pllc->hp), &MSO(pllc->p).externals, lnk->pid));
+	       : STORE_NC(&(pllc->hp), &MSO(pllc->p), lnk->pid));
     if (lnk->type == LINK_NODE) {
 	targets = make_small(ERTS_LINK_REFC(lnk));
     } else if (ERTS_LINK_ROOT(lnk) != NULL) {
@@ -1225,7 +1229,7 @@ process_info_aux(Process *BIF_P,
 	hp = HAlloc(BIF_P, 3 + mic.sz);
 	res = NIL;
 	for (i = 0; i < mic.mi_i; i++) {
-	    item = STORE_NC(&hp, &MSO(BIF_P).externals, mic.mi[i].entity); 
+	    item = STORE_NC(&hp, &MSO(BIF_P), mic.mi[i].entity); 
 	    res = CONS(hp, item, res);
 	    hp += 2;
 	}
@@ -1258,9 +1262,7 @@ process_info_aux(Process *BIF_P,
 	    else {
 		/* Monitor by pid. Build {process, Pid} and cons it. */
 		Eterm t;
-		Eterm pid = STORE_NC(&hp,
-				     &MSO(BIF_P).externals,
-				     mic.mi[i].entity);
+		Eterm pid = STORE_NC(&hp, &MSO(BIF_P), mic.mi[i].entity);
 		t = TUPLE2(hp, am_process, pid);
 		hp += 3;
 		res = CONS(hp, t, res);
@@ -1282,7 +1284,7 @@ process_info_aux(Process *BIF_P,
 
 	res = NIL;
 	for (i = 0; i < mic.mi_i; ++i) {
-	    item = STORE_NC(&hp, &MSO(BIF_P).externals, mic.mi[i].entity); 
+	    item = STORE_NC(&hp, &MSO(BIF_P), mic.mi[i].entity); 
 	    res = CONS(hp, item, res);
 	    hp += 2;
 	}
@@ -1491,7 +1493,7 @@ process_info_aux(Process *BIF_P,
     case am_group_leader: {
 	int sz = NC_HEAP_SIZE(rp->group_leader);
 	hp = HAlloc(BIF_P, 3 + sz);
-	res = STORE_NC(&hp, &MSO(BIF_P).externals, rp->group_leader);
+	res = STORE_NC(&hp, &MSO(BIF_P), rp->group_leader);
 	break;
     }
 
@@ -1516,9 +1518,9 @@ process_info_aux(Process *BIF_P,
 
     case am_binary: {
 	Uint sz = 3;
-	(void) bld_bin_list(NULL, &sz, MSO(rp).mso);
+	(void) bld_bin_list(NULL, &sz, &MSO(rp));
 	hp = HAlloc(BIF_P, sz);
-	res = bld_bin_list(&hp, NULL, MSO(rp).mso);
+	res = bld_bin_list(&hp, NULL, &MSO(rp));
 	break;
     }
 
@@ -2678,7 +2680,7 @@ BIF_RETTYPE port_info_2(BIF_ALIST_2)
 	hp = HAlloc(BIF_P, 3 + mic.sz);
 	res = NIL;
 	for (i = 0; i < mic.mi_i; i++) {
-	    item = STORE_NC(&hp, &MSO(BIF_P).externals, mic.mi[i].entity); 
+	    item = STORE_NC(&hp, &MSO(BIF_P), mic.mi[i].entity); 
 	    res = CONS(hp, item, res);
 	    hp += 2;
 	}
@@ -2698,7 +2700,7 @@ BIF_RETTYPE port_info_2(BIF_ALIST_2)
 	res = NIL;
 	for (i = 0; i < mic.mi_i; i++) {
 	    Eterm t;
-	    item = STORE_NC(&hp, &MSO(BIF_P).externals, mic.mi[i].entity); 
+	    item = STORE_NC(&hp, &MSO(BIF_P), mic.mi[i].entity); 
 	    t = TUPLE2(hp, am_process, item);
 	    hp += 3;
 	    res = CONS(hp, t, res);
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 443cac9033..0509e51a6f 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -2161,7 +2161,7 @@ trace_delivered_1(BIF_ALIST_1)
 #ifdef ERTS_SMP
     bp = new_message_buffer(REF_THING_SIZE + 4);
     hp = &bp->mem[0];
-    msg_ref = STORE_NC(&hp, &bp->off_heap.externals, ref);
+    msg_ref = STORE_NC(&hp, &bp->off_heap, ref);
 #else
     hp = HAlloc(BIF_P, 4);
     msg_ref = ref;
diff --git a/erts/emulator/beam/erl_bits.c b/erts/emulator/beam/erl_bits.c
index defe18c92b..96faa673f6 100644
--- a/erts/emulator/beam/erl_bits.c
+++ b/erts/emulator/beam/erl_bits.c
@@ -1335,8 +1335,8 @@ erts_bs_append(Process* c_p, Eterm* reg, Uint live, Eterm build_size_term,
 	hp += PROC_BIN_SIZE;
 	pb->thing_word = HEADER_PROC_BIN;
 	pb->size = used_size_in_bytes;
-	pb->next = MSO(c_p).mso;
-	MSO(c_p).mso = pb;
+	pb->next = MSO(c_p).first;
+	MSO(c_p).first = (struct erl_off_heap_header*)pb;
 	pb->val = bptr;
 	pb->bytes = (byte*) bptr->orig_bytes;
 	pb->flags = PB_IS_WRITABLE | PB_ACTIVE_WRITER;
@@ -1506,8 +1506,8 @@ erts_bs_init_writable(Process* p, Eterm sz)
     hp += PROC_BIN_SIZE;
     pb->thing_word = HEADER_PROC_BIN;
     pb->size = 0;
-    pb->next = MSO(p).mso;
-    MSO(p).mso = pb;
+    pb->next = MSO(p).first;
+    MSO(p).first = (struct erl_off_heap_header*) pb;
     pb->val = bptr;
     pb->bytes = (byte*) bptr->orig_bytes;
     pb->flags = PB_IS_WRITABLE | PB_ACTIVE_WRITER;
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 124129a371..96008ccef0 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -2751,11 +2751,7 @@ static void db_finalize_dbterm_hash(DbUpdateHandle* handle)
 	newDbTerm = &newp->dbterm;
     
 	newDbTerm->size = handle->new_size;
-	newDbTerm->off_heap.mso = NULL;
-	newDbTerm->off_heap.externals = NULL;
-    #ifndef HYBRID /* FIND ME! */
-	newDbTerm->off_heap.funs = NULL;
-    #endif
+	newDbTerm->off_heap.first = NULL;
 	newDbTerm->off_heap.overhead = 0;
 	
 	/* make a flat copy */
diff --git a/erts/emulator/beam/erl_db_tree.c b/erts/emulator/beam/erl_db_tree.c
index 96e577ed90..da2696163a 100644
--- a/erts/emulator/beam/erl_db_tree.c
+++ b/erts/emulator/beam/erl_db_tree.c
@@ -2589,11 +2589,7 @@ static void db_finalize_dbterm_tree(DbUpdateHandle* handle)
 	newDbTerm = &newp->dbterm;
     
 	newDbTerm->size = handle->new_size;
-	newDbTerm->off_heap.mso = NULL;
-	newDbTerm->off_heap.externals = NULL;
-    #ifndef HYBRID /* FIND ME! */
-	newDbTerm->off_heap.funs = NULL;
-    #endif
+	newDbTerm->off_heap.first = NULL;
 	newDbTerm->off_heap.overhead = 0;
 	
 	/* make a flat copy */
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index 93a47eb76f..48e0080525 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -363,12 +363,7 @@ static ErtsMatchPseudoProcess *match_pseudo_process;
 static ERTS_INLINE void
 cleanup_match_pseudo_process(ErtsMatchPseudoProcess *mpsp, int keep_heap)
 {
-    if (mpsp->process.mbuf
-	|| mpsp->process.off_heap.mso
-#ifndef HYBRID /* FIND ME! */
-	|| mpsp->process.off_heap.funs
-#endif
-	|| mpsp->process.off_heap.externals) {
+    if (mpsp->process.mbuf || mpsp->process.off_heap.first) {
 	erts_cleanup_empty_process(&mpsp->process);
     }
 #ifdef DEBUG
@@ -2495,11 +2490,7 @@ void* db_get_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
 	p = (DbTerm*) ((void *)(((char *) structp) + offset));
     }
     p->size = size;
-    p->off_heap.mso = NULL;
-    p->off_heap.externals = NULL;
-#ifndef HYBRID /* FIND ME! */
-    p->off_heap.funs = NULL;
-#endif
+    p->off_heap.first = NULL;
     p->off_heap.overhead = 0;
 
     top = DBTERM_BUF(p);
diff --git a/erts/emulator/beam/erl_fun.c b/erts/emulator/beam/erl_fun.c
index 15d9538301..1f74393a96 100644
--- a/erts/emulator/beam/erl_fun.c
+++ b/erts/emulator/beam/erl_fun.c
@@ -192,20 +192,6 @@ erts_erase_fun_entry(ErlFunEntry* fe)
     erts_fun_write_unlock();
 }
 
-#ifndef HYBRID /* FIND ME! */
-void
-erts_cleanup_funs(ErlFunThing* funp)
-{
-    while (funp) {
-	ErlFunEntry* fe = funp->fe;
-	if (erts_refc_dectest(&fe->refc, 0) == 0) {
-	    erts_erase_fun_entry(fe);
-	}
-	funp = funp->next;
-    }
-}
-#endif
-
 void
 erts_cleanup_funs_on_purge(BeamInstr* start, BeamInstr* end)
 {
diff --git a/erts/emulator/beam/erl_fun.h b/erts/emulator/beam/erl_fun.h
index 944d4b3df5..2f165afa06 100644
--- a/erts/emulator/beam/erl_fun.h
+++ b/erts/emulator/beam/erl_fun.h
@@ -53,10 +53,10 @@ typedef struct erl_fun_entry {
 
 typedef struct erl_fun_thing {
     Eterm thing_word;		/* Subtag FUN_SUBTAG. */
+    ErlFunEntry* fe;		/* Pointer to fun entry. */
 #ifndef HYBRID /* FIND ME! */
-    struct erl_fun_thing* next;	/* Next fun in mso list. */
+    struct erl_off_heap_header* next;
 #endif
-    ErlFunEntry* fe;		/* Pointer to fun entry. */
 #ifdef HIPE
     UWord* native_address;	/* Native code for the fun. */
 #endif
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index a19e090f1e..e9411389a0 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -110,9 +110,7 @@ static Uint adjust_after_fullsweep(Process *p, int size_before,
 				   int need, Eterm *objv, int nobj);
 static void shrink_new_heap(Process *p, Uint new_sz, Eterm *objv, int nobj);
 static void grow_new_heap(Process *p, Uint new_sz, Eterm* objv, int nobj);
-static void sweep_proc_bins(Process *p, int fullsweep);
-static void sweep_proc_funs(Process *p, int fullsweep);
-static void sweep_proc_externals(Process *p, int fullsweep);
+static void sweep_off_heap(Process *p, int fullsweep);
 static void offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size);
 static void offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size);
 static void offset_rootset(Process *p, Sint offs, char* area, Uint area_size,
@@ -145,6 +143,13 @@ erts_init_gc(void)
 {
     int i = 0;
 
+    ASSERT(offsetof(ProcBin,thing_word) == offsetof(struct erl_off_heap_header,thing_word));
+    ASSERT(offsetof(ProcBin,thing_word) == offsetof(ErlFunThing,thing_word));
+    ASSERT(offsetof(ProcBin,thing_word) == offsetof(ExternalThing,header));
+    ASSERT(offsetof(ProcBin,next) == offsetof(struct erl_off_heap_header,next));
+    ASSERT(offsetof(ProcBin,next) == offsetof(ErlFunThing,next));
+    ASSERT(offsetof(ProcBin,next) == offsetof(ExternalThing,next));
+
     erts_smp_spinlock_init(&info_lck, "gc_info");
     garbage_cols = 0;
     reclaimed = 0;
@@ -286,25 +291,14 @@ erts_offset_heap_ptr(Eterm* hp, Uint sz, Sint offs,
     offset_heap_ptr(hp, sz, offs, (char *) low, ((char *)high)-((char *)low));
 }
 
+
 #define ptr_within(ptr, low, high) ((ptr) < (high) && (ptr) >= (low))
 
 void
 erts_offset_off_heap(ErlOffHeap *ohp, Sint offs, Eterm* low, Eterm* high)
 {
-    if (ohp->mso && ptr_within((Eterm *)ohp->mso, low, high)) {
-        Eterm** uptr = (Eterm**) (void *) &ohp->mso;
-        *uptr += offs;
-    }
-
-#ifndef HYBRID /* FIND ME! */
-    if (ohp->funs && ptr_within((Eterm *)ohp->funs, low, high)) {
-        Eterm** uptr = (Eterm**) (void *) &ohp->funs;
-        *uptr += offs;
-    }
-#endif
-
-    if (ohp->externals && ptr_within((Eterm *)ohp->externals, low, high)) {
-        Eterm** uptr = (Eterm**) (void *) &ohp->externals;
+    if (ohp->first && ptr_within((Eterm *)ohp->first, low, high)) {
+        Eterm** uptr = (Eterm**) (void *) &ohp->first;
         *uptr += offs;
     }
 }
@@ -504,14 +498,8 @@ erts_garbage_collect_hibernate(Process* p)
 
     cleanup_rootset(&rootset);
 
-    if (MSO(p).mso) {
-        sweep_proc_bins(p, 1);
-    }
-    if (MSO(p).funs) {
-        sweep_proc_funs(p, 1);
-    }
-    if (MSO(p).externals) {
-        sweep_proc_externals(p, 1);
+    if (MSO(p).first) {
+        sweep_off_heap(p, 1);
     }
 
     /*
@@ -1041,15 +1029,8 @@ do_minor(Process *p, int new_sz, Eterm* objv, int nobj)
     OLD_HTOP(p) = old_htop;
     HIGH_WATER(p) = (HEAP_START(p) != HIGH_WATER(p)) ? n_heap : n_htop;
 
-    if (MSO(p).mso) {
-        sweep_proc_bins(p, 0);
-    }
-
-    if (MSO(p).funs) {
-        sweep_proc_funs(p, 0);
-    }
-    if (MSO(p).externals) {
-        sweep_proc_externals(p, 0);
+    if (MSO(p).first) {
+	sweep_off_heap(p, 0);
     }
 
 #ifdef HARDDEBUG
@@ -1271,17 +1252,11 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
 	}
     }
 
-    if (MSO(p).mso) {
-	sweep_proc_bins(p, 1);
-    }
-    if (MSO(p).funs) {
-	sweep_proc_funs(p, 1);
-    }
-    if (MSO(p).externals) {
-	sweep_proc_externals(p, 1);
+    if (MSO(p).first) {
+	sweep_off_heap(p, 1);
     }
 
-    if (OLD_HEAP(p) != NULL) {
+    if (OLD_HEAP(p) != NULL) {       
 	ERTS_HEAP_FREE(ERTS_ALC_T_OLD_HEAP,
 		       OLD_HEAP(p),
 		       (OLD_HEND(p) - OLD_HEAP(p)) * sizeof(Eterm));
@@ -1305,6 +1280,7 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
     HIGH_WATER(p) = HEAP_TOP(p);
 
     ErtsGcQuickSanityCheck(p);
+
     /*
      * Copy newly received message onto the end of the new heap.
      */
@@ -2044,108 +2020,24 @@ next_vheap_size(Process* p, Uint vheap, Uint vheap_sz) {
     return vheap_sz < p->min_vheap_size ? p->min_vheap_size : vheap_sz;
 }
 
-static void
-sweep_proc_externals(Process *p, int fullsweep)
-{
-    ExternalThing** prev;
-    ExternalThing* ptr;
-    char* oh = 0;
-    Uint oh_size = 0;
-
-    if (fullsweep == 0) {
-	oh = (char *) OLD_HEAP(p);
-	oh_size = (char *) OLD_HEND(p) - oh;
-    }
-
-    prev = &MSO(p).externals;
-    ptr = MSO(p).externals;
-
-    while (ptr) {
-        Eterm* ppt = (Eterm *) ptr;
-
-        if (IS_MOVED_BOXED(*ppt)) {        /* Object is alive */
-            ExternalThing* ro = external_thing_ptr(*ppt);
-
-            *prev = ro;         /* Patch to moved pos */
-            prev = &ro->next;
-            ptr = ro->next;
-        } else if (in_area(ppt, oh, oh_size)) {
-            /*
-             * Object resides on old heap, and we just did a
-             * generational collection - keep object in list.
-             */
-            prev = &ptr->next;
-            ptr = ptr->next;
-        } else {                /* Object has not been moved - deref it */
-	    erts_deref_node_entry(ptr->node);
-            *prev = ptr = ptr->next;
-        }
-    }
-    ASSERT(*prev == NULL);
-}
-
-static void
-sweep_proc_funs(Process *p, int fullsweep)
-{
-    ErlFunThing** prev;
-    ErlFunThing* ptr;
-    char* oh = 0;
-    Uint oh_size = 0;
-
-    if (fullsweep == 0) {
-	oh = (char *) OLD_HEAP(p);
-	oh_size = (char *) OLD_HEND(p) - oh;
-    }
-		      
-    prev = &MSO(p).funs;
-    ptr = MSO(p).funs;
-
-    while (ptr) {
-        Eterm* ppt = (Eterm *) ptr;
-
-        if (IS_MOVED_BOXED(*ppt)) {        /* Object is alive */
-            ErlFunThing* ro = (ErlFunThing *) fun_val(*ppt);
-
-            *prev = ro;         /* Patch to moved pos */
-            prev = &ro->next;
-            ptr = ro->next;
-        } else if (in_area(ppt, oh, oh_size)) {
-            /*
-             * Object resides on old heap, and we just did a
-             * generational collection - keep object in list.
-             */
-            prev = &ptr->next;
-            ptr = ptr->next;
-        } else {                /* Object has not been moved - deref it */
-            ErlFunEntry* fe = ptr->fe;
-
-            *prev = ptr = ptr->next;
-	    if (erts_refc_dectest(&fe->refc, 0) == 0) {
-                erts_erase_fun_entry(fe);
-            }
-        }
-    }
-    ASSERT(*prev == NULL);
-}
-
 struct shrink_cand_data {
-    ProcBin* new_candidates;
-    ProcBin* new_candidates_end;
-    ProcBin* old_candidates;
+    struct erl_off_heap_header* new_candidates;
+    struct erl_off_heap_header* new_candidates_end;
+    struct erl_off_heap_header* old_candidates;
     Uint no_of_candidates;
     Uint no_of_active;
 };
 
 static ERTS_INLINE void
 link_live_proc_bin(struct shrink_cand_data *shrink,
-		   ProcBin ***prevppp,
-		   ProcBin **pbpp,
+		   struct erl_off_heap_header*** prevppp,
+		   struct erl_off_heap_header** currpp,
 		   int new_heap)
 {
-    ProcBin *pbp = *pbpp;
-
-    *pbpp = pbp->next;
+    ProcBin *pbp = (ProcBin*) *currpp;
+    ASSERT(**prevppp == *currpp);
 
+    *currpp = pbp->next;
     if (pbp->flags & (PB_ACTIVE_WRITER|PB_IS_WRITABLE)) {
 	ASSERT(((pbp->flags & (PB_ACTIVE_WRITER|PB_IS_WRITABLE))
 		== (PB_ACTIVE_WRITER|PB_IS_WRITABLE))
@@ -2162,15 +2054,16 @@ link_live_proc_bin(struct shrink_cand_data *shrink,
 	    /* Our allocators are 8 byte aligned, i.e., shrinking with
 	       less than 8 bytes will have no real effect */
 	    if (unused >= 8) { /* A shrink candidate; save in candidate list */
+		**prevppp = pbp->next;
 		if (new_heap) {
 		    if (!shrink->new_candidates)
-			shrink->new_candidates_end = pbp;
+			shrink->new_candidates_end = (struct erl_off_heap_header*)pbp;
 		    pbp->next = shrink->new_candidates;
-		    shrink->new_candidates = pbp;
+		    shrink->new_candidates = (struct erl_off_heap_header*)pbp;
 		}
 		else {
 		    pbp->next = shrink->old_candidates;
-		    shrink->old_candidates = pbp;
+		    shrink->old_candidates = (struct erl_off_heap_header*)pbp;
 		}
 		shrink->no_of_candidates++;
 		return;
@@ -2178,67 +2071,101 @@ link_live_proc_bin(struct shrink_cand_data *shrink,
 	}
     }
 
-    /* Not a shrink candidate; keep in original mso list */
-    **prevppp = pbp;
+    /* Not a shrink candidate; keep in original mso list */ 
     *prevppp = &pbp->next;
-
 }
 
 
 static void 
-sweep_proc_bins(Process *p, int fullsweep)
+sweep_off_heap(Process *p, int fullsweep)
 {
     struct shrink_cand_data shrink = {0};
-    ProcBin** prev;
-    ProcBin* ptr;
-    Binary* bptr;
-    char* oh = NULL;
-    Uint oh_size = 0;
+    struct erl_off_heap_header* ptr;
+    struct erl_off_heap_header** prev;
+    char* oheap = NULL;
+    Uint oheap_sz = 0;
     Uint bin_vheap = 0;
+#ifdef DEBUG
+    int seen_mature = 0;
+#endif
 
     if (fullsweep == 0) {
-	oh = (char *) OLD_HEAP(p);
-	oh_size = (char *) OLD_HEND(p) - oh;
+	oheap = (char *) OLD_HEAP(p);
+	oheap_sz = (char *) OLD_HEND(p) - oheap;
     }
 
     BIN_OLD_VHEAP(p) = 0;
 
-    prev = &MSO(p).mso;
-    ptr = MSO(p).mso;
+    prev = &MSO(p).first;
+    ptr = MSO(p).first;
 
-    /*
-     * Note: In R7 we no longer force a fullsweep when we find binaries
-     * on the old heap. The reason is that with the introduction of the
-     * bit syntax we can expect binaries to be used a lot more. Note that
-     * in earlier releases a brand new binary (or any other term) could
-     * be put on the old heap during a gen-gc fullsweep, but this is
-     * no longer the case in R7.
+    /* Firts part of the list will reside on the (old) new-heap.
+     * Keep if moved, otherwise deref.
      */
     while (ptr) {
-        Eterm* ppt = (Eterm *) ptr;
-
-        if (IS_MOVED_BOXED(*ppt)) {        /* Object is alive */
-	    bin_vheap += ptr->size / sizeof(Eterm);
-            ptr = (ProcBin*) binary_val(*ppt);		   
-	    link_live_proc_bin(&shrink,
-			       &prev,
-			       &ptr,
-			       !in_area(ptr, oh, oh_size)); 
-        } else if (in_area(ppt, oh, oh_size)) {
-            /*
-             * Object resides on old heap, and we just did a
-             * generational collection - keep object in list.
-             */
-            BIN_OLD_VHEAP(p) += ptr->size / sizeof(Eterm); /* for binary gc (words)*/
-	    link_live_proc_bin(&shrink, &prev, &ptr, 0); 
-        } else {                /* Object has not been moved - deref it */
-
-            *prev = ptr->next;
-            bptr = ptr->val;
-            if (erts_refc_dectest(&bptr->refc, 0) == 0)
-		erts_bin_free(bptr);
-            ptr = *prev;
-        }
+	if (IS_MOVED_BOXED(ptr->thing_word)) {
+	    ASSERT(!in_area(ptr, oheap, oheap_sz));
+	    *prev = ptr = (struct erl_off_heap_header*) boxed_val(ptr->thing_word);
+	    ASSERT(!IS_MOVED_BOXED(ptr->thing_word));
+	    if (ptr->thing_word == HEADER_PROC_BIN) {
+		int to_new_heap = !in_area(ptr, oheap, oheap_sz);
+		ASSERT(to_new_heap == !seen_mature || (!to_new_heap && (seen_mature=1)));
+		if (to_new_heap) {
+		    bin_vheap += ptr->u.size / sizeof(Eterm);
+		} else {
+		    BIN_OLD_VHEAP(p) += ptr->u.size / sizeof(Eterm); /* for binary gc (words)*/
+		}		
+		link_live_proc_bin(&shrink, &prev, &ptr, to_new_heap);
+	    }
+	    else {
+		prev = &ptr->next;
+		ptr = ptr->next;
+	    }
+	}
+	else if (!in_area(ptr, oheap, oheap_sz)) {
+	    /* garbage */
+	    switch (thing_subtag(ptr->thing_word)) {
+	    case REFC_BINARY_SUBTAG:
+		{
+		    Binary* bptr = ((ProcBin*)ptr)->val;	
+		    if (erts_refc_dectest(&bptr->refc, 0) == 0) {
+			erts_bin_free(bptr);
+		    }
+		    break;
+		}
+	    case FUN_SUBTAG:
+		{
+		    ErlFunEntry* fe = ((ErlFunThing*)ptr)->fe;
+		    if (erts_refc_dectest(&fe->refc, 0) == 0) {
+			erts_erase_fun_entry(fe);
+		    }
+		    break;
+		}
+	    default:
+		ASSERT(is_external_header(ptr->thing_word));
+		erts_deref_node_entry(((ExternalThing*)ptr)->node);
+	    }
+	    *prev = ptr = ptr->next;
+	}
+	else break; /* and let old-heap loop continue */
+    }
+
+    /* The rest of the list resides on old-heap, and we just did a
+     * generational collection - keep objects in list.
+     */
+    while (ptr) {
+	ASSERT(in_area(ptr, oheap, oheap_sz));
+	ASSERT(!IS_MOVED_BOXED(ptr->thing_word));       
+	if (ptr->thing_word == HEADER_PROC_BIN) {
+	    BIN_OLD_VHEAP(p) += ptr->u.size / sizeof(Eterm); /* for binary gc (words)*/
+	    link_live_proc_bin(&shrink, &prev, &ptr, 0);
+	}
+	else {
+	    ASSERT(is_fun_header(ptr->thing_word) ||
+		   is_external_header(ptr->thing_word));
+	    prev = &ptr->next;
+	    ptr = ptr->next;
+	}
     }
 
     if (BIN_OLD_VHEAP(p) >= BIN_OLD_VHEAP_SZ(p)) {
@@ -2254,7 +2181,8 @@ sweep_proc_bins(Process *p, int fullsweep)
      */
 
     if (shrink.no_of_candidates) {
-	ProcBin *candlist[] = {shrink.new_candidates, shrink.old_candidates};
+	ProcBin *candlist[] = { (ProcBin*)shrink.new_candidates,
+	                        (ProcBin*)shrink.old_candidates };
 	Uint leave_unused = 0;
 	int i;
 
@@ -2266,21 +2194,21 @@ sweep_proc_bins(Process *p, int fullsweep)
 	}
 
 	for (i = 0; i < sizeof(candlist)/sizeof(candlist[0]); i++) {
-
-	    for (ptr = candlist[i]; ptr; ptr = ptr->next) {
-		Uint new_size = ptr->size;
+	    ProcBin* pb;
+	    for (pb = candlist[i]; pb; pb = (ProcBin*)pb->next) {
+		Uint new_size = pb->size;
 
 		if (leave_unused) {
 		    new_size += (new_size * 100) / leave_unused;
 		    /* Our allocators are 8 byte aligned, i.e., shrinking with
 		       less than 8 bytes will have no real effect */
-		    if (new_size + 8 >= ptr->val->orig_size)
+		    if (new_size + 8 >= pb->val->orig_size)
 			continue;
 		}
 
-		ptr->val = erts_bin_realloc(ptr->val, new_size);
-		ptr->val->orig_size = new_size;
-		ptr->bytes = (byte *) ptr->val->orig_bytes;
+		pb->val = erts_bin_realloc(pb->val, new_size);
+		pb->val->orig_size = new_size;
+		pb->bytes = (byte *) pb->val->orig_bytes;
 	    }
 	}
 
@@ -2289,21 +2217,20 @@ sweep_proc_bins(Process *p, int fullsweep)
 	 * We now potentially have the mso list divided into three lists:
 	 * - shrink candidates on new heap (inactive writable with unused data)
 	 * - shrink candidates on old heap (inactive writable with unused data)
-	 * - other binaries (read only + active writable ...)
+	 * - other binaries (read only + active writable ...) + funs and externals
 	 *
 	 * Put them back together: new candidates -> other -> old candidates
 	 * This order will ensure that the list only refers from new
 	 * generation to old and never from old to new *which is important*.
 	 */
 	if (shrink.new_candidates) {
-	    if (prev == &MSO(p).mso) /* empty other binaries list */
+	    if (prev == &MSO(p).first) /* empty other binaries list */
 		prev = &shrink.new_candidates_end->next;
 	    else
-		shrink.new_candidates_end->next = MSO(p).mso;
-	    MSO(p).mso = shrink.new_candidates;
+		shrink.new_candidates_end->next = MSO(p).first;
+	    MSO(p).first = shrink.new_candidates;
 	}
     }
-
     *prev = shrink.old_candidates;
 }
 
@@ -2334,15 +2261,17 @@ offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size)
 	      tari = thing_arityval(val);
 	      switch (thing_subtag(val)) {
 	      case REFC_BINARY_SUBTAG:
+	      case FUN_SUBTAG:
+	      case EXTERNAL_PID_SUBTAG:
+	      case EXTERNAL_PORT_SUBTAG:
+	      case EXTERNAL_REF_SUBTAG:
 		  {
-		      ProcBin* pb = (ProcBin*) hp;
-		      Eterm** uptr = (Eterm **) (void *) &pb->next;
+		      struct erl_off_heap_header* oh = (struct erl_off_heap_header*) hp;
 
-		      if (*uptr && in_area((Eterm *)pb->next, area, area_size)) {
+		      if (in_area(oh->next, area, area_size)) {
+			  Eterm** uptr = (Eterm **) (void *) &oh->next;
 			  *uptr += offs; /* Patch the mso chain */
 		      }
-		      sz -= tari;
-		      hp += tari + 1;
 		  }
 		  break;
 	      case BIN_MATCHSTATE_SUBTAG:
@@ -2353,40 +2282,11 @@ offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size)
 		      mb->orig = offset_ptr(mb->orig, offs);
 		      mb->base = binary_bytes(mb->orig);
 		  }
-		  sz -= tari;
-		  hp += tari + 1;
 		}
 		break;
-	      case FUN_SUBTAG:
-		  {
-		      ErlFunThing* funp = (ErlFunThing *) hp;
-		      Eterm** uptr = (Eterm **) (void *) &funp->next;
-
-		      if (*uptr && in_area((Eterm *)funp->next, area, area_size)) {
-			  *uptr += offs;
-		      }
-		      sz -= tari;
-		      hp += tari + 1;
-		  }
-		  break;
-	      case EXTERNAL_PID_SUBTAG:
-	      case EXTERNAL_PORT_SUBTAG:
-	      case EXTERNAL_REF_SUBTAG:
-		  {
-		      ExternalThing* etp = (ExternalThing *) hp;
-		      Eterm** uptr = (Eterm **) (void *) &etp->next;
-
-		      if (*uptr && in_area((Eterm *)etp->next, area, area_size)) {
-			  *uptr += offs;
-		      }
-		      sz -= tari;
-		      hp += tari + 1;
-		  }
-		  break;
-	      default:
-		  sz -= tari;
-		  hp += tari + 1;
 	      }
+	      sz -= tari;
+	      hp += tari + 1;
 	      break;
 	  }
 	  default:
@@ -2423,18 +2323,8 @@ offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size)
 static void
 offset_off_heap(Process* p, Sint offs, char* area, Uint area_size)
 {
-    if (MSO(p).mso && in_area((Eterm *)MSO(p).mso, area, area_size)) {
-        Eterm** uptr = (Eterm**) (void *) &MSO(p).mso;
-        *uptr += offs;
-    }
-
-    if (MSO(p).funs && in_area((Eterm *)MSO(p).funs, area, area_size)) {
-        Eterm** uptr = (Eterm**) (void *) &MSO(p).funs;
-        *uptr += offs;
-    }
-
-    if (MSO(p).externals && in_area((Eterm *)MSO(p).externals, area, area_size)) {
-        Eterm** uptr = (Eterm**) (void *) &MSO(p).externals;
+    if (MSO(p).first && in_area((Eterm *)MSO(p).first, area, area_size)) {
+        Eterm** uptr = (Eterm**) (void *) &MSO(p).first;
         *uptr += offs;
     }
 }
@@ -2555,8 +2445,8 @@ do {							\
 		 __FILE__, __LINE__, #EXP);		\
 } while (0)
 
-#ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_EXTERNAL_LIST
-#  define ERTS_EXTERNAL_VISITED_BIT ((Eterm) 1 << 31)
+#ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_LIST
+#  define ERTS_OFFHEAP_VISITED_BIT ((Eterm) 1 << 31)
 #endif
 
 
@@ -2566,62 +2456,45 @@ erts_check_off_heap2(Process *p, Eterm *htop)
     Eterm *oheap = (Eterm *) OLD_HEAP(p);
     Eterm *ohtop = (Eterm *) OLD_HTOP(p);
     int old;
-    ProcBin *pb;
-    ErlFunThing *eft;
-    ExternalThing *et;
+    union erl_off_heap_ptr u;
 
     old = 0;
-    for (pb = MSO(p).mso; pb; pb = pb->next) {
-	Eterm *ptr = (Eterm *) pb;
-	long refc = erts_refc_read(&pb->val->refc, 1);
+    for (u.hdr = MSO(p).first; u.hdr; u.hdr = u.hdr->next) {
+	long refc;
+	switch (thing_subtag(u.hdr->thing_word)) {
+	case REFC_BINARY_SUBTAG:
+	    refc = erts_refc_read(&u.pb->val->refc, 1);		
+	    break;
+	case FUN_SUBTAG:
+	    refc = erts_refc_read(&u.fun->fe->refc, 1);
+	    break;
+	case EXTERNAL_PID_SUBTAG:
+	case EXTERNAL_PORT_SUBTAG:
+	case EXTERNAL_REF_SUBTAG:
+	    refc = erts_refc_read(&u.ext->node->refc, 1);
+	    break;
+	default:
+	    ASSERT(!!"erts_check_off_heap2: Invalid thing_word");
+	}
 	ERTS_CHK_OFFHEAP_ASSERT(refc >= 1);
+#ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_LIST
+	ERTS_CHK_OFFHEAP_ASSERT(!(u.hdr->thing_word & ERTS_EXTERNAL_VISITED_BIT));
+	u.hdr->thing_word |= ERTS_OFFHEAP_VISITED_BIT;
+#endif
 	if (old) {
-	    ERTS_CHK_OFFHEAP_ASSERT(oheap <= ptr && ptr < ohtop);
+	    ERTS_CHK_OFFHEAP_ASSERT(oheap <= u.ep && u.ep < ohtop);
 	}
-	else if (oheap <= ptr && ptr < ohtop)
+	else if (oheap <= u.ep && u.ep < ohtop)
 	    old = 1;
 	else {
-	    ERTS_CHK_OFFHEAP_ASSERT(within2(ptr, p, htop));
+	    ERTS_CHK_OFFHEAP_ASSERT(within2(u.ep, p, htop));
 	}
     }
 
-    old = 0;
-    for (eft = MSO(p).funs; eft; eft = eft->next) {
-	Eterm *ptr = (Eterm *) eft;
-	long refc = erts_refc_read(&eft->fe->refc, 1);
-	ERTS_CHK_OFFHEAP_ASSERT(refc >= 1);
-	if (old)
-	    ERTS_CHK_OFFHEAP_ASSERT(oheap <= ptr && ptr < ohtop);
-	else if (oheap <= ptr && ptr < ohtop)
-	    old = 1;
-	else
-	    ERTS_CHK_OFFHEAP_ASSERT(within2(ptr, p, htop));
-    }
-
-    old = 0;
-    for (et = MSO(p).externals; et; et = et->next) {
-	Eterm *ptr = (Eterm *) et;
-	long refc = erts_refc_read(&et->node->refc, 1);
-	ERTS_CHK_OFFHEAP_ASSERT(refc >= 1);
-#ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_EXTERNAL_LIST
-	ERTS_CHK_OFFHEAP_ASSERT(!(et->header & ERTS_EXTERNAL_VISITED_BIT));
-#endif
-	if (old)
-	    ERTS_CHK_OFFHEAP_ASSERT(oheap <= ptr && ptr < ohtop);
-	else if (oheap <= ptr && ptr < ohtop)
-	    old = 1;
-	else
-	    ERTS_CHK_OFFHEAP_ASSERT(within2(ptr, p, htop));
-#ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_EXTERNAL_LIST
-	et->header |= ERTS_EXTERNAL_VISITED_BIT;
-#endif
-    }
-
 #ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_EXTERNAL_LIST
-    for (et = MSO(p).externals; et; et = et->next)
-	et->header &= ~ERTS_EXTERNAL_VISITED_BIT;
+    for (u.hdr = MSO(p).first; u.hdr; u.hdr = u.hdr->next)
+	u.hdr->thing_word &= ~ERTS_OFFHEAP_VISITED_BIT;
 #endif
-	
 }
 
 void
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index b63f3df7df..1f61dca230 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -30,6 +30,7 @@
 #include "erl_message.h"
 #include "erl_process.h"
 #include "erl_nmgc.h"
+#include "erl_binary.h"
 
 ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(message,
 				 ErlMessage,
@@ -164,16 +165,25 @@ erts_resize_message_buffer(ErlHeapFragment *bp, Uint size,
 void
 erts_cleanup_offheap(ErlOffHeap *offheap)
 {
-    if (offheap->mso) {
-	erts_cleanup_mso(offheap->mso);
-    }
-#ifndef HYBRID /* FIND ME! */
-    if (offheap->funs) {
-	erts_cleanup_funs(offheap->funs);
-    }
-#endif
-    if (offheap->externals) {
-	erts_cleanup_externals(offheap->externals);
+    union erl_off_heap_ptr u;
+
+    for (u.hdr = offheap->first; u.hdr; u.hdr = u.hdr->next) {
+	switch (thing_subtag(u.hdr->thing_word)) {
+	case REFC_BINARY_SUBTAG:
+	    if (erts_refc_dectest(&u.pb->val->refc, 0) == 0) {
+		erts_bin_free(u.pb->val);
+	    }
+	    break;
+	case FUN_SUBTAG:
+	    if (erts_refc_dectest(&u.fun->fe->refc, 0) == 0) {
+		erts_erase_fun_entry(u.fun->fe);		    
+	    }
+	    break;
+	default:
+	    ASSERT(is_external_header(u.hdr->thing_word));
+	    erts_deref_node_entry(u.ext->node);
+	    break;
+	}
     }
 }
 
@@ -201,41 +211,17 @@ link_mbuf_to_proc(Process *proc, ErlHeapFragment *bp)
 	MBUF_SIZE(proc) += bp->used_size;
 	FLAGS(proc) |= F_FORCE_GC;
 
-	/* Move any binaries into the process */
-	if (bp->off_heap.mso != NULL) {
-	    ProcBin** next_p = &bp->off_heap.mso;
+	/* Move any off_heap's into the process */
+	if (bp->off_heap.first != NULL) {
+	    struct erl_off_heap_header** next_p = &bp->off_heap.first;
 	    while (*next_p != NULL) {
 		next_p = &((*next_p)->next);
 	    }
-	    *next_p = MSO(proc).mso;
-	    MSO(proc).mso = bp->off_heap.mso;
-	    bp->off_heap.mso = NULL;
+	    *next_p = MSO(proc).first;
+	    MSO(proc).first = bp->off_heap.first;
+	    bp->off_heap.first = NULL;
 	    MSO(proc).overhead += bp->off_heap.overhead;
 	}
-
-	/* Move any funs into the process */
-#ifndef HYBRID
-	if (bp->off_heap.funs != NULL) {
-	    ErlFunThing** next_p = &bp->off_heap.funs;
-	    while (*next_p != NULL) {
-		next_p = &((*next_p)->next);
-	    }
-	    *next_p = MSO(proc).funs;
-	    MSO(proc).funs = bp->off_heap.funs;
-	    bp->off_heap.funs = NULL;
-	}
-#endif
-
-	/* Move any external things into the process */
-	if (bp->off_heap.externals != NULL) {
-	    ExternalThing** next_p = &bp->off_heap.externals;
-	    while (*next_p != NULL) {
-		next_p = &((*next_p)->next);
-	    }
-	    *next_p = MSO(proc).externals;
-	    MSO(proc).externals = bp->off_heap.externals;
-	    bp->off_heap.externals = NULL;
-	}
     }
 }
 
@@ -506,19 +492,7 @@ erts_link_mbuf_to_proc(struct process *proc, ErlHeapFragment *bp)
 void
 erts_move_msg_mbuf_to_heap(Eterm** hpp, ErlOffHeap* off_heap, ErlMessage *msg)
 {
-    /* Unions for typecasts avoids warnings about type-punned pointers and aliasing */
-    union {
-	Uint** upp;
-	ProcBin **pbpp;
-	ErlFunThing **efpp;
-	ExternalThing **etpp;
-    } oh_list_pp, oh_el_next_pp;
-    union {
-	Uint *up;
-	ProcBin *pbp;
-	ErlFunThing *efp;
-	ExternalThing *etp;
-    } oh_el_p;
+    struct erl_off_heap_header* oh;
     Eterm term, token, *fhp, *hp;
     Sint offs;
     Uint sz;
@@ -571,9 +545,7 @@ erts_move_msg_mbuf_to_heap(Eterm** hpp, ErlOffHeap* off_heap, ErlMessage *msg)
     hp = *hpp;
     offs = hp - fhp;
 
-    oh_list_pp.upp = NULL;
-    oh_el_next_pp.upp = NULL; /* Shut up compiler warning */
-    oh_el_p.up = NULL; /* Shut up compiler warning */
+    oh = NULL;
     while (sz--) {
 	Uint cpy_sz;
 	Eterm val = *fhp++;
@@ -593,25 +565,11 @@ erts_move_msg_mbuf_to_heap(Eterm** hpp, ErlOffHeap* off_heap, ErlMessage *msg)
 	    case ARITYVAL_SUBTAG:
 		break;
 	    case REFC_BINARY_SUBTAG:
-		oh_list_pp.pbpp = &off_heap->mso;
-		oh_el_p.up = (hp-1);
-		oh_el_next_pp.pbpp = &(oh_el_p.pbp)->next;
-		cpy_sz = thing_arityval(val);
-		goto cpy_words;
 	    case FUN_SUBTAG:
-#ifndef HYBRID
-		oh_list_pp.efpp = &off_heap->funs;
-		oh_el_p.up = (hp-1);
-		oh_el_next_pp.efpp = &(oh_el_p.efp)->next;
-#endif
-		cpy_sz = thing_arityval(val);
-		goto cpy_words;
 	    case EXTERNAL_PID_SUBTAG:
 	    case EXTERNAL_PORT_SUBTAG:
 	    case EXTERNAL_REF_SUBTAG:
-		oh_list_pp.etpp = &off_heap->externals;
-		oh_el_p.up = (hp-1);
-		oh_el_next_pp.etpp =  &(oh_el_p.etp)->next;
+		oh = (struct erl_off_heap_header*) (hp-1);
 		cpy_sz = thing_arityval(val);
 		goto cpy_words;
 	    default:
@@ -641,44 +599,13 @@ erts_move_msg_mbuf_to_heap(Eterm** hpp, ErlOffHeap* off_heap, ErlMessage *msg)
 		case 1: *hp++ = *fhp++;
 		default: break;
 		}
-		if (oh_list_pp.upp) {
-#ifdef HARD_DEBUG
-		    Uint *dbg_old_oh_list_p = *oh_list_pp.upp;
-#endif
+		if (oh) {
 		    /* Add to offheap list */
-		    *oh_el_next_pp.upp = *oh_list_pp.upp;
-		    *oh_list_pp.upp = oh_el_p.up;
-		    ASSERT(*hpp <= oh_el_p.up);
-		    ASSERT(hp > oh_el_p.up);
-#ifdef HARD_DEBUG
-		    switch (val & _HEADER_SUBTAG_MASK) {
-		    case REFC_BINARY_SUBTAG:
-			ASSERT(off_heap->mso == *oh_list_pp.pbpp);
-			ASSERT(off_heap->mso->next
-			       == (ProcBin *) dbg_old_oh_list_p);
-			break;
-#ifndef HYBRID
-		    case FUN_SUBTAG:
-			ASSERT(off_heap->funs == *oh_list_pp.efpp);
-			ASSERT(off_heap->funs->next
-			       == (ErlFunThing *) dbg_old_oh_list_p);
-			break;
-#endif
-		    case EXTERNAL_PID_SUBTAG:
-		    case EXTERNAL_PORT_SUBTAG:
-		    case EXTERNAL_REF_SUBTAG:
-			ASSERT(off_heap->externals
-			       == *oh_list_pp.etpp);
-			ASSERT(off_heap->externals->next
-			       == (ExternalThing *) dbg_old_oh_list_p);
-			break;
-		    default:
-			ASSERT(0);
-		    }
-#endif
-		    oh_list_pp.upp = NULL;
-
-
+		    oh->next = off_heap->first;
+		    off_heap->first = oh;
+		    ASSERT(*hpp <= (Eterm*)oh);
+		    ASSERT(hp > (Eterm*)oh);
+		    oh = NULL;
 		}
 		break;
 	    }
@@ -765,11 +692,7 @@ copy_done:
 #endif
 	    
 
-    bp->off_heap.mso = NULL;
-#ifndef HYBRID
-    bp->off_heap.funs = NULL;
-#endif
-    bp->off_heap.externals = NULL;
+    bp->off_heap.first = NULL;
     free_message_buffer(bp);
     msg->data.heap_frag = NULL;
 
diff --git a/erts/emulator/beam/erl_message.h b/erts/emulator/beam/erl_message.h
index f478572ac2..890af2675c 100644
--- a/erts/emulator/beam/erl_message.h
+++ b/erts/emulator/beam/erl_message.h
@@ -28,13 +28,18 @@ struct external_thing_;
  * but is stored outside of any heap.
  */
 
+struct erl_off_heap_header {
+    Eterm thing_word;
+    union {
+	Uint size;
+	void* ptr;
+    }u;
+    struct erl_off_heap_header* next;
+};
+
 typedef struct erl_off_heap {
-    struct proc_bin* mso;	/* List of associated binaries. */
-#ifndef HYBRID /* FIND ME! */
-    struct erl_fun_thing* funs;	/* List of funs. */
-#endif
-    struct external_thing_* externals; /* List of external things. */
-    int overhead;		/* Administrative overhead (used to force GC). */
+    struct erl_off_heap_header* first;
+    int overhead;     /* Administrative overhead (used to force GC). */
 } ErlOffHeap;
 
 #include "external.h"
@@ -201,9 +206,7 @@ do {							\
     (HEAP_FRAG_P)->next = NULL;				\
     (HEAP_FRAG_P)->alloc_size = (DATA_WORDS);		\
     (HEAP_FRAG_P)->used_size = (DATA_WORDS);            \
-    (HEAP_FRAG_P)->off_heap.mso = NULL;			\
-    (HEAP_FRAG_P)->off_heap.funs = NULL;		\
-    (HEAP_FRAG_P)->off_heap.externals = NULL;		\
+    (HEAP_FRAG_P)->off_heap.first = NULL; 	        \
     (HEAP_FRAG_P)->off_heap.overhead = 0;		\
 } while (0)
 
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 3d63fa1caf..e95d9c4f75 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -258,9 +258,7 @@ void enif_free_env(ErlNifEnv* env)
 
 static ERTS_INLINE void clear_offheap(ErlOffHeap* oh)
 {
-    oh->mso = NULL;
-    oh->externals = NULL;
-    oh->funs = NULL;
+    oh->first = NULL;
     oh->overhead = 0;
 }
 
@@ -364,7 +362,7 @@ ERL_NIF_TERM enif_make_copy(ErlNifEnv* dst_env, ERL_NIF_TERM src_term)
 #ifdef DEBUG
 static int is_offheap(const ErlOffHeap* oh)
 {
-    return oh->mso != NULL || oh->funs != NULL || oh->externals != NULL;
+    return oh->first != NULL;
 }
 #endif
 
@@ -627,8 +625,8 @@ Eterm enif_make_binary(ErlNifEnv* env, ErlNifBinary* bin)
 	pb = (ProcBin *) alloc_heap(env, PROC_BIN_SIZE);
 	pb->thing_word = HEADER_PROC_BIN;
 	pb->size = bptr->orig_size;
-	pb->next = MSO(env->proc).mso;
-	MSO(env->proc).mso = pb;
+	pb->next = MSO(env->proc).first;
+	MSO(env->proc).first = (struct erl_off_heap_header*) pb;
 	pb->val = bptr;
 	pb->bytes = (byte*) bptr->orig_bytes;
 	pb->flags = 0;
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 5865d33138..7482da251e 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -1087,30 +1087,24 @@ insert_offheap2(ErlOffHeap *oh, void *arg)
 static void
 insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 {
-    if(oh->externals) {
-	ExternalThing *etp = oh->externals;
-	while (etp) {
-	    insert_node(etp->node, type, id);
-	    etp = etp->next;
-	}
-    }
+    union erl_off_heap_ptr u;
+    struct insert_offheap2_arg a;
+    a.type = BIN_REF;
 
-    if(oh->mso) {
-	ProcBin *pb;
-	struct insert_offheap2_arg a;
-	a.type = BIN_REF;
-	for(pb = oh->mso; pb; pb = pb->next) {
-	    if(IsMatchProgBinary(pb->val)) {
+    for (u.hdr = oh->first; u.hdr; u.hdr = u.hdr->next) {
+	switch (thing_subtag(u.hdr->thing_word)) {
+	case REFC_BINARY_SUBTAG:
+	    if(IsMatchProgBinary(u.pb->val)) {
 		InsertedBin *ib;
 		int insert_bin = 1;
 		for (ib = inserted_bins; ib; ib = ib->next)
-		    if(ib->bin_val == pb->val) {
+		    if(ib->bin_val == u.pb->val) {
 			insert_bin = 0;
 			break;
 		    }
 		if (insert_bin) {
 #if HALFWORD_HEAP
-		    UWord val = (UWord) pb->val;
+		    UWord val = (UWord) u.pb->val;
 		    DeclareTmpHeapNoproc(id_heap,BIG_UINT_HEAP_SIZE*2); /* extra place allocated */
 #else
 		    DeclareTmpHeapNoproc(id_heap,BIG_UINT_HEAP_SIZE);
@@ -1124,13 +1118,13 @@ insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 		    a.id = erts_bld_uword(&hp, NULL, (UWord) val);
 #else
 		    UseTmpHeapNoproc(BIG_UINT_HEAP_SIZE);
-		    a.id = erts_bld_uint(&hp, NULL, (Uint) pb->val);
+		    a.id = erts_bld_uint(&hp, NULL, (Uint) u.pb->val);
 #endif
-		    erts_match_prog_foreach_offheap(pb->val,
+		    erts_match_prog_foreach_offheap(u.pb->val,
 						    insert_offheap2,
 						    (void *) &a);
 		    nib = erts_alloc(ERTS_ALC_T_NC_TMP, sizeof(InsertedBin));
-		    nib->bin_val = pb->val;
+		    nib->bin_val = u.pb->val;
 		    nib->next = inserted_bins;
 		    inserted_bins = nib;
 #if HALFWORD_HEAP
@@ -1139,15 +1133,16 @@ insert_offheap(ErlOffHeap *oh, int type, Eterm id)
 		    UnUseTmpHeapNoproc(BIG_UINT_HEAP_SIZE);
 #endif
 		}
-	    }
+	    }		
+	    break;
+	case FUN_SUBTAG:
+	    break; /* No need to */
+	default:
+	    ASSERT(is_external_header(u.hdr->thing_word));
+	    insert_node(u.ext->node, type, id);
+	    break;
 	}
     }
-
-#if 0
-    if(oh->funs) {
-	/* No need to */
-    }
-#endif
 }
 
 static void doit_insert_monitor(ErtsMonitor *monitor, void *p)
@@ -1289,6 +1284,7 @@ setup_reference_table(void)
     for (i = 0; i < erts_max_processes; i++)
 	if (process_tab[i]) {
 	    ErlMessage *msg;
+
 	    /* Insert Heap */
 	    insert_offheap(&(process_tab[i]->off_heap),
 			   HEAP_REF,
@@ -1375,21 +1371,22 @@ setup_reference_table(void)
 
     { /* Add binaries stored elsewhere ... */
 	ErlOffHeap oh;
-	ProcBin pb[2] = {{0},{0}};
-	ProcBin *mso = NULL;
+	ProcBin pb[2];
 	int i = 0;
 	Binary *default_match_spec;
 	Binary *default_meta_match_spec;
 
-	/* Only the ProcBin members val and next will be inspected
+	oh.first = NULL;
+	/* Only the ProcBin members thing_word, val and next will be inspected
 	   (by insert_offheap()) */
 #undef  ADD_BINARY
-#define ADD_BINARY(Bin)					\
-	if ((Bin)) {					\
-	    pb[i].val = (Bin);				\
-	    pb[i].next = mso;				\
-	    mso = &pb[i];				\
-	    i++;					\
+#define ADD_BINARY(Bin)				 	     \
+	if ((Bin)) {					     \
+	    pb[i].thing_word = REFC_BINARY_SUBTAG;           \
+	    pb[i].val = (Bin);				     \
+	    pb[i].next = oh.first;		             \
+	    oh.first = (struct erl_off_heap_header*) &pb[i]; \
+	    i++;				             \
 	}
 
 	erts_get_default_trace_pattern(NULL,
@@ -1401,11 +1398,6 @@ setup_reference_table(void)
 	ADD_BINARY(default_match_spec);
 	ADD_BINARY(default_meta_match_spec);
 
-	oh.mso = mso;
-	oh.externals = NULL;
-#ifndef HYBRID /* FIND ME! */
-	oh.funs = NULL;
-#endif
 	insert_offheap(&oh, BIN_REF, AM_match_spec);
 #undef  ADD_BINARY
     }
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 41031f5468..8c88353593 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -6761,11 +6761,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     /*
      * Must initialize binary lists here before copying binaries to process.
      */
-    p->off_heap.mso = NULL;
-#ifndef HYBRID /* FIND ME! */
-    p->off_heap.funs = NULL;
-#endif
-    p->off_heap.externals = NULL;
+    p->off_heap.first = NULL;
     p->off_heap.overhead = 0;
 
     heap_need +=
@@ -6855,7 +6851,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	p->group_leader =
 	    IS_CONST(parent->group_leader)
 	    ? parent->group_leader
-	    : STORE_NC(&p->htop, &p->off_heap.externals, parent->group_leader);
+	    : STORE_NC(&p->htop, &p->off_heap, parent->group_leader);
     }
 
     erts_get_default_tracing(&p->trace_flags, &p->tracer_proc);
@@ -7056,11 +7052,7 @@ void erts_init_empty_process(Process *p)
     memset(&(p->u.tm), 0, sizeof(ErlTimer));
 #endif
     p->next = NULL;
-    p->off_heap.mso = NULL;
-#ifndef HYBRID /* FIND ME! */
-    p->off_heap.funs = NULL;
-#endif
-    p->off_heap.externals = NULL;
+    p->off_heap.first = NULL;
     p->off_heap.overhead = 0;
     p->reg = NULL;
     p->heap_sz = 0;
@@ -7207,11 +7199,7 @@ erts_debug_verify_clean_empty_process(Process* p)
 
     /* Thing that erts_cleanup_empty_process() cleans up */
 
-    ASSERT(p->off_heap.mso == NULL);
-#ifndef HYBRID /* FIND ME! */
-    ASSERT(p->off_heap.funs == NULL);
-#endif
-    ASSERT(p->off_heap.externals == NULL);
+    ASSERT(p->off_heap.first == NULL);
     ASSERT(p->off_heap.overhead == 0);
 
     ASSERT(p->mbuf == NULL);
@@ -7225,11 +7213,7 @@ erts_cleanup_empty_process(Process* p)
     /* We only check fields that are known to be used... */
 
     erts_cleanup_offheap(&p->off_heap);
-    p->off_heap.mso = NULL;
-#ifndef HYBRID /* FIND ME! */
-    p->off_heap.funs = NULL;
-#endif
-    p->off_heap.externals = NULL;
+    p->off_heap.first = NULL;
     p->off_heap.overhead = 0;
 
     if (p->mbuf != NULL) {
@@ -7266,7 +7250,7 @@ delete_process(Process* p)
      * The mso list should not be used anymore, but if it is, make sure that
      * we'll notice.
      */
-    p->off_heap.mso = (void *) 0x8DEFFACD;
+    p->off_heap.first = (void *) 0x8DEFFACD;
 
     if (p->arg_reg != p->def_arg_reg) {
 	erts_free(ERTS_ALC_T_ARG_REG, p->arg_reg);
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 8f9f7f004e..6ce74a917f 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -828,7 +828,7 @@ extern struct erts_system_profile_flags_t erts_system_profile_flags;
 #define F_INSLPQUEUE         (1 <<  1) /* Set if in timer queue */
 #define F_TIMO               (1 <<  2) /* Set if timeout */
 #define F_HEAP_GROW          (1 <<  3)
-#define F_NEED_FULLSWEEP     (1 <<  4) /* If process has old binaries & funs. */
+#define F_NEED_FULLSWEEP     (1 <<  4)
 #define F_USING_DB           (1 <<  5) /* If have created tables */
 #define F_DISTRIBUTION       (1 <<  6) /* Process used in distribution */
 #define F_USING_DDLL         (1 <<  7) /* Process has used the DDLL interface */
diff --git a/erts/emulator/beam/erl_term.h b/erts/emulator/beam/erl_term.h
index 3a8c30fe6a..0fb2362abd 100644
--- a/erts/emulator/beam/erl_term.h
+++ b/erts/emulator/beam/erl_term.h
@@ -857,8 +857,8 @@ _ET_DECLARE_CHECKED(struct erl_node_*,internal_ref_node,Eterm)
 typedef struct external_thing_ {
     /*                                 ----+                        */
     Eterm                   header;     /* |                        */
-    struct external_thing_ *next;       /*  > External thing head   */
-    struct erl_node_       *node;       /* |                        */
+    struct erl_node_*       node;       /*  > External thing head   */
+    struct erl_off_heap_header* next;   /* |                        */
     /*                                 ----+                        */
     union {
 	Uint32              ui32[1];
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 466165f26f..310a83200b 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -1468,11 +1468,11 @@ dec_pid(ErtsDistExternal *edep, Eterm** hpp, byte* ep, ErlOffHeap* off_heap, Ete
 	*hpp += EXTERNAL_THING_HEAD_SIZE + 1;
 
 	etp->header = make_external_pid_header(1);
-	etp->next = off_heap->externals;
+	etp->next = off_heap->first;
 	etp->node = node;
 	etp->data.ui[0] = data;
 
-	off_heap->externals = etp;
+	off_heap->first = (struct erl_off_heap_header*) etp;
 	*objp = make_external_pid(etp);
     }
     return ep;
@@ -1910,69 +1910,30 @@ is_external_string(Eterm list, int* p_is_string)
     return len;
 }
 
-/* Assumes that the ones to undo are preluding the lists. */ 
+/* Assumes that the ones to undo are preluding the list. */ 
 static void
 undo_offheap_in_area(ErlOffHeap* off_heap, Eterm* start, Eterm* end)
 {
     const Uint area_sz = (end - start) * sizeof(Eterm);
-    struct proc_bin* mso;
-    struct proc_bin** mso_nextp = NULL;
-#ifndef HYBRID /* FIND ME! */
-    struct erl_fun_thing* funs;
-    struct erl_fun_thing** funs_nextp = NULL;
-#endif
-    struct external_thing_* ext;
-    struct external_thing_** ext_nextp = NULL;
-
-    for (mso = off_heap->mso; ; mso=mso->next) {
-	if (!in_area(mso, start, area_sz)) {
-	    if (mso_nextp != NULL) {
-		*mso_nextp = NULL;
-		erts_cleanup_mso(off_heap->mso);
-		off_heap->mso = mso;
+    struct erl_off_heap_header* hdr;
+    struct erl_off_heap_header** hdr_nextp = NULL;
+
+    for (hdr = off_heap->first; ; hdr=hdr->next) {
+	if (!in_area(hdr, start, area_sz)) {
+	    if (hdr_nextp != NULL) {
+		*hdr_nextp = NULL;
+		erts_cleanup_offheap(off_heap);
+		off_heap->first = hdr;
 	    }
 	    break;
 	}
-	mso_nextp = &mso->next;
+	hdr_nextp = &hdr->next;
     }    
 
-#ifndef HYBRID /* FIND ME! */
-    for (funs = off_heap->funs; ; funs=funs->next) {
-	if (!in_area(funs, start, area_sz)) {
-	    if (funs_nextp != NULL) {
-		*funs_nextp = NULL;
-		erts_cleanup_funs(off_heap->funs);
-		off_heap->funs = funs;
-	    }
-	    break;
-	}
-	funs_nextp = &funs->next;
-    }    
-#endif
-    for (ext = off_heap->externals; ; ext=ext->next) {
-	if (!in_area(ext, start, area_sz)) {
-	    if (ext_nextp != NULL) {
-		*ext_nextp = NULL;
-		erts_cleanup_externals(off_heap->externals);
-		off_heap->externals = ext;
-	    }
-	    break;
-	}
-	ext_nextp = &ext->next;
-    }
-
-    /* Assert that the ones to undo were indeed preluding the lists. */ 
+    /* Assert that the ones to undo were indeed preluding the list. */ 
 #ifdef DEBUG
-    for (mso = off_heap->mso; mso != NULL; mso=mso->next) {
-	ASSERT(!in_area(mso, start, area_sz));
-    }    
-# ifndef HYBRID /* FIND ME! */
-    for (funs = off_heap->funs; funs != NULL; funs=funs->next) {
-	ASSERT(!in_area(funs, start, area_sz));
-    }    
-# endif
-    for (ext = off_heap->externals; ext != NULL; ext=ext->next) {
-	ASSERT(!in_area(ext, start, area_sz));
+    for (hdr = off_heap->first; hdr != NULL; hdr = hdr->next) {
+	ASSERT(!in_area(hdr, start, area_sz));
     }    
 #endif /* DEBUG */
 }
@@ -2216,11 +2177,11 @@ dec_term_atom_common:
 		    hp += EXTERNAL_THING_HEAD_SIZE + 1;
 		    
 		    etp->header = make_external_port_header(1);
-		    etp->next = off_heap->externals;
+		    etp->next = off_heap->first;
 		    etp->node = node;
 		    etp->data.ui[0] = num;
 
-		    off_heap->externals = etp;
+		    off_heap->first = (struct erl_off_heap_header*)etp;
 		    *objp = make_external_port(etp);
 		}
 
@@ -2298,10 +2259,10 @@ dec_term_atom_common:
 #else
 		    etp->header = make_external_ref_header(ref_words);
 #endif
-		    etp->next = off_heap->externals;
+		    etp->next = off_heap->first;
 		    etp->node = node;
 
-		    off_heap->externals = etp;
+		    off_heap->first = (struct erl_off_heap_header*)etp;
 		    *objp = make_external_ref(etp);
 		    ref_num = &(etp->data.ui32[0]);
 		}
@@ -2344,8 +2305,8 @@ dec_term_atom_common:
 		    hp += PROC_BIN_SIZE;
 		    pb->thing_word = HEADER_PROC_BIN;
 		    pb->size = n;
-		    pb->next = off_heap->mso;
-		    off_heap->mso = pb;
+		    pb->next = off_heap->first;
+		    off_heap->first = (struct erl_off_heap_header*)pb;
 		    pb->val = dbin;
 		    pb->bytes = (byte*) dbin->orig_bytes;
 		    pb->flags = 0;
@@ -2381,8 +2342,8 @@ dec_term_atom_common:
 		    pb = (ProcBin *) hp;
 		    pb->thing_word = HEADER_PROC_BIN;
 		    pb->size = n;
-		    pb->next = off_heap->mso;
-		    off_heap->mso = pb;
+		    pb->next = off_heap->first;
+		    off_heap->first = (struct erl_off_heap_header*)pb;
 		    pb->val = dbin;
 		    pb->bytes = (byte*) dbin->orig_bytes;
 		    pb->flags = 0;
@@ -2502,8 +2463,8 @@ dec_term_atom_common:
 		 * It is safe to link the fun into the fun list only when
 		 * no more validity tests can fail.
 		 */
-		funp->next = off_heap->funs;
-		off_heap->funs = funp;
+		funp->next = off_heap->first;
+		off_heap->first = (struct erl_off_heap_header*)funp;
 #endif
 
 		funp->fe = erts_put_fun_entry2(module, old_uniq, old_index,
@@ -2580,8 +2541,8 @@ dec_term_atom_common:
 		 * It is safe to link the fun into the fun list only when
 		 * no more validity tests can fail.
 		 */
-		funp->next = off_heap->funs;
-		off_heap->funs = funp;
+		funp->next = off_heap->first;
+		off_heap->first = (struct erl_off_heap_header*)funp;
 #endif
 		old_uniq = unsigned_val(temp);
 
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index b4a7a22082..607d3cd14c 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -464,7 +464,10 @@ typedef union {
 typedef struct proc_bin {
     Eterm thing_word;		/* Subtag REFC_BINARY_SUBTAG. */
     Uint size;			/* Binary size in bytes. */
-    struct proc_bin *next;	/* Pointer to next ProcBin. */
+#if HALFWORD_HEAP
+    char alignment__[SIZEOF_VOID_P - ERTS_SIZEOF_ETERM];
+#endif
+    struct erl_off_heap_header *next;
     Binary *val;		/* Pointer to Binary structure. */
     byte *bytes;		/* Pointer to the actual data bytes. */
     Uint flags;			/* Flag word. */
@@ -494,8 +497,8 @@ erts_mk_magic_binary_term(Eterm **hpp, ErlOffHeap *ohp, Binary *mbp)
 
     pb->thing_word = HEADER_PROC_BIN;
     pb->size = 0;
-    pb->next = ohp->mso;
-    ohp->mso = pb;
+    pb->next = ohp->first;
+    ohp->first = (struct erl_off_heap_header*) pb;
     pb->val = mbp;
     pb->bytes = (byte *) mbp->orig_bytes;
     pb->flags = 0;
@@ -512,6 +515,15 @@ erts_mk_magic_binary_term(Eterm **hpp, ErlOffHeap *ohp, Binary *mbp)
    && (thing_subtag(*binary_val((T))) == REFC_BINARY_SUBTAG) \
    && (((ProcBin *) binary_val((T)))->val->flags & BIN_FLAG_MAGIC))
 
+
+union erl_off_heap_ptr {
+    struct erl_off_heap_header* hdr;
+    ProcBin *pb;
+    struct erl_fun_thing* fun;
+    struct external_thing_* ext;
+    Eterm* ep;
+};
+
 /* arrays that get malloced at startup */
 extern Port* erts_port;
 extern erts_smp_atomic_t erts_ports_alive;
@@ -823,7 +835,6 @@ Eterm erts_new_heap_binary(Process *p, byte *buf, int len, byte** datap);
 Eterm erts_new_mso_binary(Process*, byte*, int);
 Eterm new_binary(Process*, byte*, int);
 Eterm erts_realloc_binary(Eterm bin, size_t size);
-void erts_cleanup_mso(ProcBin* pb);
 
 /* erl_bif_info.c */
 
@@ -1499,7 +1510,6 @@ void p_slpq(_VOID_);
 void erts_silence_warn_unused_result(long unused);
 
 void erts_cleanup_offheap(ErlOffHeap *offheap);
-void erts_cleanup_externals(ExternalThing *);
 
 Uint erts_fit_in_bits(Uint);
 int list_length(Eterm);
@@ -1532,7 +1542,7 @@ erts_bld_atom_2uint_3tup_list(Uint **hpp, Uint *szp, Sint length,
 			      Eterm atoms[], Uint uints1[], Uint uints2[]);
 
 Eterm store_external_or_ref_in_proc_(Process *, Eterm);
-Eterm store_external_or_ref_(Uint **, ExternalThing **, Eterm);
+Eterm store_external_or_ref_(Uint **, ErlOffHeap*, Eterm);
 
 #define NC_HEAP_SIZE(NC) \
  (ASSERT_EXPR(is_node_container((NC))), \
@@ -1957,5 +1967,5 @@ erts_alloc_message_heap(Uint size,
 #  define UnUseTmpHeap(Size,Proc) /* Nothing */
 #  define UseTmpHeapNoproc(Size) /* Nothing */
 #  define UnUseTmpHeapNoproc(Size) /* Nothing */
-#endif
-#endif
+#endif /* HEAP_ON_C_STACK */
+#endif /* !__GLOBAL_H__ */
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 68625801cf..b840f65cdd 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -1575,8 +1575,8 @@ static void deliver_read_message(Port* prt, Eterm to,
 	pb = (ProcBin *) hp;
 	pb->thing_word = HEADER_PROC_BIN;
 	pb->size = len;
-	pb->next = ohp->mso;
-	ohp->mso = pb;
+	pb->next = ohp->first;
+	ohp->first = (struct erl_off_heap_header*)pb;
 	pb->val = bptr;
 	pb->bytes = (byte*) bptr->orig_bytes;
 	pb->flags = 0;
@@ -1725,8 +1725,8 @@ deliver_vec_message(Port* prt,			/* Port */
 	    }
 	    pb->thing_word = HEADER_PROC_BIN;
 	    pb->size = iov->iov_len;
-	    pb->next = ohp->mso;
-	    ohp->mso = pb;
+	    pb->next = ohp->first;
+	    ohp->first = (struct erl_off_heap_header*)pb;
 	    pb->val = ErlDrvBinary2Binary(b);
 	    pb->bytes = base;
 	    pb->flags = 0;
@@ -2259,8 +2259,8 @@ erts_port_control(Process* p, Port* prt, Uint command, Eterm iolist)
 		ProcBin* pb = (ProcBin *) HAlloc(p, PROC_BIN_SIZE);
 		pb->thing_word = HEADER_PROC_BIN;
 		pb->size = dbin->orig_size;
-		pb->next = MSO(p).mso;
-		MSO(p).mso = pb;
+		pb->next = MSO(p).first;
+		MSO(p).first = (struct erl_off_heap_header*)pb;
 		pb->val = ErlDrvBinary2Binary(dbin);
 		pb->bytes = (byte*) dbin->orig_bytes;
 		pb->flags = 0;
@@ -3033,8 +3033,8 @@ driver_deliver_term(ErlDrvPort port,
 		driver_binary_inc_refc(b);  /* caller will free binary */
 		pb->thing_word = HEADER_PROC_BIN;
 		pb->size = size;
-		pb->next = ohp->mso;
-		ohp->mso = pb;
+		pb->next = ohp->first;
+		ohp->first = (struct erl_off_heap_header*)pb;
 		pb->val = ErlDrvBinary2Binary(b);
 		pb->bytes = ((byte*) b->orig_bytes) + offset;
 		pb->flags = 0;
@@ -3072,8 +3072,8 @@ driver_deliver_term(ErlDrvPort port,
 		hp += PROC_BIN_SIZE;
 		pbp->thing_word = HEADER_PROC_BIN;
 		pbp->size = size;
-		pbp->next = ohp->mso;
-		ohp->mso = pbp;
+		pbp->next = ohp->first;
+		ohp->first = (struct erl_off_heap_header*)pbp;
 		pbp->val = bp;
 		pbp->bytes = (byte*) bp->orig_bytes;
 		pbp->flags = 0;
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index b8d407f5e5..25472ef47a 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -162,13 +162,8 @@ erts_heap_alloc(Process* p, Uint need)
     bp->alloc_size = n;
     bp->used_size = n;
     MBUF_SIZE(p) += n;
-    bp->off_heap.mso = NULL;
-#ifndef HYBRID /* FIND ME! */
-    bp->off_heap.funs = NULL;
-#endif
-    bp->off_heap.externals = NULL;
+    bp->off_heap.first = NULL;
     bp->off_heap.overhead = 0;
-
     return bp->mem;
 }
 
@@ -2729,21 +2724,8 @@ not_equal:
 }
 
 
-void
-erts_cleanup_externals(ExternalThing *etp)
-{
-    ExternalThing *tetp;
-
-    tetp = etp;
-
-    while(tetp) {
-	erts_deref_node_entry(tetp->node);
-	tetp = tetp->next;
-    }
-}
-
 Eterm
-store_external_or_ref_(Uint **hpp, ExternalThing **etpp, Eterm ns)
+store_external_or_ref_(Uint **hpp, ErlOffHeap* oh, Eterm ns)
 {
     Uint i;
     Uint size;
@@ -2762,8 +2744,8 @@ store_external_or_ref_(Uint **hpp, ExternalThing **etpp, Eterm ns)
 
 	erts_refc_inc(&((ExternalThing *) to_hp)->node->refc, 2);
 
-	((ExternalThing *) to_hp)->next = *etpp;
-	*etpp = (ExternalThing *) to_hp;
+	((struct erl_off_heap_header*) to_hp)->next = oh->first;
+	oh->first = (struct erl_off_heap_header*) to_hp;
 
 	return make_external(to_hp);
     }
@@ -2792,7 +2774,7 @@ store_external_or_ref_in_proc_(Process *proc, Eterm ns)
     sz = NC_HEAP_SIZE(ns);
     ASSERT(sz > 0);
     hp = HAlloc(proc, sz);
-    return store_external_or_ref_(&hp, &MSO(proc).externals, ns);
+    return store_external_or_ref_(&hp, &MSO(proc), ns);
 }
 
 void bin_write(int to, void *to_arg, byte* buf, int sz)