erts: Replace meta_pid_to{_fixed}_tab with linked lists

from process psd through all owned/fixed tables.

As meta_pid_to{_fixed}_tab maps to slot in meta_main_tab
which is planned for destruction.

In this commit we no longer seize table lock while
freeing the table (free_table_cont) as it's not needed
and makes the code a bit simpler. Any concurrent operation
on the table will only access lock, owner and status
and then bail out.

10 files changed, 545 insertions, 767 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 06a73ffea5..025f99330a 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -3634,10 +3634,6 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 	    BIF_RET(TUPLE2(hp, make_small((Uint) words),
                            erts_ets_hash_sizeof_ext_segtab()));
 	}
-        else if (ERTS_IS_ATOM_STR("DbTable_meta", BIF_ARG_1)) {
-            /* Used by ets_SUITE (stdlib) */
-            BIF_RET(erts_ets_get_meta_state(BIF_P));
-        }
 	else if (ERTS_IS_ATOM_STR("check_io_debug", BIF_ARG_1)) {
 	    /* Used by driver_SUITE (emulator) */
 	    Uint sz, *szp;
@@ -4398,10 +4394,6 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
             }
             BIF_RET(am_ok);
         }
-        else if (ERTS_IS_ATOM_STR("DbTable_meta", BIF_ARG_1)) {
-            /* Used by ets_SUITE (stdlib) */
-            BIF_RET(erts_ets_restore_meta_state(BIF_P, BIF_ARG_2));
-        }
         else if (ERTS_IS_ATOM_STR("make", BIF_ARG_1)) {
             if (ERTS_IS_ATOM_STR("magic_ref", BIF_ARG_2)) {
                 Binary *bin = erts_create_magic_binary(0, empty_magic_ref_destructor);
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 8c4c76e187..24de21cc24 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -19,9 +19,7 @@
  */
 
 /*
- * This file contains the bif interface functions and
- * the handling of the "meta tables" ie the tables of 
- * db tables.
+ * This file contains the 'ets' bif interface functions.
  */
 
 /*
@@ -75,6 +73,113 @@ enum DbIterSafety {
 
 #define DID_TRAP(P,Ret) (!is_value(Ret) && ((P)->freason == TRAP))
 
+/*
+ * "fixed_tabs": list of all fixed tables for a process
+ */
+#ifdef DEBUG
+static int fixed_tabs_find(DbFixation* first, DbFixation* fix);
+#endif
+
+static void fixed_tabs_insert(Process* p, DbFixation* fix)
+{
+    DbFixation* first = erts_psd_get(p, ERTS_PSD_ETS_FIXED_TABLES);
+
+    if (!first) {
+        fix->tabs.next = fix->tabs.prev = fix;
+        erts_psd_set(p, ERTS_PSD_ETS_FIXED_TABLES, fix);
+    }
+    else {
+        ASSERT(!fixed_tabs_find(first, fix));
+        fix->tabs.prev = first->tabs.prev;
+        fix->tabs.next = first;
+        fix->tabs.prev->tabs.next = fix;
+        first->tabs.prev = fix;
+    }
+}
+
+static void fixed_tabs_delete(Process *p, DbFixation* fix)
+{
+    if (fix->tabs.next == fix) {
+        DbFixation* old;
+        ASSERT(fix->tabs.prev == fix);
+        old = erts_psd_set(p, ERTS_PSD_ETS_FIXED_TABLES, NULL);
+        ASSERT(old == fix); (void)old;
+    }
+    else {
+        DbFixation *first = (DbFixation*) erts_psd_get(p, ERTS_PSD_ETS_FIXED_TABLES);
+
+        ASSERT(fixed_tabs_find(first, fix));
+        fix->tabs.prev->tabs.next = fix->tabs.next;
+        fix->tabs.next->tabs.prev = fix->tabs.prev;
+
+        if (fix == first)
+            erts_psd_set(p, ERTS_PSD_ETS_FIXED_TABLES, fix->tabs.next);
+    }
+}
+
+#ifdef DEBUG
+static int fixed_tabs_find(DbFixation* first, DbFixation* fix)
+{
+    DbFixation* p;
+
+    if (!first) {
+        first = (DbFixation*) erts_psd_get(fix->procs.p, ERTS_PSD_ETS_FIXED_TABLES);
+    }
+    p = first;
+    do {
+        if (p == fix)
+            return 1;
+        ASSERT(p->procs.p == fix->procs.p);
+        ASSERT(p->tabs.next->tabs.prev == p);
+        p = p->tabs.next;
+    } while (p != first);
+    return 0;
+}
+#endif
+
+
+/*
+ * fixing_procs: tree of all processes fixating a table
+ */
+#define ERTS_RBT_PREFIX fixing_procs
+#define ERTS_RBT_T DbFixation
+#define ERTS_RBT_KEY_T Process*
+#define ERTS_RBT_FLAGS_T int
+#define ERTS_RBT_INIT_EMPTY_TNODE(T)                    \
+    do {						\
+	(T)->procs.parent = NULL;			\
+	(T)->procs.right = NULL;				\
+	(T)->procs.left = NULL;				\
+    } while (0)
+#define ERTS_RBT_IS_RED(T)        ((T)->procs.is_red)
+#define ERTS_RBT_SET_RED(T)       ((T)->procs.is_red = 1)
+#define ERTS_RBT_IS_BLACK(T)      (!(T)->procs.is_red)
+#define ERTS_RBT_SET_BLACK(T)     ((T)->procs.is_red = 0)
+#define ERTS_RBT_GET_FLAGS(T)     ((T)->procs.is_red)
+#define ERTS_RBT_SET_FLAGS(T, F)  ((T)->procs.is_red = (F))
+#define ERTS_RBT_GET_PARENT(T)    ((T)->procs.parent)
+#define ERTS_RBT_SET_PARENT(T, P) ((T)->procs.parent = (P))
+#define ERTS_RBT_GET_RIGHT(T)     ((T)->procs.right)
+#define ERTS_RBT_SET_RIGHT(T, R)  ((T)->procs.right = (R))
+#define ERTS_RBT_GET_LEFT(T)      ((T)->procs.left)
+#define ERTS_RBT_SET_LEFT(T, L)   ((T)->procs.left = (L))
+#define ERTS_RBT_GET_KEY(T)       ((T)->procs.p)
+#define ERTS_RBT_IS_LT(KX, KY)    ((KX) < (KY))
+#define ERTS_RBT_IS_EQ(KX, KY)    ((KX) == (KY))
+
+#define ERTS_RBT_WANT_INSERT
+#define ERTS_RBT_WANT_LOOKUP
+#define ERTS_RBT_WANT_DELETE
+#define ERTS_RBT_WANT_FOREACH
+#define ERTS_RBT_WANT_FOREACH_DESTROY
+#ifdef DEBUG
+# define ERTS_RBT_WANT_LOOKUP
+#endif
+#define ERTS_RBT_UNDEF
+
+#include "erl_rbtree.h"
+
+
 
 /* 
 ** The main meta table, containing all ets tables.
@@ -148,6 +253,12 @@ make_btid(DbTable *tb)
     erts_refc_inc(&btid->refc, 1);
 }
 
+static ERTS_INLINE DbTable* btid2tab(Binary* btid)
+{
+    erts_smp_atomic_t *tbref = erts_smp_binary_to_magic_indirection(btid);
+    return (DbTable *) erts_smp_atomic_read_nob(tbref);
+}
+
 static DbTable *
 tid2tab(Eterm tid)
 {
@@ -272,8 +383,6 @@ int user_requested_db_max_tabs;
 int erts_ets_realloc_always_moves;
 int erts_ets_always_compress;
 static int db_max_tabs;
-static DbTable *meta_pid_to_tab; /* Pid mapped to owned tables */
-static DbTable *meta_pid_to_fixed_tab; /* Pid mapped to fixed tables */
 static Eterm ms_delete_all;
 static Eterm ms_delete_all_buff[8]; /* To compare with for deletion 
 				       of all objects */
@@ -286,12 +395,9 @@ static void fix_table_locked(Process* p, DbTable* tb);
 static void unfix_table_locked(Process* p,  DbTable* tb, db_lock_kind_t* kind);
 static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data);
 static void free_heir_data(DbTable*);
-static void free_fixations_locked(DbTable *tb);
+static void free_fixations_locked(Process* p, DbTable *tb);
 
-static int free_table_cont(Process *p,
-			   DbTable *tb,
-			   int first,
-			   int clean_meta_tab);
+static int free_table_cont(Process *p, DbTable *tb);
 static void print_table(fmtfn_t to, void *to_arg, int show,  DbTable* tb);
 static BIF_RETTYPE ets_select_delete_1(BIF_ALIST_1);
 static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1);
@@ -328,15 +434,6 @@ free_dbtable(void *vtb)
 	}
 	erts_fprintf(stderr, "ets: free_dbtable(%T) deleted!!!\r\n",
 		     tb->common.id);
-
-	erts_fprintf(stderr, "ets: free_dbtable: meta_pid_to_tab common.memory_size = %ld\n",
-		     erts_smp_atomic_read_nob(&meta_pid_to_tab->common.memory_size));
-	print_table(ERTS_PRINT_STDOUT, NULL, 1, meta_pid_to_tab);
-
-
-	erts_fprintf(stderr, "ets: free_dbtable: meta_pid_to_fixed_tab common.memory_size = %ld\n",
-		     erts_smp_atomic_read_nob(&meta_pid_to_fixed_tab->common.memory_size));
-	print_table(ERTS_PRINT_STDOUT, NULL, 1, meta_pid_to_fixed_tab);
 #endif
 #ifdef ERTS_SMP
 	erts_smp_rwmtx_destroy(&tb->common.rwlock);
@@ -462,6 +559,62 @@ delete_sched_table(Process *c_p, DbTable *tb)
         erts_schedule_misc_aux_work((int) sid, scheduled_remove_sched_table, tb);
 }
 
+static ERTS_INLINE void
+save_owned_table(Process *c_p, DbTable *tb)
+{
+    DbTable *first;
+
+    erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_STATUS);
+
+    first = (DbTable*) erts_psd_get(c_p, ERTS_PSD_ETS_OWNED_TABLES);
+
+    erts_smp_refc_inc(&tb->common.refc, 1);
+
+    if (!first) {
+        tb->common.owned.next = tb->common.owned.prev = tb;
+        erts_psd_set(c_p, ERTS_PSD_ETS_OWNED_TABLES, tb);
+    }
+    else {
+        tb->common.owned.prev = first->common.owned.prev;
+        tb->common.owned.next = first;
+        tb->common.owned.prev->common.owned.next = tb;
+        first->common.owned.prev = tb;
+    }
+    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_STATUS);
+}
+
+static ERTS_INLINE void
+delete_owned_table(Process *p, DbTable *tb)
+{
+    erts_smp_proc_lock(p, ERTS_PROC_LOCK_STATUS);
+    if (tb->common.owned.next == tb) {
+        DbTable* old;
+        ASSERT(tb->common.owned.prev == tb);
+        old = erts_psd_set(p, ERTS_PSD_ETS_OWNED_TABLES, NULL);
+        ASSERT(old == tb); (void)old;
+    }
+    else {
+        DbTable *first = (DbTable*) erts_psd_get(p, ERTS_PSD_ETS_OWNED_TABLES);
+#ifdef DEBUG
+        DbTable *tmp = first;
+        do {
+            if (tmp == tb) break;
+            tmp = tmp->common.owned.next;
+        } while (tmp != first);
+        ASSERT(tmp == tb);
+#endif
+        tb->common.owned.prev->common.owned.next = tb->common.owned.next;
+        tb->common.owned.next->common.owned.prev = tb->common.owned.prev;
+
+        if (tb == first)
+            erts_psd_set(p, ERTS_PSD_ETS_OWNED_TABLES, tb->common.owned.next);
+    }
+    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
+
+    table_dec_refc(tb, 1);
+}
+
+
 static ERTS_INLINE void db_init_lock(DbTable* tb, int use_frequent_read_lock,
 				     char *rwname, char* fixname)
 {
@@ -483,7 +636,6 @@ static ERTS_INLINE void db_init_lock(DbTable* tb, int use_frequent_read_lock,
 static ERTS_INLINE void db_lock(DbTable* tb, db_lock_kind_t kind)
 {
 #ifdef ERTS_SMP
-    ASSERT(tb != meta_pid_to_tab && tb != meta_pid_to_fixed_tab);
     if (tb->common.type & DB_FINE_LOCKED) {
 	if (kind == LCK_WRITE) {	   
 	    erts_smp_rwmtx_rwlock(&tb->common.rwlock);
@@ -516,8 +668,6 @@ static ERTS_INLINE void db_unlock(DbTable* tb, db_lock_kind_t kind)
      * to follow the tb pointer!
      */
 #ifdef ERTS_SMP
-    ASSERT(tb != meta_pid_to_tab && tb != meta_pid_to_fixed_tab);
-
     if (tb->common.type & DB_FINE_LOCKED) {
 	if (kind == LCK_WRITE) {
 	    ASSERT(tb->common.is_thread_safe);
@@ -543,20 +693,6 @@ static ERTS_INLINE void db_unlock(DbTable* tb, db_lock_kind_t kind)
 #endif
 }
 
-
-static ERTS_INLINE void db_meta_lock(DbTable* tb, db_lock_kind_t kind)
-{
-    ASSERT(tb == meta_pid_to_tab || tb == meta_pid_to_fixed_tab);
-    ASSERT(kind != LCK_WRITE);
-    /* As long as we only lock for READ we don't have to lock at all. */
-}
-
-static ERTS_INLINE void db_meta_unlock(DbTable* tb, db_lock_kind_t kind)
-{
-    ASSERT(tb == meta_pid_to_tab || tb == meta_pid_to_fixed_tab);
-    ASSERT(kind != LCK_WRITE);
-}
-
 static ERTS_INLINE
 DbTable* db_get_table_aux(Process *p,
 			  Eterm id,
@@ -1544,7 +1680,6 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 #ifdef DEBUG
     int cret;
 #endif
-    DeclareTmpHeap(meta_tuple,3,BIF_P);
     DbTableMethod* meth;
     erts_smp_rwmtx_t *mmtl;
 
@@ -1701,7 +1836,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 
     erts_smp_atomic_init_nob(&tb->common.nitems, 0);
 
-    tb->common.fixations = NULL;
+    tb->common.fixing_procs = NULL;
     tb->common.compress = is_compressed;
 
 #ifdef DEBUG
@@ -1774,32 +1909,15 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     }
     
     BIF_P->flags |= F_USING_DB; /* So we can remove tb if p dies */
+    save_owned_table(BIF_P, tb);
 
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
 		"ets:new(%T,%T)=%T; Process: %T, initial: %T:%T/%bpu\n",
 		 BIF_ARG_1, BIF_ARG_2, ret, BIF_P->common.id,
 		 BIF_P->u.initial[0], BIF_P->u.initial[1], BIF_P->u.initial[2]);
-	erts_fprintf(stderr, "ets: new: meta_pid_to_tab common.memory_size = %ld\n",
-		     erts_smp_atomic_read_nob(&meta_pid_to_tab->common.memory_size));
-	erts_fprintf(stderr, "ets: new: meta_pid_to_fixed_tab common.memory_size = %ld\n",
-		     erts_smp_atomic_read_nob(&meta_pid_to_fixed_tab->common.memory_size));
 #endif
 
-    UseTmpHeap(3,BIF_P);
-
-    db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-    if (db_put_hash(meta_pid_to_tab,
-		    TUPLE2(meta_tuple,
-			   BIF_P->common.id,
-			   make_small(slot)),
-		    0) != DB_ERROR_NONE) {
-	erts_exit(ERTS_ERROR_EXIT,"Could not update ets metadata.");
-    }
-    db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
-
-    UnUseTmpHeap(3,BIF_P);
-
     BIF_RET(ret);
 }
 
@@ -1929,7 +2047,6 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
     tb->common.status |= DB_DELETE;
 
     if (tb->common.owner != BIF_P->common.id) {
-	DeclareTmpHeap(meta_tuple,3,BIF_P);
 
 	/*
 	 * The table is being deleted by a process other than its owner.
@@ -1937,22 +2054,19 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
 	 * current process will be killed (e.g. by an EXIT signal), we will
 	 * now transfer the ownership to the current process.
 	 */
-	UseTmpHeap(3,BIF_P);
-	db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-	db_erase_bag_exact2(meta_pid_to_tab, tb->common.owner,
-			    make_small(tb->common.slot));
-
-	BIF_P->flags |= F_USING_DB;
-	tb->common.owner = BIF_P->common.id;
-
-	db_put_hash(meta_pid_to_tab,
-		    TUPLE2(meta_tuple,
-			   BIF_P->common.id,
-			   make_small(tb->common.slot)),
-		    0);
-	db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
-	UnUseTmpHeap(3,BIF_P);
-    }    
+
+        Process *rp = erts_proc_lookup_raw(tb->common.owner);
+        /*
+         * Process 'rp' might be exiting, but our table lock prevents it
+         * from terminating as it cannot complete erts_db_process_exiting().
+         */
+        ASSERT(!(ERTS_PSFLG_FREE & erts_smp_atomic32_read_nob(&rp->state)));
+
+        delete_owned_table(rp, tb);
+        BIF_P->flags |= F_USING_DB;
+        tb->common.owner = BIF_P->common.id;
+        save_owned_table(BIF_P, tb);
+    }
 
     tid_clear(BIF_P, tb);
 
@@ -1978,10 +2092,10 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
     free_heir_data(tb);
     tb->common.heir = am_none;
 
-    free_fixations_locked(tb);
-
-    trap = free_table_cont(BIF_P, tb, 1, 1);
+    free_fixations_locked(BIF_P, tb);
     db_unlock(tb, LCK_WRITE);
+
+    trap = free_table_cont(BIF_P, tb);
     if (trap) {
 	/*
 	 * Package the DbTable* pointer into a bignum so that it can be safely
@@ -2006,7 +2120,6 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
 {
     Process* to_proc = NULL;
     ErtsProcLocks to_locks = ERTS_PROC_LOCK_MAIN;
-    DeclareTmpHeap(buf,5,BIF_P);
     Eterm to_pid = BIF_ARG_2;
     Eterm from_pid;
     DbTable* tb = NULL;
@@ -2028,18 +2141,10 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
 	goto badarg;  /* or should we be idempotent? return false maybe */
     }
 
-    UseTmpHeap(5,BIF_P);
-    db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-    db_erase_bag_exact2(meta_pid_to_tab, tb->common.owner,
-			make_small(tb->common.slot));
-
+    delete_owned_table(BIF_P, tb);
     to_proc->flags |= F_USING_DB;
     tb->common.owner = to_pid;
-
-    db_put_hash(meta_pid_to_tab,
-		TUPLE2(buf,to_pid,make_small(tb->common.slot)),
-		0);
-    db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
+    save_owned_table(to_proc, tb);
 
     db_unlock(tb,LCK_WRITE);
     send_ets_transfer_message(BIF_P, to_proc, &to_locks,
@@ -3273,7 +3378,6 @@ int erts_ets_rwmtx_spin_count = -1;
 
 void init_db(ErtsDbSpinCount db_spin_count)
 {
-    DbTable init_tb;
     int i;
     Eterm *hp;
     unsigned bits;
@@ -3379,72 +3483,6 @@ void init_db(ErtsDbSpinCount db_spin_count)
     db_initialize_hash();
     db_initialize_tree();
 
-    /*TT*/
-    /* Create meta table invertion. */
-    erts_smp_atomic_init_nob(&init_tb.common.memory_size, 0);
-    meta_pid_to_tab = (DbTable*) erts_db_alloc(ERTS_ALC_T_DB_TABLE,
-					       &init_tb,
-					       sizeof(DbTable));
-    erts_smp_atomic_init_nob(&meta_pid_to_tab->common.memory_size,
-			     erts_smp_atomic_read_nob(&init_tb.common.memory_size));
-
-    meta_pid_to_tab->common.id = NIL;
-    meta_pid_to_tab->common.btid = NULL;
-    meta_pid_to_tab->common.the_name = am_true;
-    meta_pid_to_tab->common.status = (DB_NORMAL | DB_BAG | DB_PUBLIC | DB_FINE_LOCKED);
-#ifdef ERTS_SMP
-    meta_pid_to_tab->common.type
-	= meta_pid_to_tab->common.status & ERTS_ETS_TABLE_TYPES;
-    /* Note, 'type' is *read only* from now on... */
-    meta_pid_to_tab->common.is_thread_safe = 0;
-#endif
-    meta_pid_to_tab->common.keypos = 1;
-    meta_pid_to_tab->common.owner  = NIL;
-    erts_smp_atomic_init_nob(&meta_pid_to_tab->common.nitems, 0);
-    meta_pid_to_tab->common.slot   = -1;
-    meta_pid_to_tab->common.meth   = &db_hash;
-    meta_pid_to_tab->common.compress = 0;
-
-    erts_smp_refc_init(&meta_pid_to_tab->common.fix_count, 0);
-    /* Neither rwlock or fixlock used
-    db_init_lock(meta_pid_to_tab, "meta_pid_to_tab", "meta_pid_to_tab_FIX");*/
-
-    if (db_create_hash(NULL, meta_pid_to_tab) != DB_ERROR_NONE) {
-	erts_exit(ERTS_ERROR_EXIT,"Unable to create ets metadata tables.");
-    }
-
-    erts_smp_atomic_set_nob(&init_tb.common.memory_size, 0);
-    meta_pid_to_fixed_tab = (DbTable*) erts_db_alloc(ERTS_ALC_T_DB_TABLE,
-						     &init_tb,
-						     sizeof(DbTable));
-    erts_smp_atomic_init_nob(&meta_pid_to_fixed_tab->common.memory_size,
-			     erts_smp_atomic_read_nob(&init_tb.common.memory_size));
-
-    meta_pid_to_fixed_tab->common.id = NIL;
-    meta_pid_to_fixed_tab->common.btid = NULL;
-    meta_pid_to_fixed_tab->common.the_name = am_true;
-    meta_pid_to_fixed_tab->common.status = (DB_NORMAL | DB_BAG | DB_PUBLIC | DB_FINE_LOCKED);
-#ifdef ERTS_SMP
-    meta_pid_to_fixed_tab->common.type
-	= meta_pid_to_fixed_tab->common.status & ERTS_ETS_TABLE_TYPES;
-    /* Note, 'type' is *read only* from now on... */
-    meta_pid_to_fixed_tab->common.is_thread_safe = 0;
-#endif
-    meta_pid_to_fixed_tab->common.keypos = 1;
-    meta_pid_to_fixed_tab->common.owner  = NIL;
-    erts_smp_atomic_init_nob(&meta_pid_to_fixed_tab->common.nitems, 0);
-    meta_pid_to_fixed_tab->common.slot   = -1;
-    meta_pid_to_fixed_tab->common.meth   = &db_hash;
-    meta_pid_to_fixed_tab->common.compress = 0;
-
-    erts_smp_refc_init(&meta_pid_to_fixed_tab->common.fix_count, 0);
-    /* Neither rwlock or fixlock used
-    db_init_lock(meta_pid_to_fixed_tab, "meta_pid_to_fixed_tab", "meta_pid_to_fixed_tab_FIX");*/
-
-    if (db_create_hash(NULL, meta_pid_to_fixed_tab) != DB_ERROR_NONE) {
-	erts_exit(ERTS_ERROR_EXIT,"Unable to create ets metadata tables.");
-    }
-
     /* Non visual BIF to trap to. */
     erts_init_trap_export(&ets_select_delete_continue_exp,
 			  am_ets, am_atom_put("delete_trap",11), 1,
@@ -3486,82 +3524,6 @@ erts_ets_sched_spec_data_init(ErtsSchedulerData *esdp)
 }
 
 
-#define ARRAY_CHUNK 100
-
-typedef enum {
-    ErtsDbProcCleanupProgressTables,
-    ErtsDbProcCleanupProgressFixations,
-    ErtsDbProcCleanupProgressDone,
-} ErtsDbProcCleanupProgress;
-
-typedef enum {
-    ErtsDbProcCleanupOpGetTables,
-    ErtsDbProcCleanupOpDeleteTables,
-    ErtsDbProcCleanupOpGetFixations,
-    ErtsDbProcCleanupOpDeleteFixations,
-    ErtsDbProcCleanupOpDone
-} ErtsDbProcCleanupOperation;
-
-typedef struct {
-    ErtsDbProcCleanupProgress progress;
-    ErtsDbProcCleanupOperation op;
-    struct {
-	Eterm arr[ARRAY_CHUNK];
-	int size;
-	int ix;
-	int clean_ix;
-    } slots;
-} ErtsDbProcCleanupState;
-
-
-static void
-proc_exit_cleanup_tables_meta_data(Eterm pid, ErtsDbProcCleanupState *state)
-{
-    ASSERT(state->slots.clean_ix <= state->slots.ix);
-    if (state->slots.clean_ix < state->slots.ix) {
-	db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-	if (state->slots.size < ARRAY_CHUNK
-	    && state->slots.ix == state->slots.size) {
-	    Eterm dummy;
-	    db_erase_hash(meta_pid_to_tab,pid,&dummy);
-	}
-	else {
-	    int ix;
-	    /* Need to erase each explicitly */
-	    for (ix = state->slots.clean_ix; ix < state->slots.ix; ix++)
-		db_erase_bag_exact2(meta_pid_to_tab,
-				    pid,
-				    state->slots.arr[ix]);
-	}
-	db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
-	state->slots.clean_ix = state->slots.ix;
-    }
-}
-
-static void
-proc_exit_cleanup_fixations_meta_data(Eterm pid, ErtsDbProcCleanupState *state)
-{
-    ASSERT(state->slots.clean_ix <= state->slots.ix);
-    if (state->slots.clean_ix < state->slots.ix) {
-	db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-	if (state->slots.size < ARRAY_CHUNK
-	    && state->slots.ix == state->slots.size) {
-	    Eterm dummy;
-	    db_erase_hash(meta_pid_to_fixed_tab,pid,&dummy);
-	}
-	else {
-	    int ix;
-	    /* Need to erase each explicitly */
-	    for (ix = state->slots.clean_ix; ix < state->slots.ix; ix++)
-		db_erase_bag_exact2(meta_pid_to_fixed_tab,
-				    pid,
-				    state->slots.arr[ix]);
-	}
-	db_meta_unlock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-	state->slots.clean_ix = state->slots.ix;
-    }
-}
-
 /* In: Table LCK_WRITE
 ** Return TRUE : ok, table not mine and NOT locked anymore.
 ** Return FALSE: failed, table still mine (LCK_WRITE)
@@ -3570,7 +3532,6 @@ static int give_away_to_heir(Process* p, DbTable* tb)
 {
     Process* to_proc;
     ErtsProcLocks to_locks = ERTS_PROC_LOCK_MAIN;
-    DeclareTmpHeap(buf,5,p);
     Eterm to_pid;
     UWord heir_data;
 
@@ -3614,19 +3575,12 @@ retry:
 	erts_smp_proc_unlock(to_proc, to_locks);
 	return 0; /* heir dead and pid reused, table still mine */
     }
-    UseTmpHeap(5,p);
-    db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-    db_erase_bag_exact2(meta_pid_to_tab, tb->common.owner,
-			make_small(tb->common.slot));
     
+    delete_owned_table(p, tb);
     to_proc->flags |= F_USING_DB;
     tb->common.owner = to_pid;
-    
-    db_put_hash(meta_pid_to_tab,
-		TUPLE2(buf,to_pid,make_small(tb->common.slot)),
-		0);
-    db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
-    UnUseTmpHeap(5,p);
+    save_owned_table(to_proc, tb);
+
     db_unlock(tb,LCK_WRITE);
     heir_data = tb->common.heir_data;
     if (!is_immed(heir_data)) {
@@ -3674,6 +3628,56 @@ send_ets_transfer_message(Process *c_p, Process *proc,
     erts_queue_message(proc, *locks, mp, msg, sender);
 }
 
+
+/* Auto-release fixation from exiting process */
+static void proc_cleanup_fixed_table(Process* p, DbFixation* fix)
+{
+    DbTable* tb = btid2tab(fix->tabs.btid);
+
+    ASSERT(fix->procs.p == p); (void)p;
+    if (tb) {
+	db_lock(tb, LCK_WRITE_REC);
+	if (!(tb->common.status & DB_DELETE)) {
+	    erts_aint_t diff;
+    #ifdef ERTS_SMP
+	    erts_smp_mtx_lock(&tb->common.fixlock);
+    #endif
+
+	    ASSERT(fixing_procs_rbt_lookup(tb->common.fixing_procs, p));
+
+	    diff = -((erts_aint_t) fix->counter);
+	    erts_smp_refc_add(&tb->common.fix_count,diff,0);
+	    fix->counter = 0;
+
+	    fixing_procs_rbt_delete(&tb->common.fixing_procs, fix);
+
+    #ifdef ERTS_SMP
+	    erts_smp_mtx_unlock(&tb->common.fixlock);
+    #endif
+	    if (!IS_FIXED(tb) && IS_HASH_TABLE(tb->common.status)) {
+		db_unfix_table_hash(&(tb->hash));
+	    }
+
+	    ASSERT(sizeof(DbFixation) == ERTS_ALC_DBG_BLK_SZ(fix));
+	    ERTS_DB_ALC_MEM_UPDATE_(tb, sizeof(DbFixation), 0);
+	}
+	else {
+	    ASSERT(fix->counter == 0);
+	}
+	db_unlock(tb, LCK_WRITE_REC);
+    }
+    else {
+	ASSERT(fix->counter == 0);
+    }
+
+    if (erts_refc_dectest(&fix->tabs.btid->refc, 0) == 0) {
+	erts_bin_free(fix->tabs.btid);
+    }
+    erts_free(ERTS_ALC_T_DB_FIXATION, fix);
+    ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
+}
+
+
 /*
  * erts_db_process_exiting() is called when a process terminates.
  * It returns 0 when completely done, and !0 when it wants to
@@ -3687,277 +3691,157 @@ send_ets_transfer_message(Process *c_p, Process *proc,
 int
 erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 {
-    ErtsDbProcCleanupState *state = (ErtsDbProcCleanupState *) c_p->u.terminate;
+    typedef struct {
+        enum {
+            GET_OWNED_TABLE,
+            FREE_OWNED_TABLE,
+            UNFIX_TABLES,
+        }op;
+        DbTable *tb;
+    } CleanupState;
+    CleanupState *state = (CleanupState *) c_p->u.terminate;
     Eterm pid = c_p->common.id;
-    ErtsDbProcCleanupState default_state;
-    int ret;
+    CleanupState default_state;
 
     if (!state) {
 	state = &default_state;
-	state->progress = ErtsDbProcCleanupProgressTables;
-	state->op = ErtsDbProcCleanupOpGetTables;
+	state->op = GET_OWNED_TABLE;
+        state->tb = NULL;
     }
 
-    while (!0) {
+    do {
 	switch (state->op) {
-	case ErtsDbProcCleanupOpGetTables:
-	    state->slots.size = ARRAY_CHUNK;
-	    db_meta_lock(meta_pid_to_tab, LCK_READ);
-	    ret = db_get_element_array(meta_pid_to_tab,
-				       pid,
-				       2,
-				       state->slots.arr,
-				       &state->slots.size);
-	    db_meta_unlock(meta_pid_to_tab, LCK_READ);
-	    if (ret == DB_ERROR_BADKEY) {
-		/* Done with tables; now fixations */
-		state->progress = ErtsDbProcCleanupProgressFixations;
-		state->op = ErtsDbProcCleanupOpGetFixations;
-		break;
-	    } else if (ret != DB_ERROR_NONE) {
-		ERTS_DB_INTERNAL_ERROR("Inconsistent ets table metadata");
-	    }
-
-	    state->slots.ix = 0;
-	    state->slots.clean_ix = 0;
-	    state->op = ErtsDbProcCleanupOpDeleteTables;
-	    /* Fall through */
-
-	case ErtsDbProcCleanupOpDeleteTables:
-
-	    while (state->slots.ix < state->slots.size) {
-		DbTable *tb = NULL;
-		Sint ix = unsigned_val(state->slots.arr[state->slots.ix]);
-		erts_smp_rwmtx_t *mmtl = get_meta_main_tab_lock(ix);
-		erts_smp_rwmtx_rlock(mmtl);
-		if (!IS_SLOT_FREE(ix)) {
-		    tb = GET_ANY_SLOT_TAB(ix);
-		    ASSERT(tb);
-		}
-		erts_smp_rwmtx_runlock(mmtl);
-		if (tb) {
-		    int do_yield;
-		    db_lock(tb, LCK_WRITE);
-		    /* Ownership may have changed since
-		       we looked up the table. */
-		    if (tb->common.owner != pid) {
-			do_yield = 0;
-			db_unlock(tb, LCK_WRITE);
-		    }
-		    else if (tb->common.heir != am_none
-			     && tb->common.heir != pid
-			     && give_away_to_heir(c_p, tb)) {
-			do_yield = 0;
-		    }
-		    else {
-			int first_call;
-#ifdef HARDDEBUG
-			erts_fprintf(stderr,
-				     "erts_db_process_exiting(); Table: %T, "
-				     "Process: %T\n",
-				     tb->common.id, pid);
-#endif
-			first_call = (tb->common.status & DB_DELETE) == 0;
-			if (first_call) {
-                            tid_clear(c_p, tb);
-			    /* Clear all access bits. */
-			    tb->common.status &= ~(DB_PROTECTED
-						   | DB_PUBLIC
-						   | DB_PRIVATE);
-			    tb->common.status |= DB_DELETE;
-
-			    if (is_atom(tb->common.id))
-				remove_named_tab(tb, 0);
-
-			    free_heir_data(tb);
-			    free_fixations_locked(tb);
-			}
-
-			do_yield = free_table_cont(c_p, tb, first_call, 0);
-			db_unlock(tb, LCK_WRITE);
-		    }		    
-		    if (do_yield)
-			goto yield;
-		}
-		state->slots.ix++;
-		if (ERTS_BIF_REDS_LEFT(c_p) <= 0)
-		    goto yield;
-	    }
+        case GET_OWNED_TABLE: {
+            DbTable* tb;
+            erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_STATUS);
+            tb = (DbTable*) erts_psd_get(c_p, ERTS_PSD_ETS_OWNED_TABLES);
+            erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_STATUS);
+
+            if (!tb) {
+                /* Done with owned tables; now fixations */
+                state->op = UNFIX_TABLES;
+                break;
+            }
 
-	    proc_exit_cleanup_tables_meta_data(pid, state);
-	    state->op = ErtsDbProcCleanupOpGetTables;
-	    break;
+            ASSERT(tb != state->tb);
+            state->tb = tb;
+            db_lock(tb, LCK_WRITE);
+            /*
+             *  Ownership may have changed since we looked up the table.
+             */
+            if (tb->common.owner != pid) {
+                db_unlock(tb, LCK_WRITE);
+                break;
+            }
+            if (tb->common.heir != am_none
+                && tb->common.heir != pid
+                && give_away_to_heir(c_p, tb)) {
+                break;
+            }
+            tid_clear(c_p, tb);
+            /* Clear all access bits. */
+            tb->common.status &= ~(DB_PROTECTED | DB_PUBLIC | DB_PRIVATE);
+            tb->common.status |= DB_DELETE;
+
+            if (is_atom(tb->common.id))
+                remove_named_tab(tb, 0);
+
+            free_heir_data(tb);
+            free_fixations_locked(c_p, tb);
+            db_unlock(tb, LCK_WRITE);
+            state->op = FREE_OWNED_TABLE;
+            /* fall through */
+        }
+        case FREE_OWNED_TABLE:
+            if (free_table_cont(c_p, state->tb))
+                goto yield;
 
-	case ErtsDbProcCleanupOpGetFixations:
-	    state->slots.size = ARRAY_CHUNK;
-	    db_meta_lock(meta_pid_to_fixed_tab, LCK_READ);
-	    ret = db_get_element_array(meta_pid_to_fixed_tab, 
-				       pid,
-				       2,
-				       state->slots.arr,
-				       &state->slots.size);
-	    db_meta_unlock(meta_pid_to_fixed_tab, LCK_READ);
-
-	    if (ret == DB_ERROR_BADKEY) {
-		/* Done */
-		state->progress = ErtsDbProcCleanupProgressDone;
-		state->op = ErtsDbProcCleanupOpDone;
-		break;
-	    } else if (ret != DB_ERROR_NONE) {
-		ERTS_DB_INTERNAL_ERROR("Inconsistent ets fix table metadata");
-	    }
+            state->op = GET_OWNED_TABLE;
 
-	    state->slots.ix = 0;
-	    state->slots.clean_ix = 0;
-	    state->op = ErtsDbProcCleanupOpDeleteFixations;
-	    /* Fall through */
+            break;
 
-	case ErtsDbProcCleanupOpDeleteFixations:
+	case UNFIX_TABLES: {
+	    DbFixation* fix;
 
-	    while (state->slots.ix < state->slots.size) {
-		DbTable *tb = NULL;
-		Sint ix = unsigned_val(state->slots.arr[state->slots.ix]);
-		erts_smp_rwmtx_t *mmtl = get_meta_main_tab_lock(ix);
-		erts_smp_rwmtx_rlock(mmtl);
-		if (IS_SLOT_ALIVE(ix)) {
-		    tb = meta_main_tab[ix].u.tb;
-		    ASSERT(tb);
-		}
-		erts_smp_rwmtx_runlock(mmtl);
-		if (tb) {
-		    int reds = 0;
-
-		    db_lock(tb, LCK_WRITE_REC);
-		    if (!(tb->common.status & DB_DELETE)) {
-			DbFixation** pp;
-
-			#ifdef ERTS_SMP
-			erts_smp_mtx_lock(&tb->common.fixlock);
-			#endif
-			reds = 10;
-
-			for (pp = &tb->common.fixations; *pp != NULL;
-			      pp = &(*pp)->next) {
-			    if ((*pp)->pid == pid) {
-				DbFixation* fix = *pp;
-				erts_aint_t diff = -((erts_aint_t) fix->counter);
-				erts_smp_refc_add(&tb->common.fix_count,diff,0);
-				*pp = fix->next;
-				erts_db_free(ERTS_ALC_T_DB_FIXATION,
-					     tb, fix, sizeof(DbFixation));
-				ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
-				break;
-			    }
-			}
-			#ifdef ERTS_SMP
-			erts_smp_mtx_unlock(&tb->common.fixlock);
-			#endif
-			if (!IS_FIXED(tb) && IS_HASH_TABLE(tb->common.status)) {
-			    db_unfix_table_hash(&(tb->hash));
-			    reds += 40;
-			}
-		    }
-		    db_unlock(tb, LCK_WRITE_REC);
-		    BUMP_REDS(c_p, reds);
-		}
-		state->slots.ix++;
-		if (ERTS_BIF_REDS_LEFT(c_p) <= 0)
-		    goto yield;
-	    }
+            fix = (DbFixation*) erts_psd_get(c_p, ERTS_PSD_ETS_FIXED_TABLES);
 
-	    proc_exit_cleanup_fixations_meta_data(pid, state);
-	    state->op = ErtsDbProcCleanupOpGetFixations;
-	    break;
+            if (!fix) {
+                /* Done */
 
-	case ErtsDbProcCleanupOpDone:
+                if (state != &default_state)
+                    erts_free(ERTS_ALC_T_DB_PROC_CLEANUP, state);
+                c_p->u.terminate = NULL;
+                return 0;
+            }
 
-	    if (state != &default_state)
-		erts_free(ERTS_ALC_T_DB_PROC_CLEANUP, state);
-	    c_p->u.terminate = NULL;
-	    return 0;
+            fixed_tabs_delete(c_p, fix);
+            proc_cleanup_fixed_table(c_p, fix);
 
+            BUMP_REDS(c_p, 10);
+            break;
+        }
 	default:
 	    ERTS_DB_INTERNAL_ERROR("Bad internal state");
-	}
-    }
-
- yield:
+        }
 
-    switch (state->progress) {
-    case ErtsDbProcCleanupProgressTables:
-	proc_exit_cleanup_tables_meta_data(pid, state);
-	break;
-    case ErtsDbProcCleanupProgressFixations:
-	proc_exit_cleanup_fixations_meta_data(pid, state);
-	break;
-    default:
-	break;
-    }
+    } while (ERTS_BIF_REDS_LEFT(c_p) > 0);
 
-    ASSERT(c_p->u.terminate == (void *) state
-	   || state == &default_state);
+ yield:
 
     if (state == &default_state) {
 	c_p->u.terminate = erts_alloc(ERTS_ALC_T_DB_PROC_CLEANUP,
-				      sizeof(ErtsDbProcCleanupState));
-	sys_memcpy(c_p->u.terminate,
-		   (void*) state,
-		   sizeof(ErtsDbProcCleanupState));
+				      sizeof(CleanupState));
+	sys_memcpy(c_p->u.terminate, (void*) state, sizeof(CleanupState));
     }
+    else
+        ASSERT(state == c_p->u.terminate);
 
     return !0;
 }
 
+
 /*  SMP note: table only need to be LCK_READ locked */
 static void fix_table_locked(Process* p, DbTable* tb)
 {
     DbFixation *fix;
-    DeclareTmpHeap(meta_tuple,3,p);
 
 #ifdef ERTS_SMP
     erts_smp_mtx_lock(&tb->common.fixlock);
 #endif
     erts_smp_refc_inc(&tb->common.fix_count,1);
-    fix = tb->common.fixations;
+    fix = tb->common.fixing_procs;
     if (fix == NULL) {
 	tb->common.time.monotonic
 	    = erts_get_monotonic_time(erts_proc_sched_data(p));
 	tb->common.time.offset = erts_get_time_offset();
     }
     else {
-	for (; fix != NULL; fix = fix->next) {
-	    if (fix->pid == p->common.id) {
-		++(fix->counter);
+	fix = fixing_procs_rbt_lookup(fix, p);
+	if (fix) {
+	    ASSERT(fixed_tabs_find(NULL, fix));
+	    ++(fix->counter);
+
 #ifdef ERTS_SMP
-		erts_smp_mtx_unlock(&tb->common.fixlock);
+	    erts_smp_mtx_unlock(&tb->common.fixlock);
 #endif
-		return;
-	    }
+	    return;
 	}
     }
     fix = (DbFixation *) erts_db_alloc(ERTS_ALC_T_DB_FIXATION,
 				       tb, sizeof(DbFixation));
     ERTS_ETS_MISC_MEM_ADD(sizeof(DbFixation));
-    fix->pid = p->common.id;
+    fix->tabs.btid = tb->common.btid;
+    erts_refc_inc(&fix->tabs.btid->refc, 2);
+    fix->procs.p = p;
     fix->counter = 1;
-    fix->next = tb->common.fixations;
-    tb->common.fixations = fix;
+    fixing_procs_rbt_insert(&tb->common.fixing_procs, fix);
+
 #ifdef ERTS_SMP
     erts_smp_mtx_unlock(&tb->common.fixlock);
 #endif
-    p->flags |= F_USING_DB;        
-    UseTmpHeap(3,p);
-    db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-    if (db_put_hash(meta_pid_to_fixed_tab,
-		    TUPLE2(meta_tuple,
-			   p->common.id,
-			   make_small(tb->common.slot)),
-		    0) != DB_ERROR_NONE) {
-	UnUseTmpHeap(3,p);
-	erts_exit(ERTS_ERROR_EXIT,"Could not insert ets metadata in safe_fixtable.");
-    }	
-    UnUseTmpHeap(3,p);
-    db_meta_unlock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
+    p->flags |= F_USING_DB;
+
+    fixed_tabs_insert(p, fix);
 }
 
 /* SMP note: May re-lock table 
@@ -3965,28 +3849,26 @@ static void fix_table_locked(Process* p, DbTable* tb)
 static void unfix_table_locked(Process* p,  DbTable* tb,
 			       db_lock_kind_t* kind_p)
 {
-    DbFixation** pp;
+    DbFixation* fix;
 
 #ifdef ERTS_SMP
     erts_smp_mtx_lock(&tb->common.fixlock);
 #endif
-    for (pp = &tb->common.fixations; *pp != NULL; pp = &(*pp)->next) {
-	if ((*pp)->pid == p->common.id) {
-	    DbFixation* fix = *pp;
-	    erts_smp_refc_dec(&tb->common.fix_count,0);
-	    --(fix->counter);
-	    ASSERT(fix->counter >= 0);
-	    if (fix->counter > 0) {
-		break;
-	    }
-	    *pp = fix->next;
+    fix = fixing_procs_rbt_lookup(tb->common.fixing_procs, p);
+
+    if (fix) {
+	erts_smp_refc_dec(&tb->common.fix_count,0);
+	--(fix->counter);
+	ASSERT(fix->counter >= 0);
+	if (fix->counter == 0) {
+	    fixing_procs_rbt_delete(&tb->common.fixing_procs, fix);
 #ifdef ERTS_SMP
 	    erts_smp_mtx_unlock(&tb->common.fixlock);
 #endif
-	    db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-	    db_erase_bag_exact2(meta_pid_to_fixed_tab,
-				p->common.id, make_small(tb->common.slot));
-	    db_meta_unlock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
+	    fixed_tabs_delete(p, fix);
+
+	    erts_refc_dec(&fix->tabs.btid->refc, 1);
+
 	    erts_db_free(ERTS_ALC_T_DB_FIXATION,
 			 tb, (void *) fix, sizeof(DbFixation));
 	    ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
@@ -4013,29 +3895,83 @@ unlocked:
     }
 }
 
-/* Assume that tb is WRITE locked */
-static void free_fixations_locked(DbTable *tb)
+struct free_fixations_ctx
 {
-    DbFixation *fix;
-    DbFixation *next_fix;
-
-    fix = tb->common.fixations;
-    while (fix != NULL) {
-	erts_aint_t diff = -((erts_aint_t) fix->counter);
-	erts_smp_refc_add(&tb->common.fix_count,diff,0);
-	next_fix = fix->next;
-	db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-	db_erase_bag_exact2(meta_pid_to_fixed_tab,
-			    fix->pid,
-			    make_small(tb->common.slot));
-	db_meta_unlock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
-	erts_db_free(ERTS_ALC_T_DB_FIXATION,
-		     tb, (void *) fix, sizeof(DbFixation));
-	ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
-
-	fix = next_fix;
-    }
-    tb->common.fixations = NULL;
+    Process* p;
+    DbTable* tb;
+};
+
+static void free_fixations_op(DbFixation* fix, void* vctx)
+{
+    struct free_fixations_ctx* ctx = (struct free_fixations_ctx*) vctx;
+    erts_aint_t diff;
+#ifdef DEBUG
+    DbTable* dbg_tb = btid2tab(fix->tabs.btid);
+#endif
+
+    ASSERT(!dbg_tb || dbg_tb == ctx->tb);
+    ASSERT(fix->counter > 0);
+    ASSERT(ctx->tb->common.status & DB_DELETE);
+
+    diff = -((erts_aint_t) fix->counter);
+    erts_smp_refc_add(&ctx->tb->common.fix_count, diff, 0);
+
+#ifdef ERTS_SMP
+    if (fix->procs.p != ctx->p) { /* Fixated by other process */
+        fix->counter = 0;
+
+        /* Fake memory stats for table */
+        ASSERT(sizeof(DbFixation) == ERTS_ALC_DBG_BLK_SZ(fix));
+        ERTS_DB_ALC_MEM_UPDATE_(ctx->tb, sizeof(DbFixation), 0);
+
+        erts_schedule_ets_free_fixation(fix->procs.p->common.id, fix);
+        /*
+         * Either sys task is scheduled and erts_db_execute_free_fixation()
+         * will remove 'fix' or process will exit, drop sys task and
+         * proc_cleanup_fixed_table() will remove 'fix'.
+         */
+    }
+    else
+#endif
+    {
+        fixed_tabs_delete(fix->procs.p, fix);
+
+        if (erts_refc_dectest(&fix->tabs.btid->refc, 0) == 0) {
+            erts_bin_free(fix->tabs.btid);
+        }
+
+        erts_db_free(ERTS_ALC_T_DB_FIXATION,
+		     ctx->tb, (void *) fix, sizeof(DbFixation));
+        ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
+    }
+}
+
+#ifdef ERTS_SMP
+int erts_db_execute_free_fixation(Process* p, DbFixation* fix)
+{
+    ASSERT(fix->counter == 0);
+    fixed_tabs_delete(p, fix);
+
+    if (erts_refc_dectest(&fix->tabs.btid->refc, 0) == 0) {
+        erts_bin_free(fix->tabs.btid);
+    }
+    erts_free(ERTS_ALC_T_DB_FIXATION, fix);
+    ERTS_ETS_MISC_MEM_ADD(-sizeof(DbFixation));
+    return 1;
+}
+#endif
+
+static void free_fixations_locked(Process* p, DbTable *tb)
+{
+    struct free_fixations_ctx ctx;
+
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_rwmtx_is_rwlocked(&tb->common.rwlock));
+
+    ctx.p = p;
+    ctx.tb = tb;
+    fixing_procs_rbt_foreach_destroy(&tb->common.fixing_procs,
+                                     free_fixations_op, &ctx);
+    tb->common.fixing_procs = NULL;
 }
 
 static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data)
@@ -4107,9 +4043,7 @@ static BIF_RETTYPE ets_delete_trap(BIF_ALIST_1)
 
     ASSERT(*ptr == make_pos_bignum_header(1));
 
-    db_lock(tb, LCK_WRITE);
-    trap = free_table_cont(p, tb, 0, 1);
-    db_unlock(tb, LCK_WRITE);
+    trap = free_table_cont(p, tb);
 
     if (trap) {
 	BIF_TRAP1(&ets_delete_continue_exp, p, cont);
@@ -4123,21 +4057,11 @@ static BIF_RETTYPE ets_delete_trap(BIF_ALIST_1)
 /*
  * free_table_cont() returns 0 when done and !0 when more work is needed.
  */
-static int free_table_cont(Process *p,
-			   DbTable *tb,
-			   int first,
-			   int clean_meta_tab)
+static int free_table_cont(Process *p, DbTable *tb)
 {
     Eterm result;
     erts_smp_rwmtx_t *mmtl;
 
-#ifdef HARDDEBUG
-    if (!first) {
-	erts_fprintf(stderr,"ets: free_table_cont %T (continue)\r\n",
-		     tb->common.id);
-    }
-#endif
-
     result = tb->common.meth->db_free_table_continue(tb);
 
     if (result == 0) {
@@ -4157,27 +4081,36 @@ static int free_table_cont(Process *p,
 	/* Completely done - we will not get called again. */
 	mmtl = get_meta_main_tab_lock(tb->common.slot);
 #ifdef ERTS_SMP
-	if (erts_smp_rwmtx_tryrwlock(mmtl) == EBUSY) {
-	    erts_smp_rwmtx_rwunlock(&tb->common.rwlock);
-	    erts_smp_rwmtx_rwlock(mmtl);
-	    erts_smp_rwmtx_rwlock(&tb->common.rwlock);
-	}
+        erts_smp_rwmtx_rwlock(mmtl);
 #endif
 	free_slot(tb->common.slot);
 	erts_smp_rwmtx_rwunlock(mmtl);
 
-	if (clean_meta_tab) {
-	    db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
-	    db_erase_bag_exact2(meta_pid_to_tab,tb->common.owner,
-				make_small(tb->common.slot));
-	    db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
-	}
+        delete_owned_table(p, tb);
         table_dec_refc(tb, 0);
 	BUMP_REDS(p, 100);
 	return 0;
     }
 }
 
+struct fixing_procs_info_ctx
+{
+    Process* p;
+    Eterm list;
+};
+
+static void fixing_procs_info_op(DbFixation* fix, void* vctx)
+{
+    struct fixing_procs_info_ctx* ctx = (struct fixing_procs_info_ctx*) vctx;
+    Eterm* hp;
+    Eterm tpl;
+
+    hp = HAllocX(ctx->p, 5, 100);
+    tpl = TUPLE2(hp, fix->procs.p->common.id, make_small(fix->counter));
+    hp += 3;
+    ctx->list = CONS(hp, tpl, ctx->list);
+}
+
 static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 {
     Eterm ret = THE_NON_VALUE;
@@ -4249,9 +4182,9 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 	if (IS_FIXED(tb)) {
 	    Uint need;
 	    Eterm *hp;
-	    Eterm tpl, lst;
-	    DbFixation *fix;
+	    Eterm time;
 	    Sint64 mtime;
+	    struct fixing_procs_info_ctx ctx;
 	    
 	    need = 3;
 	    if (use_monotonic) {
@@ -4264,19 +4197,15 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 		mtime = 0;
 		need += 4;
 	    }
-	    for (fix = tb->common.fixations; fix != NULL; fix = fix->next) {
-		need += 5;
-	    }
+	    ctx.p = p;
+	    ctx.list = NIL;
+	    fixing_procs_rbt_foreach(tb->common.fixing_procs,
+				     fixing_procs_info_op,
+				     &ctx);
+
 	    hp = HAlloc(p, need);
-	    lst = NIL;
-	    for (fix = tb->common.fixations; fix != NULL; fix = fix->next) {
-		tpl = TUPLE2(hp,fix->pid,make_small(fix->counter));
-		hp += 3;
-		lst = CONS(hp,tpl,lst);
-		hp += 2;
-	    }
 	    if (use_monotonic)
-		tpl = (IS_SSMALL(mtime)
+		time = (IS_SSMALL(mtime)
 		       ? make_small(mtime)
 		       : erts_sint64_to_big(mtime, &hp));
 	    else {
@@ -4284,10 +4213,10 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 		erts_make_timestamp_value(&ms, &s, &us,
 					  tb->common.time.monotonic,
 					  tb->common.time.offset);
-		tpl = TUPLE3(hp, make_small(ms), make_small(s), make_small(us));
+		time = TUPLE3(hp, make_small(ms), make_small(s), make_small(us));
 		hp += 4;
 	    }
-	    ret = TUPLE2(hp, tpl, lst);
+	    ret = TUPLE2(hp, time, ctx.list);
 	} else {
 	    ret = am_false;
 	}
@@ -4453,37 +4382,6 @@ erts_ets_colliding_names(Process* p, Eterm name, Uint cnt)
     return list;
 }
 
-/*
- * For testing only
- * Retreive meta table size state
- */
-Eterm erts_ets_get_meta_state(Process* p)
-{
-    Eterm* hp = HAlloc(p, 3);
-    return TUPLE2(hp,
-                  erts_ets_hash_get_memstate(p, &meta_pid_to_tab->hash),
-                  erts_ets_hash_get_memstate(p, &meta_pid_to_fixed_tab->hash));
-}
-/*
- * For testing only
- * Restore a previously retrieved meta table size state.
- * We do this to suppress failed memory checks
- * caused by the hysteresis of meta tables grow/shrink limits.
- */
-Eterm erts_ets_restore_meta_state(Process* p, Eterm meta_state)
-{
-    Eterm* tv;
-    Eterm* hp;
-    if (!is_tuple_arity(meta_state, 2))
-        return am_badarg;
-
-    tv = tuple_val(meta_state);
-    hp = HAlloc(p, 3);
-    return TUPLE2(hp,
-                  erts_ets_hash_restore_memstate(&meta_pid_to_tab->hash, tv[1]),
-                  erts_ets_hash_restore_memstate(&meta_pid_to_fixed_tab->hash, tv[2]));
-}
-
 #ifdef HARDDEBUG   /* Here comes some debug functions */
 
 void db_check_tables(void)
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h
index 1c53401590..cbf4b9e007 100644
--- a/erts/emulator/beam/erl_db.h
+++ b/erts/emulator/beam/erl_db.h
@@ -109,6 +109,7 @@ typedef enum {
 
 void init_db(ErtsDbSpinCount);
 int erts_db_process_exiting(Process *, ErtsProcLocks);
+int erts_db_execute_free_fixation(Process*, DbFixation*);
 void db_info(fmtfn_t, void *, int);
 void erts_db_foreach_table(void (*)(DbTable *, void *), void *);
 void erts_db_foreach_offheap(DbTable *,
@@ -125,9 +126,6 @@ extern Export ets_select_continue_exp;
 extern erts_smp_atomic_t erts_ets_misc_mem_size;
 
 Eterm erts_ets_colliding_names(Process*, Eterm name, Uint cnt);
-Eterm erts_ets_get_meta_state(Process* p);
-Eterm erts_ets_restore_meta_state(Process* p, Eterm target_state);
-
 Uint erts_db_get_max_tabs(void);
 
 #endif /* ERL_DB_H__ */
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index bb29d56aa7..3afc58bb79 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -903,70 +903,6 @@ done:
     RUNLOCK_HASH(lck);
     return DB_ERROR_NONE;
 }
-
-int db_get_element_array(DbTable *tbl, 
-			 Eterm key,
-			 int ndex, 
-			 Eterm *ret,
-			 int *num_ret)
-{
-    DbTableHash *tb = &tbl->hash;
-    HashValue hval;
-    int ix;
-    HashDbTerm* b1;
-    int num = 0;
-    int retval;
-    erts_smp_rwmtx_t* lck;
-
-    ASSERT(!IS_FIXED(tbl)); /* no support for fixed tables here */
-
-    hval = MAKE_HASH(key);
-    lck = RLOCK_HASH(tb, hval);
-    ix = hash_to_ix(tb, hval);
-    b1 = BUCKET(tb, ix);
-
-    while(b1 != 0) {
-	if (has_live_key(tb,b1,key,hval)) {
-	    if (tb->common.status & (DB_BAG | DB_DUPLICATE_BAG)) {
-		HashDbTerm* b;
-		HashDbTerm* b2 = b1->next;
-
-		while(b2 != NULL && has_live_key(tb,b2,key,hval)) {
-		    if (ndex > arityval(b2->dbterm.tpl[0])) {
-			retval = DB_ERROR_BADITEM;
-			goto done;
-		    }
-		    b2 = b2->next;
-		}
-
-		b = b1;
-		while(b != b2) {
-		    if (num < *num_ret) {
-			ret[num++] = b->dbterm.tpl[ndex];
-		    } else {
-			retval = DB_ERROR_NONE;
-			goto done;
-		    }
-		    b = b->next;
-		}
-		*num_ret = num;
-	    }
-	    else {
-		ASSERT(*num_ret > 0);
-		ret[0] = b1->dbterm.tpl[ndex];
-		*num_ret = 1;
-	    }
-	    retval = DB_ERROR_NONE;
-	    goto done;
-	}
-	b1 = b1->next;
-    }
-    retval = DB_ERROR_BADKEY;
-done:
-    RUNLOCK_HASH(lck);
-    return retval;
-}
-    
     
 static int db_member_hash(DbTable *tbl, Eterm key, Eterm *ret)
 {
@@ -1059,54 +995,6 @@ done:
 }
 
 /*
- * Very internal interface, removes elements of arity two from 
- * BAG. Used for the PID meta table
- */
-int db_erase_bag_exact2(DbTable *tbl, Eterm key, Eterm value)
-{
-    DbTableHash *tb = &tbl->hash;
-    HashValue hval;
-    int ix;
-    HashDbTerm** bp;
-    HashDbTerm* b;
-    erts_smp_rwmtx_t* lck;
-    int found = 0;
-
-    hval = MAKE_HASH(key);
-    lck = WLOCK_HASH(tb,hval);
-    ix = hash_to_ix(tb, hval);
-    bp = &BUCKET(tb, ix);
-    b = *bp;
-
-    ASSERT(!IS_FIXED(tb));
-    ASSERT((tb->common.status & DB_BAG));
-    ASSERT(!tb->common.compress);
-
-    while(b != 0) {
-	if (has_live_key(tb,b,key,hval)) {
-	    found = 1;
-	    if ((arityval(b->dbterm.tpl[0]) == 2) && 
-		EQ(value, b->dbterm.tpl[2])) {
-		*bp = b->next;
-		free_term(tb, b);
-		erts_smp_atomic_dec_nob(&tb->common.nitems);
-		b = *bp;
-		break;
-	    }
-	} else if (found) {
-		break;
-	}
-	bp = &b->next;
-	b = b->next;
-    }
-    WUNLOCK_HASH(lck);
-    if (found) {
-	try_shrink(tb);
-    }
-    return DB_ERROR_NONE;
-}
-	
-/*
 ** NB, this is for the db_erase/2 bif.
 */
 int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret)
@@ -2207,7 +2095,7 @@ static int db_free_table_continue_hash(DbTable *tbl)
     DbTableHash *tb = &tbl->hash;
     int done;
     FixedDeletion* fixdel = (FixedDeletion*) erts_smp_atomic_read_acqb(&tb->fixdel);
-    ERTS_SMP_LC_ASSERT(IS_TAB_WLOCKED(tb));
+    ERTS_SMP_LC_ASSERT(IS_TAB_WLOCKED(tb) || (tb->common.status & DB_DELETE));
 
     done = 0;
     while (fixdel != NULL) {
@@ -3007,44 +2895,6 @@ Eterm erts_ets_hash_sizeof_ext_segtab(void)
 {
     return make_small(((SIZEOF_EXT_SEGTAB(0)-1) / sizeof(UWord)) + 1);
 }
-/* For testing only */
-Eterm erts_ets_hash_get_memstate(Process* p, DbTableHash* tb)
-{
-    Eterm seg_cnt;
-    while (!begin_resizing(tb))
-        /*spinn*/;
-
-    seg_cnt = make_small(SLOT_IX_TO_SEG_IX(tb->nslots));
-    done_resizing(tb);
-    return seg_cnt;
-}
-/* For testing only */
-Eterm erts_ets_hash_restore_memstate(DbTableHash* tb, Eterm memstate)
-{
-    int seg_cnt, target;
-
-    if (!is_small(memstate))
-        return make_small(__LINE__);
-
-    target = signed_val(memstate);
-    if (target < 1)
-        return make_small(__LINE__);
-    while (1) {
-        while (!begin_resizing(tb))
-            /*spin*/;
-        seg_cnt = SLOT_IX_TO_SEG_IX(tb->nslots);
-        done_resizing(tb);
-
-        if (target == seg_cnt)
-            return am_ok;
-        if (IS_FIXED(tb))
-            return make_small(__LINE__);
-        if (target < seg_cnt)
-            shrink(tb, 0);
-        else
-            grow(tb, INT_MAX);
-    }
-}
 
 #ifdef HARDDEBUG
 
diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h
index 6d25c73549..cd02418370 100644
--- a/erts/emulator/beam/erl_db_hash.h
+++ b/erts/emulator/beam/erl_db_hash.h
@@ -88,14 +88,6 @@ int db_get_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret);
 
 int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret);
 
-int db_get_element_array(DbTable *tbl, 
-			 Eterm key,
-			 int ndex, 
-			 Eterm *ret,
-			 int *num_ret); 
-
-int db_erase_bag_exact2(DbTable *tbl, Eterm key, Eterm value);
-
 /* not yet in method table */
 int db_mark_all_deleted_hash(DbTable *tbl);
 
@@ -110,7 +102,5 @@ typedef struct {
 
 void db_calc_stats_hash(DbTableHash* tb, DbHashStats*);
 Eterm erts_ets_hash_sizeof_ext_segtab(void);
-Eterm erts_ets_hash_get_memstate(Process*, DbTableHash* tb);
-Eterm erts_ets_hash_restore_memstate(DbTableHash* tb, Eterm memstate);
 
 #endif /* _DB_HASH_H */
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 3c13035ec5..673ec80604 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -195,9 +195,20 @@ typedef struct db_table_method
 } DbTableMethod;
 
 typedef struct db_fixation {
-    Eterm pid;
+    /* Node in fixed_tabs list */
+    struct {
+        struct db_fixation *next, *prev;
+        Binary* btid;
+    } tabs;
+
+    /* Node in fixing_procs tree */
+    struct {
+        struct db_fixation *left, *right, *parent;
+        int is_red;
+        Process* p;
+    } procs;
+
     Uint counter;
-    struct db_fixation *next;
 } DbFixation;
 
 typedef struct {
@@ -217,9 +228,10 @@ typedef struct db_table_common {
     erts_smp_refc_t refc;     /* reference count of table struct */
     erts_smp_refc_t fix_count;/* fixation counter */
     DbTableList all;
+    DbTableList owned;
 #ifdef ERTS_SMP
     erts_smp_rwmtx_t rwlock;  /* rw lock on table */
-    erts_smp_mtx_t fixlock;   /* Protects fixations,megasec,sec,microsec */
+    erts_smp_mtx_t fixlock;   /* Protects fixing_procs and time */
     int is_thread_safe;       /* No fine locking inside table needed */
     Uint32 type;              /* table type, *read only* after creation */
 #endif
@@ -237,7 +249,7 @@ typedef struct db_table_common {
 	ErtsMonotonicTime monotonic;
 	ErtsMonotonicTime offset;
     } time;
-    DbFixation* fixations;    /* List of processes who have done safe_fixtable,
+    DbFixation* fixing_procs; /* Tree of processes who have done safe_fixtable,
                                  "local" fixations not included. */ 
     /* All 32-bit fields */
     Uint32 status;            /* bit masks defined  below */
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index 6ff9aea5ab..7f7c06da8e 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -100,12 +100,12 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"dist_entry_links",			"address"		},
     {   "code_write_permission",                NULL                    },
     {	"purge_state",		      		NULL			},
-    {	"proc_status",				"pid"			},
-    {	"proc_trace",				"pid"			},
-    {   "ports_snapshot",                       NULL                    },
     {	"meta_name_tab",	         	"address"		},
     {	"meta_main_tab_slot",			"address"		},
     {	"db_tab",				"address"		},
+    {	"proc_status",				"pid"			},
+    {	"proc_trace",				"pid"			},
+    {   "ports_snapshot",                       NULL                    },
     {	"db_tab_fix",				"address"		},
     {	"meta_main_tab_main",			NULL 			},
     {	"db_hash_slot",				"address"		},
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index b816ba59fb..88fae30845 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -449,7 +449,8 @@ typedef enum {
     ERTS_PSTT_CPC,	/* Check Process Code */
     ERTS_PSTT_CLA,	/* Copy Literal Area */
     ERTS_PSTT_COHMQ,    /* Change off heap message queue */
-    ERTS_PSTT_FTMQ      /* Flush trace msg queue */
+    ERTS_PSTT_FTMQ,     /* Flush trace msg queue */
+    ERTS_PSTT_ETS_FREE_FIXATION
 } ErtsProcSysTaskType;
 
 #define ERTS_MAX_PROC_SYS_TASK_ARGS 2
@@ -729,6 +730,16 @@ erts_pre_init_process(void)
 	= ERTS_PSD_NIF_TRAP_EXPORT_GET_LOCKS;
     erts_psd_required_locks[ERTS_PSD_NIF_TRAP_EXPORT].set_locks
 	= ERTS_PSD_NIF_TRAP_EXPORT_SET_LOCKS;
+
+    erts_psd_required_locks[ERTS_PSD_ETS_OWNED_TABLES].get_locks
+        = ERTS_PSD_ETS_OWNED_TABLES_GET_LOCKS;
+    erts_psd_required_locks[ERTS_PSD_ETS_OWNED_TABLES].set_locks
+        = ERTS_PSD_ETS_OWNED_TABLES_SET_LOCKS;
+
+    erts_psd_required_locks[ERTS_PSD_ETS_FIXED_TABLES].get_locks
+        = ERTS_PSD_ETS_FIXED_TABLES_GET_LOCKS;
+    erts_psd_required_locks[ERTS_PSD_ETS_FIXED_TABLES].set_locks
+        = ERTS_PSD_ETS_FIXED_TABLES_SET_LOCKS;
 #endif
 }
 
@@ -11198,6 +11209,12 @@ execute_sys_tasks(Process *c_p, erts_aint32_t *statep, int in_reds)
 	    st_res = am_true;
 	    break;
 #endif
+#ifdef ERTS_SMP
+        case ERTS_PSTT_ETS_FREE_FIXATION:
+	    reds -= erts_db_execute_free_fixation(c_p, (DbFixation*)st->arg[0]);
+	    st_res = am_true;
+	    break;
+#endif
 	default:
 	    ERTS_INTERNAL_ERROR("Invalid process sys task type");
 	    st_res = am_false;
@@ -11249,7 +11266,8 @@ cleanup_sys_tasks(Process *c_p, erts_aint32_t in_state, int in_reds)
         case ERTS_PSTT_GC_MAJOR:
         case ERTS_PSTT_GC_MINOR:
 	case ERTS_PSTT_CPC:
-	case ERTS_PSTT_COHMQ:
+        case ERTS_PSTT_COHMQ:
+        case ERTS_PSTT_ETS_FREE_FIXATION:
 	    st_res = am_false;
 	    break;
 	case ERTS_PSTT_CLA:
@@ -11603,13 +11621,12 @@ erts_internal_request_system_task_4(BIF_ALIST_4)
 }
 
 static void
-erts_schedule_generic_sys_task(Eterm pid, ErtsProcSysTaskType type)
+erts_schedule_generic_sys_task(Eterm pid, ErtsProcSysTaskType type, void* arg)
 {
     Process *rp = erts_proc_lookup(pid);
     if (rp) {
 	ErtsProcSysTask *st;
 	erts_aint32_t state, fail_state;
-	int i;
 
 	st = erts_alloc(ERTS_ALC_T_PROC_SYS_TSK,
 			ERTS_PROC_SYS_TASK_SIZE(0));
@@ -11618,8 +11635,7 @@ erts_schedule_generic_sys_task(Eterm pid, ErtsProcSysTaskType type)
 	st->reply_tag = NIL;
 	st->req_id = NIL;
 	st->req_id_sz = 0;
-	for (i = 0; i < ERTS_MAX_PROC_SYS_TASK_ARGS; i++)
-	    st->arg[i] = NIL;
+        st->arg[0] = (Eterm)arg;
 	ERTS_INIT_OFF_HEAP(&st->off_heap);
 	state = erts_smp_atomic32_read_nob(&rp->state);
 
@@ -11635,7 +11651,13 @@ erts_schedule_generic_sys_task(Eterm pid, ErtsProcSysTaskType type)
 void
 erts_schedule_complete_off_heap_message_queue_change(Eterm pid)
 {
-    erts_schedule_generic_sys_task(pid, ERTS_PSTT_COHMQ);
+    erts_schedule_generic_sys_task(pid, ERTS_PSTT_COHMQ, NULL);
+}
+
+void
+erts_schedule_ets_free_fixation(Eterm pid, DbFixation* fix)
+{
+    erts_schedule_generic_sys_task(pid, ERTS_PSTT_ETS_FREE_FIXATION, fix);
 }
 
 #ifdef ERTS_DIRTY_SCHEDULERS
@@ -11683,7 +11705,7 @@ erts_schedule_flush_trace_messages(Process *proc, int force_on_proc)
     dhndl = erts_thr_progress_unmanaged_delay();
 #endif
 
-    erts_schedule_generic_sys_task(pid, ERTS_PSTT_FTMQ);
+    erts_schedule_generic_sys_task(pid, ERTS_PSTT_FTMQ, NULL);
 
 #ifdef ERTS_SMP
     erts_thr_progress_unmanaged_continue(dhndl);
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 58f1e15c23..f20dc68799 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -836,14 +836,16 @@ erts_smp_reset_max_len(ErtsRunQueue *rq, ErtsRunQueueInfo *rqi)
 #define ERTS_PSD_CALL_TIME_BP			3
 #define ERTS_PSD_DELAYED_GC_TASK_QS		4
 #define ERTS_PSD_NIF_TRAP_EXPORT		5
-#define ERTS_PSD_SUSPENDED_SAVED_CALLS_BUF	6
+#define ERTS_PSD_ETS_OWNED_TABLES               6
+#define ERTS_PSD_ETS_FIXED_TABLES               7
+#define ERTS_PSD_SUSPENDED_SAVED_CALLS_BUF	8
 
-#define ERTS_PSD_SIZE				7
+#define ERTS_PSD_SIZE				9
 
 #if !defined(HIPE)
 #  undef ERTS_PSD_SUSPENDED_SAVED_CALLS_BUF
 #  undef ERTS_PSD_SIZE
-#  define ERTS_PSD_SIZE 6
+#  define ERTS_PSD_SIZE 8
 #endif
 
 typedef struct {
@@ -871,6 +873,12 @@ typedef struct {
 #define ERTS_PSD_NIF_TRAP_EXPORT_GET_LOCKS ERTS_PROC_LOCK_MAIN
 #define ERTS_PSD_NIF_TRAP_EXPORT_SET_LOCKS ERTS_PROC_LOCK_MAIN
 
+#define ERTS_PSD_ETS_OWNED_TABLES_GET_LOCKS ERTS_PROC_LOCK_STATUS
+#define ERTS_PSD_ETS_OWNED_TABLES_SET_LOCKS ERTS_PROC_LOCK_STATUS
+
+#define ERTS_PSD_ETS_FIXED_TABLES_GET_LOCKS ERTS_PROC_LOCK_MAIN
+#define ERTS_PSD_ETS_FIXED_TABLES_SET_LOCKS ERTS_PROC_LOCK_MAIN
+
 typedef struct {
     ErtsProcLocks get_locks;
     ErtsProcLocks set_locks;
@@ -1805,6 +1813,8 @@ void erts_schedule_thr_prgr_later_cleanup_op(void (*)(void *),
 					     ErtsThrPrgrLaterOp *,
 					     UWord);
 void erts_schedule_complete_off_heap_message_queue_change(Eterm pid);
+struct db_fixation;
+void erts_schedule_ets_free_fixation(Eterm pid, struct db_fixation*);
 void erts_schedule_flush_trace_messages(Process *proc, int force_on_proc);
 int erts_flush_trace_messages(Process *c_p, ErtsProcLocks locks);
 
diff --git a/erts/emulator/beam/erl_rbtree.h b/erts/emulator/beam/erl_rbtree.h
index ebde5caca4..6a42853957 100644
--- a/erts/emulator/beam/erl_rbtree.h
+++ b/erts/emulator/beam/erl_rbtree.h
@@ -486,12 +486,12 @@ typedef struct {
 #if defined(ERTS_RBT_HARD_DEBUG) \
     && (defined(ERTS_RBT_WANT_DELETE) \
 	|| defined(ERTS_RBT_NEED_INSERT__))
-static void ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root);
+static void ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root, ERTS_RBT_T *node);
 #  define ERTS_RBT_NEED_HDBG_CHECK_TREE__
-#  define ERTS_RBT_HDBG_CHECK_TREE__(R) \
-    ERTS_RBT_FUNC__(hdbg_check_tree)((R))
+#  define ERTS_RBT_HDBG_CHECK_TREE__(R,N) \
+    ERTS_RBT_FUNC__(hdbg_check_tree)((R),(N))
 #else
-#  define ERTS_RBT_HDBG_CHECK_TREE__(R) ((void) 1)
+#  define ERTS_RBT_HDBG_CHECK_TREE__(R,N) ((void) 1)
 #endif
 
 #ifdef ERTS_RBT_NEED_ROTATE__
@@ -644,7 +644,7 @@ ERTS_RBT_FUNC__(delete)(ERTS_RBT_T **root, ERTS_RBT_T *n)
     ERTS_RBT_T null_x; /* null_x is used to get the fixup started when we
 			  splice out a node without children. */
 
-    ERTS_RBT_HDBG_CHECK_TREE__(*root);
+    ERTS_RBT_HDBG_CHECK_TREE__(*root, n);
 
     ERTS_RBT_INIT_EMPTY_TNODE(&null_x);
 
@@ -862,7 +862,7 @@ ERTS_RBT_FUNC__(delete)(ERTS_RBT_T **root, ERTS_RBT_T *n)
 	}
     }
 
-    ERTS_RBT_HDBG_CHECK_TREE__(*root);
+    ERTS_RBT_HDBG_CHECK_TREE__(*root, NULL);
 
 }
 
@@ -992,7 +992,7 @@ ERTS_RBT_FUNC__(insert_aux__)(ERTS_RBT_T **root, ERTS_RBT_T *n, int lookup)
 {
     ERTS_RBT_KEY_T kn = ERTS_RBT_GET_KEY(n);
 
-    ERTS_RBT_HDBG_CHECK_TREE__(*root);
+    ERTS_RBT_HDBG_CHECK_TREE__(*root, NULL);
 
     ERTS_RBT_INIT_EMPTY_TNODE(n);	
 
@@ -1014,7 +1014,7 @@ ERTS_RBT_FUNC__(insert_aux__)(ERTS_RBT_T **root, ERTS_RBT_T *n, int lookup)
 
 	    if (lookup && ERTS_RBT_IS_EQ(kn, kx)) {
 
-		ERTS_RBT_HDBG_CHECK_TREE__(*root);
+		ERTS_RBT_HDBG_CHECK_TREE__(*root, NULL);
 
 		return x;
 	    }
@@ -1048,7 +1048,7 @@ ERTS_RBT_FUNC__(insert_aux__)(ERTS_RBT_T **root, ERTS_RBT_T *n, int lookup)
 	    ERTS_RBT_FUNC__(insert_fixup__)(root, n);
     }
 
-    ERTS_RBT_HDBG_CHECK_TREE__(*root);
+    ERTS_RBT_HDBG_CHECK_TREE__(*root, n);
 
     return NULL;
 }
@@ -1589,15 +1589,17 @@ ERTS_RBT_FUNC__(debug_print)(FILE *filep, ERTS_RBT_T *x, int indent,
 #ifdef ERTS_RBT_NEED_HDBG_CHECK_TREE__
 
 static void
-ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root)
+ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root, ERTS_RBT_T *n)
 {
     int black_depth = -1, no_black = 0;
     ERTS_RBT_T *c, *p, *x = root;
     ERTS_RBT_KEY_T kx;
     ERTS_RBT_KEY_T kc;
 
-    if (!x)
+    if (!x) {
+        ERTS_RBT_ASSERT(!n);
 	return;
+    }
 
     ERTS_RBT_ASSERT(!ERTS_RBT_GET_PARENT(x));
 
@@ -1607,6 +1609,9 @@ ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root)
 
 	    while (1) {
 
+                if (x == n)
+                    n = NULL;
+
 		if (ERTS_RBT_IS_BLACK(x))
 		    no_black++;
 		else {
@@ -1678,6 +1683,7 @@ ERTS_RBT_FUNC__(hdbg_check_tree)(ERTS_RBT_T *root)
 	    if (!p) {
 		ERTS_RBT_ASSERT(root == x);
 		ERTS_RBT_ASSERT(no_black == 0);
+                ERTS_RBT_ASSERT(!n);
 		return; /* Done */
 	    }