Merge branch 'lukas/erts/crashdump_improvements/OTP-12377'

* lukas/erts/crashdump_improvements/OTP-12377:
  erts: Make main thread safe from pipe closed event
  erts: Improve crash dumps
  erts: Rename sys_sigset to sys_signal
  erts: Introduce thread suspend functions
  erts: Remove usage of QUANTIFY signal
  erts: Add support for thread names
  ets: Increase data available in crash dumps and ets:info
  erts: Start compilation of beam_emu earlier

23 files changed, 836 insertions, 227 deletions

diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index 53fc7bd713..e4cd566285 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -934,7 +934,7 @@ ifdef HIPE_ENABLED
 EXTRA_BASE_OBJS += $(HIPE_OBJS)
 endif
 
-BASE_OBJS = $(RUN_OBJS) $(EMU_OBJS) $(OS_OBJS) $(EXTRA_BASE_OBJS)
+BASE_OBJS = $(EMU_OBJS) $(RUN_OBJS) $(OS_OBJS) $(EXTRA_BASE_OBJS)
 
 before_DTrace_OBJS =	$(BASE_OBJS) $(DRV_OBJS)
 
diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c
index 5aee85174f..41765dad12 100644
--- a/erts/emulator/beam/break.c
+++ b/erts/emulator/beam/break.c
@@ -210,25 +210,12 @@ print_process_info(int to, void *to_arg, Process *p)
     erts_print(to, to_arg, "State: ");
 
     state = erts_smp_atomic32_read_acqb(&p->state);
-    if (state & ERTS_PSFLG_FREE)
-	erts_print(to, to_arg, "Non Existing\n"); /* Should never happen */
-    else if (state & ERTS_PSFLG_EXITING)
-	erts_print(to, to_arg, "Exiting\n");
-    else if (state & ERTS_PSFLG_GC) {
-	garbing = 1;
-	running = 1;
-	erts_print(to, to_arg, "Garbing\n");
-    }
-    else if (state & ERTS_PSFLG_SUSPENDED)
-	erts_print(to, to_arg, "Suspended\n");
-    else if (state & ERTS_PSFLG_RUNNING) {
-	running = 1;
-	erts_print(to, to_arg, "Running\n");
-    }
-    else if (state & ERTS_PSFLG_ACTIVE)
-	erts_print(to, to_arg, "Scheduled\n");
-    else
-	erts_print(to, to_arg, "Waiting\n");
+    erts_dump_process_state(to, to_arg, state);
+    if (state & ERTS_PSFLG_GC) {
+        garbing = 1;
+        running = 1;
+    } else if (state & ERTS_PSFLG_RUNNING)
+        running = 1;
 
     /*
      * If the process is registered as a global process, display the
@@ -352,6 +339,10 @@ print_process_info(int to, void *to_arg, Process *p)
 #endif
 	    erts_stack_dump(to, to_arg, p);
     }
+
+    /* Display all states */
+    erts_print(to, to_arg, "Internal State: ");
+    erts_dump_extended_process_state(to, to_arg, state);
 }
 
 static void
@@ -671,6 +662,7 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args)
 {
 #ifdef ERTS_SMP
     ErtsThrPrgrData tpd_buf; /* in case we aren't a managed thread... */
+    int bc;
 #endif
     int fd;
     size_t envsz;
@@ -681,27 +673,39 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args)
     char* dumpname;
     int secs;
     int env_erl_crash_dump_seconds_set = 1;
+    int i;
 
     if (ERTS_SOMEONE_IS_CRASH_DUMPING)
 	return;
 
 #ifdef ERTS_SMP
+    /* Order all managed threads to block, this has to be done
+       first to guarantee that this is the only thread to generate
+       crash dump. */
+    bc = erts_thr_progress_fatal_error_block(&tpd_buf);
+
+#ifdef ERTS_THR_HAVE_SIG_FUNCS
     /*
-     * Wait for all managed threads to block. If all threads haven't blocked
-     * after a minute, we go anyway and hope for the best...
-     *
-     * We do not release system again. We expect an exit() or abort() after
-     * dump has been written.
+     * We suspend all scheduler threads so that we can dump some
+     * data about the currently running processes and scheduler data.
+     * We have to be very very careful when doing this as the schedulers
+     * could be anywhere.
      */
-    erts_thr_progress_fatal_error_block(60000, &tpd_buf);
-    /* Either worked or not... */
+    for (i = 0; i < erts_no_schedulers; i++) {
+        erts_tid_t tid = ERTS_SCHEDULER_IX(i)->tid;
+        if (!erts_equal_tids(tid,erts_thr_self()))
+            sys_thr_suspend(tid);
+    }
+
+#endif
 
     /* Allow us to pass certain places without locking... */
     erts_smp_atomic32_set_mb(&erts_writing_erl_crash_dump, 1);
     erts_smp_tsd_set(erts_is_crash_dumping_key, (void *) 1);
-#else
+
+#else /* !ERTS_SMP */
     erts_writing_erl_crash_dump = 1;
-#endif
+#endif /* ERTS_SMP */
 
     envsz = sizeof(env);
     /* ERL_CRASH_DUMP_SECONDS not set
@@ -758,9 +762,8 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args)
     erts_fprintf(stderr,"\nCrash dump is being written to: %s...", dumpname);
 
     fd = open(dumpname,O_WRONLY | O_CREAT | O_TRUNC,0640);
-    if (fd < 0) 
+    if (fd < 0)
 	return; /* Can't create the crash dump, skip it */
-    
     time(&now);
     erts_fdprintf(fd, "=erl_crash_dump:0.3\n%s", ctime(&now));
 
@@ -774,9 +777,74 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args)
     erts_fdprintf(fd, "System version: ");
     erts_print_system_version(fd, NULL, NULL);
     erts_fdprintf(fd, "%s\n", "Compiled: " ERLANG_COMPILE_DATE);
+
     erts_fdprintf(fd, "Taints: ");
     erts_print_nif_taints(fd, NULL);
     erts_fdprintf(fd, "Atoms: %d\n", atom_table_size());
+
+#ifdef USE_THREADS
+    /* We want to note which thread it was that called erl_exit */
+    if (erts_get_scheduler_data()) {
+        erts_fdprintf(fd, "Calling Thread: scheduler:%d\n",
+                      erts_get_scheduler_data()->no);
+    } else {
+        if (!erts_thr_getname(erts_thr_self(), dumpnamebuf, MAXPATHLEN))
+            erts_fdprintf(fd, "Calling Thread: %s\n", dumpnamebuf);
+        else
+            erts_fdprintf(fd, "Calling Thread: %p\n", erts_thr_self());
+    }
+#else
+    erts_fdprintf(fd, "Calling Thread: scheduler:1\n");
+#endif
+
+#if defined(ERTS_HAVE_TRY_CATCH)
+
+    /*
+     * erts_print_scheduler_info is not guaranteed to be safe to call
+     * here for all schedulers as we may have suspended a scheduler
+     * in the middle of updating the STACK_TOP and STACK_START
+     * variables and thus when scanning the stack we could get
+     * segmentation faults. We protect against this very unlikely
+     * scenario by using the ERTS_SYS_TRY_CATCH.
+     */
+    for (i = 0; i < erts_no_schedulers; i++) {
+        ERTS_SYS_TRY_CATCH(
+            erts_print_scheduler_info(fd, NULL, ERTS_SCHEDULER_IX(i)),
+            erts_fdprintf(fd, "** crashed **\n"));
+    }
+#endif
+
+#ifdef ERTS_SMP
+
+#if defined(ERTS_THR_HAVE_SIG_FUNCS)
+
+    /* We resume all schedulers so that we are in a known safe state
+       when we write the rest of the crash dump */
+    for (i = 0; i < erts_no_schedulers; i++) {
+        erts_tid_t tid = ERTS_SCHEDULER_IX(i)->tid;
+        if (!erts_equal_tids(tid,erts_thr_self()))
+	    sys_thr_resume(tid);
+    }
+#endif
+
+    /*
+     * Wait for all managed threads to block. If all threads haven't blocked
+     * after a minute, we go anyway and hope for the best...
+     *
+     * We do not release system again. We expect an exit() or abort() after
+     * dump has been written.
+     */
+    erts_thr_progress_fatal_error_wait(60000);
+    /* Either worked or not... */
+#endif
+
+#ifndef ERTS_HAVE_TRY_CATCH
+    /* This is safe to call here, as all schedulers are blocked */
+    for (i = 0; i < erts_no_schedulers; i++) {
+        erts_print_scheduler_info(fd, NULL, ERTS_SCHEDULER_IX(i));
+    }
+#endif
+    
     info(fd, NULL); /* General system info */
     if (erts_ptab_initialized(&erts_proc))
 	process_info(fd, NULL); /* Info about each process and port */
diff --git a/erts/emulator/beam/erl_async.c b/erts/emulator/beam/erl_async.c
index decae6b2ca..bc06d41720 100644
--- a/erts/emulator/beam/erl_async.c
+++ b/erts/emulator/beam/erl_async.c
@@ -176,7 +176,7 @@ erts_init_async(void)
 	ErtsThrQInit_t qinit = ERTS_THR_Q_INIT_DEFAULT;
 #endif
 	erts_thr_opts_t thr_opts = ERTS_THR_OPTS_DEFAULT_INITER;
-	char *ptr;
+	char *ptr, thr_name[16];
 	size_t tot_size = 0;
 	int i;
 
@@ -227,23 +227,16 @@ erts_init_async(void)
 	thr_opts.suggested_stack_size
 	    = erts_async_thread_suggested_stack_size;
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-	thr_opts.name = malloc(sizeof(char)*(strlen("async_XXXX")+1));
-#endif
+	thr_opts.name = thr_name;
 
 	for (i = 0; i < erts_async_max_threads; i++) {
 	    ErtsAsyncQ *aq = async_q(i);
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-            sprintf(thr_opts.name, "async_%d", i+1);
-#endif
+            erts_snprintf(thr_opts.name, 16, "async_%d", i+1);
 
 	    erts_thr_create(&aq->thr_id, async_main, (void*) aq, &thr_opts);
 	}
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-	free(thr_opts.name);
-#endif
 	/* Wait for async threads to initialize... */
 
 	erts_mtx_lock(&async->init.data.mtx);
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index d2ee5e4224..d750e34be3 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -3900,6 +3900,13 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 		}
 	    }
 	}
+        else if (ERTS_IS_ATOM_STR("broken_halt", BIF_ARG_1)) {
+            /* Ugly ugly code used by bif_SUITE:erlang_halt/1 */
+#if defined(ERTS_HAVE_TRY_CATCH)
+	    erts_get_scheduler_data()->run_queue = NULL;
+#endif
+            erl_exit(ERTS_DUMP_EXIT, "%T", BIF_ARG_2);
+        }
     }
 
     BIF_ERROR(BIF_P, BADARG);
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index fba1e32230..4806befd99 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -2668,7 +2668,9 @@ BIF_RETTYPE ets_match_object_3(BIF_ALIST_3)
 BIF_RETTYPE ets_info_1(BIF_ALIST_1)
 {
     static Eterm fields[] = {am_protection, am_keypos, am_type, am_named_table,
-	am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed};
+                             am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed,
+                             am_write_concurrency,
+                             am_read_concurrency};
     Eterm results[sizeof(fields)/sizeof(Eterm)];
     DbTable* tb;
     Eterm res;
@@ -3695,6 +3697,10 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 	    ret = am_protected;
 	else if (tb->common.status & DB_PUBLIC)
 	    ret = am_public;
+    } else if (What == am_write_concurrency) {
+        ret = tb->common.status & DB_FINE_LOCKED ? am_true : am_false;
+    } else if (What == am_read_concurrency) {
+        ret = tb->common.status & DB_FREQ_READ ? am_true : am_false;
     } else if (What == am_name) {
 	ret = tb->common.the_name;
     } else if (What == am_keypos) {
@@ -3777,7 +3783,7 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 			 avg, std_dev_real, std_dev_exp,
 			 make_small(stats.min_chain_len),
 			 make_small(stats.max_chain_len),
-			 make_small(db_kept_items_hash(&tb->hash)));
+			 make_small(stats.kept_items));
 	}
 	else {
 	    ret = am_false;
@@ -3799,6 +3805,11 @@ static void print_table(int to, void *to_arg, int show,  DbTable* tb)
 			+ sizeof(Uint)
 			- 1)
 		       / sizeof(Uint)));
+    erts_print(to, to_arg, "Type: %T\n", table_info(NULL, tb, am_type));
+    erts_print(to, to_arg, "Protection: %T\n", table_info(NULL, tb, am_protection));
+    erts_print(to, to_arg, "Compressed: %T\n", table_info(NULL, tb, am_compressed));
+    erts_print(to, to_arg, "Write Concurrency: %T\n", table_info(NULL, tb, am_write_concurrency));
+    erts_print(to, to_arg, "Read Concurrency: %T\n", table_info(NULL, tb, am_read_concurrency));
 }
 
 void db_info(int to, void *to_arg, int show)    /* Called by break handler */
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 6e8d892561..c2157457a0 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -648,25 +648,6 @@ restart:
     /* ToDo: Maybe try grow/shrink the table as well */
 }
 
-/* Only used by tests
-*/
-Uint db_kept_items_hash(DbTableHash *tb)
-{
-    Uint kept_items = 0;
-    Uint ix = 0;
-    erts_smp_rwmtx_t* lck = RLOCK_HASH(tb,ix);
-    HashDbTerm* b;
-    do {
-	for (b = BUCKET(tb, ix); b != NULL; b = b->next) {
-	    if (b->hvalue == INVALID_HASH) {
-		++kept_items;
-	    }
-	}	
-	ix = next_slot(tb, ix, &lck);
-    }while (ix);
-    return kept_items;
-}
-
 int db_create_hash(Process *p, DbTable *tbl)
 {
     DbTableHash *tb = &tbl->hash;
@@ -2161,10 +2142,38 @@ int db_mark_all_deleted_hash(DbTable *tbl)
 static void db_print_hash(int to, void *to_arg, int show, DbTable *tbl)
 {
     DbTableHash *tb = &tbl->hash;
+    DbHashStats stats;
     int i;
 
     erts_print(to, to_arg, "Buckets: %d\n", NACTIVE(tb));
-    
+
+#ifdef ERTS_SMP
+    i = tbl->common.is_thread_safe;
+    /* If crash dumping we set table to thread safe in order to
+       avoid taking any locks */
+    if (ERTS_IS_CRASH_DUMPING)
+        tbl->common.is_thread_safe = 1;
+
+    db_calc_stats_hash(&tbl->hash, &stats);
+
+    tbl->common.is_thread_safe = i;
+#else
+    db_calc_stats_hash(&tbl->hash, &stats);
+#endif
+
+    erts_print(to, to_arg, "Chain Length Avg: %f\n", stats.avg_chain_len);
+    erts_print(to, to_arg, "Chain Length Max: %d\n", stats.max_chain_len);
+    erts_print(to, to_arg, "Chain Length Min: %d\n", stats.min_chain_len);
+    erts_print(to, to_arg, "Chain Length Std Dev: %f\n",
+               stats.std_dev_chain_len);
+    erts_print(to, to_arg, "Chain Length Expected Std Dev: %f\n",
+               stats.std_dev_expected);
+
+    if (IS_FIXED(tb))
+        erts_print(to, to_arg, "Fixed: %d\n", stats.kept_items);
+    else
+        erts_print(to, to_arg, "Fixed: false\n");
+
     if (show) {
 	for (i = 0; i < NACTIVE(tb); i++) {
 	    HashDbTerm* list = BUCKET(tb,i);
@@ -2890,6 +2899,7 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
     erts_smp_rwmtx_t* lck;
     int sum = 0;
     int sq_sum = 0;
+    int kept_items = 0;
     int ix;
     int len;
     
@@ -2901,6 +2911,8 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
 	len = 0;
 	for (b = BUCKET(tb,ix); b!=NULL; b=b->next) {
 	    len++;
+            if (b->hvalue == INVALID_HASH)
+                ++kept_items;
 	}
 	sum += len;
 	sq_sum += len*len;
@@ -2912,7 +2924,8 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
     stats->std_dev_chain_len = sqrt((sq_sum - stats->avg_chain_len*sum) / NACTIVE(tb));
     /* Expected	standard deviation from a good uniform hash function, 
        ie binomial distribution (not taking the linear hashing into acount) */
-    stats->std_dev_expected = sqrt(stats->avg_chain_len * (1 - 1.0/NACTIVE(tb)));	
+    stats->std_dev_expected = sqrt(stats->avg_chain_len * (1 - 1.0/NACTIVE(tb)));
+    stats->kept_items = kept_items;
 }
 #ifdef HARDDEBUG
 
diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h
index e68081a5b1..f12cd363b0 100644
--- a/erts/emulator/beam/erl_db_hash.h
+++ b/erts/emulator/beam/erl_db_hash.h
@@ -104,6 +104,7 @@ typedef struct {
     float std_dev_expected;
     int max_chain_len;
     int min_chain_len;
+    int kept_items;
 }DbHashStats;
 
 void db_calc_stats_hash(DbTableHash* tb, DbHashStats*);
diff --git a/erts/emulator/beam/erl_drv_thread.c b/erts/emulator/beam/erl_drv_thread.c
index 147249f751..31b05d22af 100644
--- a/erts/emulator/beam/erl_drv_thread.c
+++ b/erts/emulator/beam/erl_drv_thread.c
@@ -601,17 +601,14 @@ erl_drv_thread_create(char *name,
 #ifdef USE_THREADS
     int res;
     struct ErlDrvTid_ *dtid;
-    ethr_thr_opts ethr_opts;
+    ethr_thr_opts ethr_opts = ETHR_THR_OPTS_DEFAULT_INITER;
     ethr_thr_opts *use_opts;
-    ethr_thr_opts def_ethr_opts = ETHR_THR_OPTS_DEFAULT_INITER;
 
     if (!opts)
 	use_opts = NULL;
     else {
-	sys_memcpy((void *) &ethr_opts,
-		   (void *) &def_ethr_opts,
-		   sizeof(ethr_thr_opts));
 	ethr_opts.suggested_stack_size = opts->suggested_stack_size;
+        ethr_opts.name = name;
 	use_opts = &ethr_opts;
     }
 
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 07daabefc7..ba09ee57c2 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -457,8 +457,7 @@ do {									\
 
 static void exec_misc_ops(ErtsRunQueue *);
 static void print_function_from_pc(int to, void *to_arg, BeamInstr* x);
-static int stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp,
-			      int yreg);
+static int stack_element_dump(int to, void *to_arg, Eterm* sp, int yreg);
 
 static void aux_work_timeout(void *unused);
 static void aux_work_timeout_early_init(int no_schedulers);
@@ -7834,23 +7833,17 @@ erts_start_schedulers(void)
     Uint actual;
     Uint wanted = erts_no_schedulers;
     Uint wanted_no_schedulers = erts_no_schedulers;
+    char name[16];
     ethr_thr_opts opts = ETHR_THR_OPTS_DEFAULT_INITER;
 
     opts.detached = 1;
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-    opts.name = malloc(80);
-    if (!opts.name) {
-        ERTS_INTERNAL_ERROR("malloc failed to allocate memory!");
-    }
-#endif
+    opts.name = name;
 
 #ifdef ERTS_SMP
     if (erts_runq_supervision_interval) {
 	opts.suggested_stack_size = 16;
-#ifdef ETHR_HAVE_THREAD_NAMES
-        sprintf(opts.name, "runq_supervisor");
-#endif
+        erts_snprintf(opts.name, 16, "runq_supervisor");
 	erts_atomic_init_nob(&runq_supervisor_sleeping, 0);
 	if (0 != ethr_event_init(&runq_supervision_event))
 	    erl_exit(1, "Failed to create run-queue supervision event\n");
@@ -7877,9 +7870,7 @@ erts_start_schedulers(void)
 
 	ASSERT(actual == esdp->no - 1);
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-	sprintf(opts.name, "scheduler_%d", actual + 1);
-#endif
+	erts_snprintf(opts.name, 16, "%lu_scheduler", actual + 1);
 
 #ifdef __OSE__
         /* This should be done in the bind strategy */
@@ -7901,18 +7892,14 @@ erts_start_schedulers(void)
 	int ix;
 	for (ix = 0; ix < erts_no_dirty_cpu_schedulers; ix++) {
 	    ErtsSchedulerData *esdp = ERTS_DIRTY_CPU_SCHEDULER_IX(ix);
-#ifdef ETHR_HAVE_THREAD_NAMES
-            sprintf(opts.name,"dirty_cpu_scheduler_%d", ix + 1);
-#endif
+	    erts_snprintf(opts.name, 16, "%d_dirty_cpu_scheduler", ix + 1);
 	    res = ethr_thr_create(&esdp->tid,sched_dirty_cpu_thread_func,(void*)esdp,&opts);
 	    if (res != 0)
 		erl_exit(1, "Failed to create dirty cpu scheduler thread %d\n", ix);
 	}
 	for (ix = 0; ix < erts_no_dirty_io_schedulers; ix++) {
 	    ErtsSchedulerData *esdp = ERTS_DIRTY_IO_SCHEDULER_IX(ix);
-#ifdef ETHR_HAVE_THREAD_NAMES
-            sprintf(opts.name,"dirty_io_scheduler_%d", ix + 1);
-#endif
+	    erts_snprintf(opts.name, 16, "%d_dirty_io_scheduler", ix + 1);
 	    res = ethr_thr_create(&esdp->tid,sched_dirty_io_thread_func,(void*)esdp,&opts);
 	    if (res != 0)
 		erl_exit(1, "Failed to create dirty io scheduler thread %d\n", ix);
@@ -7923,9 +7910,7 @@ erts_start_schedulers(void)
 
     ERTS_THR_MEMORY_BARRIER;
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-    sprintf(opts.name, "aux");
-#endif
+    erts_snprintf(opts.name, 16, "aux");
 
 #ifdef __OSE__
     opts.coreNo = 0;
@@ -7951,9 +7936,6 @@ erts_start_schedulers(void)
 	erts_send_error_to_logger_nogl(dsbufp);
     }
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-    free(opts.name);
-#endif
 }
 
 #endif /* ERTS_SMP */
@@ -12154,7 +12136,7 @@ erts_stack_dump(int to, void *to_arg, Process *p)
     }
     erts_program_counter_info(to, to_arg, p);
     for (sp = p->stop; sp < STACK_START(p); sp++) {
-        yreg = stack_element_dump(to, to_arg, p, sp, yreg);
+        yreg = stack_element_dump(to, to_arg, sp, yreg);
     }
 }
 
@@ -12211,7 +12193,7 @@ print_function_from_pc(int to, void *to_arg, BeamInstr* x)
 }
 
 static int
-stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp, int yreg)
+stack_element_dump(int to, void *to_arg, Eterm* sp, int yreg)
 {
     Eterm x = *sp;
 
@@ -12240,6 +12222,214 @@ stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp, int yreg)
 }
 
 /*
+ * Print scheduler information
+ */
+void
+erts_print_scheduler_info(int to, void *to_arg, ErtsSchedulerData *esdp) {
+    int i;
+    erts_aint32_t flg;
+    Process *p;
+
+    erts_print(to, to_arg, "=scheduler:%u\n", esdp->no);
+
+#ifdef ERTS_SMP
+    flg = erts_smp_atomic32_read_dirty(&esdp->ssi->flags);
+    erts_print(to, to_arg, "Scheduler Sleep Info Flags: ");
+    for (i = 0; i < ERTS_SSI_FLGS_MAX && flg; i++) {
+        erts_aint32_t chk = (1 << i);
+        if (flg & chk) {
+            switch (chk) {
+            case ERTS_SSI_FLG_SLEEPING:
+                erts_print(to, to_arg, "SLEEPING"); break;
+            case ERTS_SSI_FLG_POLL_SLEEPING:
+                erts_print(to, to_arg, "POLL_SLEEPING"); break;
+            case ERTS_SSI_FLG_TSE_SLEEPING:
+                erts_print(to, to_arg, "TSE_SLEEPING"); break;
+            case ERTS_SSI_FLG_WAITING:
+                erts_print(to, to_arg, "WAITING"); break;
+            case ERTS_SSI_FLG_SUSPENDED:
+                erts_print(to, to_arg, "SUSPENDED"); break;
+            default:
+                erts_print(to, to_arg, "UNKNOWN(%d)", flg); break;
+            }
+            if (flg > chk)
+                erts_print(to, to_arg, " | ");
+            flg -= chk;
+        }
+    }
+    erts_print(to, to_arg, "\n");
+#endif
+
+    flg = erts_atomic32_read_dirty(&esdp->ssi->aux_work);
+    erts_print(to, to_arg, "Scheduler Sleep Info Aux Work: ");
+    for (i = 0; i < ERTS_SSI_AUX_WORK_MAX && flg; i++) {
+        erts_aint32_t chk = (1 << i);
+        if (flg & chk) {
+            switch (chk) {
+            case ERTS_SSI_AUX_WORK_DELAYED_AW_WAKEUP:
+                erts_print(to, to_arg, "DELAYED_AW_WAKEUP"); break;
+            case ERTS_SSI_AUX_WORK_DD:
+                erts_print(to, to_arg, "DELAYED_DEALLOC"); break;
+            case ERTS_SSI_AUX_WORK_DD_THR_PRGR:
+                erts_print(to, to_arg, "DELAYED_DEALLOC_THR_PRGR"); break;
+            case ERTS_SSI_AUX_WORK_FIX_ALLOC_DEALLOC:
+                erts_print(to, to_arg, "FIX_ALLOC_DEALLOC"); break;
+            case ERTS_SSI_AUX_WORK_FIX_ALLOC_LOWER_LIM:
+                erts_print(to, to_arg, "FIX_ALLOC_LOWER_LIM"); break;
+            case ERTS_SSI_AUX_WORK_THR_PRGR_LATER_OP:
+                erts_print(to, to_arg, "THR_PRGR_LATER_OP"); break;
+            case ERTS_SSI_AUX_WORK_ASYNC_READY:
+                erts_print(to, to_arg, "ASYNC_READY"); break;
+            case ERTS_SSI_AUX_WORK_ASYNC_READY_CLEAN:
+                erts_print(to, to_arg, "ASYNC_READY_CLEAN"); break;
+            case ERTS_SSI_AUX_WORK_MISC_THR_PRGR:
+                erts_print(to, to_arg, "MISC_THR_PRGR"); break;
+            case ERTS_SSI_AUX_WORK_MISC:
+                erts_print(to, to_arg, "MISC"); break;
+            case ERTS_SSI_AUX_WORK_CHECK_CHILDREN:
+                erts_print(to, to_arg, "CHECK_CHILDREN"); break;
+            case ERTS_SSI_AUX_WORK_SET_TMO:
+                erts_print(to, to_arg, "SET_TMO"); break;
+            case ERTS_SSI_AUX_WORK_MSEG_CACHE_CHECK:
+                erts_print(to, to_arg, "MSEG_CACHE_CHECK"); break;
+            case ERTS_SSI_AUX_WORK_REAP_PORTS:
+                erts_print(to, to_arg, "REAP_PORTS"); break;
+            default:
+                erts_print(to, to_arg, "UNKNOWN(%d)", flg); break;
+            }
+            if (flg > chk)
+                erts_print(to, to_arg, " | ");
+            flg -= chk;
+        }
+    }
+    erts_print(to, to_arg, "\n");
+
+    erts_print(to, to_arg, "Current Port: ");
+    if (esdp->current_port)
+        erts_print(to, to_arg, "%T", esdp->current_port->common.id);
+    erts_print(to, to_arg, "\n");
+
+    p = esdp->current_process;
+    erts_print(to, to_arg, "Current Process: ");
+    if (esdp->current_process && !(ERTS_TRACE_FLAGS(p) & F_SENSITIVE)) {
+      flg = erts_smp_atomic32_read_dirty(&p->state);
+      erts_print(to, to_arg, "%T\n", p->common.id);
+      
+      erts_print(to, to_arg, "Current Process State: ");
+      erts_dump_process_state(to, to_arg, flg);
+      
+      erts_print(to, to_arg, "Current Process Internal State: ");
+      erts_dump_extended_process_state(to, to_arg, flg);
+      
+      erts_print(to, to_arg, "Current Process Program counter: %p (", p->i);
+      print_function_from_pc(to, to_arg, p->i);
+      erts_print(to, to_arg, ")\n");
+      erts_print(to, to_arg, "Current Process CP: %p (", p->cp);
+      print_function_from_pc(to, to_arg, p->cp);
+      erts_print(to, to_arg, ")\n");
+      
+      /* Getting this stacktrace can segfault if we are very very
+	 unlucky if called while a process is being garbage collected.
+	 Therefore we only call this on other schedulers if we either
+	 have protection against segfaults, or we know that the process
+	 is not garbage collecting. It *should* always be safe to call
+	 on a process owned by us, even if it is currently being garbage
+	 collected.
+      */
+      erts_print(to, to_arg, "Current Process Limited Stack Trace:\n");
+      erts_limited_stack_trace(to, to_arg, p);
+    } else
+      erts_print(to, to_arg, "\n");
+
+    for (i = 0; i < ERTS_NO_PROC_PRIO_LEVELS; i++) {
+        erts_print(to, to_arg, "Run Queue ");
+        switch (i) {
+        case PRIORITY_MAX:
+            erts_print(to, to_arg, "Max ");
+            break;
+        case PRIORITY_HIGH:
+            erts_print(to, to_arg, "High ");
+            break;
+        case PRIORITY_NORMAL:
+            erts_print(to, to_arg, "Normal ");
+            break;
+        case PRIORITY_LOW:
+            erts_print(to, to_arg, "Low ");
+            break;
+        default:
+            erts_print(to, to_arg, "Unknown ");
+            break;
+        }
+        erts_print(to, to_arg, "Length: %d\n",
+                   erts_smp_atomic32_read_dirty(&esdp->run_queue->procs.prio_info[i].len));
+    }
+    erts_print(to, to_arg, "Run Queue Port Length: %d\n",
+               erts_smp_atomic32_read_dirty(&esdp->run_queue->ports.info.len));
+
+    flg = erts_smp_atomic32_read_dirty(&esdp->run_queue->flags);
+    erts_print(to, to_arg, "Run Queue Flags: ");
+    for (i = 0; i < ERTS_RUNQ_FLG_MAX && flg; i++) {
+        erts_aint32_t chk = (1 << i);
+        if (flg & chk) {
+            switch (chk) {
+            case (1 << PRIORITY_MAX):
+                erts_print(to, to_arg, "NONEMPTY_MAX"); break;
+            case (1 << PRIORITY_HIGH):
+                erts_print(to, to_arg, "NONEMPTY_HIGH"); break;
+            case (1 << PRIORITY_NORMAL):
+                erts_print(to, to_arg, "NONEMPTY_NORMAL"); break;
+            case (1 << PRIORITY_LOW):
+                erts_print(to, to_arg, "NONEMPTY_LOW"); break;
+            case (1 << (PRIORITY_MAX + ERTS_RUNQ_FLGS_EMIGRATE_SHFT)):
+                erts_print(to, to_arg, "EMIGRATE_MAX"); break;
+            case (1 << (PRIORITY_HIGH + ERTS_RUNQ_FLGS_EMIGRATE_SHFT)):
+                erts_print(to, to_arg, "EMIGRATE_HIGH"); break;
+            case (1 << (PRIORITY_NORMAL + ERTS_RUNQ_FLGS_EMIGRATE_SHFT)):
+                erts_print(to, to_arg, "EMIGRATE_NORMAL"); break;
+            case (1 << (PRIORITY_LOW + ERTS_RUNQ_FLGS_EMIGRATE_SHFT)):
+                erts_print(to, to_arg, "EMIGRATE_LOW"); break;
+            case (1 << (PRIORITY_MAX + ERTS_RUNQ_FLGS_IMMIGRATE_SHFT)):
+                erts_print(to, to_arg, "IMMIGRATE_MAX"); break;
+            case (1 << (PRIORITY_HIGH + ERTS_RUNQ_FLGS_IMMIGRATE_SHFT)):
+                erts_print(to, to_arg, "IMMIGRATE_HIGH"); break;
+            case (1 << (PRIORITY_NORMAL + ERTS_RUNQ_FLGS_IMMIGRATE_SHFT)):
+                erts_print(to, to_arg, "IMMIGRATE_NORMAL"); break;
+            case (1 << (PRIORITY_LOW + ERTS_RUNQ_FLGS_IMMIGRATE_SHFT)):
+                erts_print(to, to_arg, "IMMIGRATE_LOW"); break;
+            case (1 << (PRIORITY_MAX + ERTS_RUNQ_FLGS_EVACUATE_SHFT)):
+                erts_print(to, to_arg, "EVACUATE_MAX"); break;
+            case (1 << (PRIORITY_HIGH + ERTS_RUNQ_FLGS_EVACUATE_SHFT)):
+                erts_print(to, to_arg, "EVACUATE_HIGH"); break;
+            case (1 << (PRIORITY_NORMAL + ERTS_RUNQ_FLGS_EVACUATE_SHFT)):
+                erts_print(to, to_arg, "EVACUATE_NORMAL"); break;
+            case (1 << (PRIORITY_LOW + ERTS_RUNQ_FLGS_EVACUATE_SHFT)):
+                erts_print(to, to_arg, "EVACUATE_LOW"); break;
+            case ERTS_RUNQ_FLG_OUT_OF_WORK:
+                erts_print(to, to_arg, "OUT_OF_WORK"); break;
+            case ERTS_RUNQ_FLG_HALFTIME_OUT_OF_WORK:
+                erts_print(to, to_arg, "HALFTIME_OUT_OF_WORK"); break;
+            case ERTS_RUNQ_FLG_SUSPENDED:
+                erts_print(to, to_arg, "SUSPENDED"); break;
+            case ERTS_RUNQ_FLG_CHK_CPU_BIND:
+                erts_print(to, to_arg, "CHK_CPU_BIND"); break;
+            case ERTS_RUNQ_FLG_INACTIVE:
+                erts_print(to, to_arg, "INACTIVE"); break;
+            case ERTS_RUNQ_FLG_NONEMPTY:
+                erts_print(to, to_arg, "NONEMPTY"); break;
+            case ERTS_RUNQ_FLG_PROTECTED:
+                erts_print(to, to_arg, "PROTECTED"); break;
+            default:
+                erts_print(to, to_arg, "UNKNOWN(%d)", flg); break;
+            }
+            if (flg > chk)
+                erts_print(to, to_arg, " | ");
+            flg -= chk;
+        }
+    }
+    erts_print(to, to_arg, "\n");
+}
+
+/*
  * A nice system halt closing all open port goes as follows:
  * 1) This function schedules the aux work ERTS_SSI_AUX_WORK_REAP_PORTS
  *    on all schedulers, then schedules itself out.
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 55009ad904..d12ac792af 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -170,6 +170,8 @@ extern int erts_sched_thread_suggested_stack_size;
 #define ERTS_RUNQ_FLG_PROTECTED \
   (((Uint32) 1) << (ERTS_RUNQ_FLG_BASE2 + 6))
 
+#define ERTS_RUNQ_FLG_MAX (ERTS_RUNQ_FLG_BASE2 + 7)
+
 #define ERTS_RUNQ_FLGS_MIGRATION_QMASKS	\
   (ERTS_RUNQ_FLGS_EMIGRATE_QMASK	\
    | ERTS_RUNQ_FLGS_IMMIGRATE_QMASK	\
@@ -252,6 +254,8 @@ typedef enum {
 #define ERTS_SSI_FLG_WAITING		(((erts_aint32_t) 1) << 3)
 #define ERTS_SSI_FLG_SUSPENDED	 	(((erts_aint32_t) 1) << 4)
 
+#define ERTS_SSI_FLGS_MAX                                       5
+
 #define ERTS_SSI_FLGS_SLEEP_TYPE			\
  (ERTS_SSI_FLG_TSE_SLEEPING|ERTS_SSI_FLG_POLL_SLEEPING)
 
@@ -283,6 +287,8 @@ typedef enum {
 #define ERTS_SSI_AUX_WORK_MSEG_CACHE_CHECK	(((erts_aint32_t) 1) << 12)
 #define ERTS_SSI_AUX_WORK_REAP_PORTS		(((erts_aint32_t) 1) << 13)
 
+#define ERTS_SSI_AUX_WORK_MAX                                           14
+
 typedef struct ErtsSchedulerSleepInfo_ ErtsSchedulerSleepInfo;
 
 #ifdef ERTS_DIRTY_SCHEDULERS
@@ -1075,6 +1081,9 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(19)
 #define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(20)
 #define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(21)
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 22)
+#else
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 18)
 #endif
 
 #define ERTS_PSFLGS_IN_PRQ_MASK 	(ERTS_PSFLG_IN_PRQ_MAX		\
@@ -1610,7 +1619,11 @@ void erts_cleanup_empty_process(Process* p);
 void erts_debug_verify_clean_empty_process(Process* p);
 #endif
 void erts_stack_dump(int to, void *to_arg, Process *);
+void erts_limited_stack_trace(int to, void *to_arg, Process *);
 void erts_program_counter_info(int to, void *to_arg, Process *);
+void erts_print_scheduler_info(int to, void *to_arg, ErtsSchedulerData *esdp);
+void erts_dump_extended_process_state(int to, void *to_arg, erts_aint32_t psflg);
+void erts_dump_process_state(int to, void *to_arg, erts_aint32_t psflg);
 
 Eterm erts_get_process_priority(Process *p);
 Eterm erts_set_process_priority(Process *p, Eterm prio);
diff --git a/erts/emulator/beam/erl_process_dump.c b/erts/emulator/beam/erl_process_dump.c
index 2f3cf23b00..36bb6b2f0e 100644
--- a/erts/emulator/beam/erl_process_dump.c
+++ b/erts/emulator/beam/erl_process_dump.c
@@ -43,8 +43,9 @@ static void dump_process_info(int to, void *to_arg, Process *p);
 static void dump_element(int to, void *to_arg, Eterm x);
 static void dump_dist_ext(int to, void *to_arg, ErtsDistExternal *edep);
 static void dump_element_nl(int to, void *to_arg, Eterm x);
-static int stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp,
+static int stack_element_dump(int to, void *to_arg, Eterm* sp,
 			      int yreg);
+static void stack_trace_dump(int to, void *to_arg, Eterm* sp);
 static void print_function_from_pc(int to, void *to_arg, BeamInstr* x);
 static void heap_dump(int to, void *to_arg, Eterm x);
 static void dump_binaries(int to, void *to_arg, Binary* root);
@@ -148,7 +149,7 @@ dump_process_info(int to, void *to_arg, Process *p)
     if ((ERTS_TRACE_FLAGS(p) & F_SENSITIVE) == 0) {
 	erts_print(to, to_arg, "=proc_stack:%T\n", p->common.id);
 	for (sp = p->stop; sp < STACK_START(p); sp++) {
-	    yreg = stack_element_dump(to, to_arg, p, sp, yreg);
+	    yreg = stack_element_dump(to, to_arg, sp, yreg);
 	}
 
 	erts_print(to, to_arg, "=proc_heap:%T\n", p->common.id);
@@ -243,9 +244,65 @@ dump_element_nl(int to, void *to_arg, Eterm x)
     erts_putc(to, to_arg, '\n');
 }
 
+static void
+stack_trace_dump(int to, void *to_arg, Eterm *sp) {
+    Eterm x = *sp;
+    if (is_CP(x)) {
+        erts_print(to, to_arg, "%p:", sp);
+        erts_print(to, to_arg, "SReturn addr 0x%X (", cp_val(x));
+        print_function_from_pc(to, to_arg, cp_val(x));
+        erts_print(to, to_arg, ")\n");
+    }
+}
+
+void
+erts_limited_stack_trace(int to, void *to_arg, Process *p)
+{
+    Eterm* sp;
+
+
+    if (ERTS_TRACE_FLAGS(p) & F_SENSITIVE) {
+	return;
+    }
+
+    if (STACK_START(p) < STACK_TOP(p)) {
+        return;
+    }
+
+    if ((STACK_START(p) - STACK_TOP(p)) < 512) {
+        if (erts_sys_is_area_readable((char*)STACK_TOP(p),
+                                      (char*)STACK_START(p)))
+            for (sp = STACK_TOP(p); sp < STACK_START(p); sp++)
+                stack_trace_dump(to, to_arg, sp);
+        else
+            erts_print(to, to_arg, "Could not read from stack memory: %p - %p\n",
+                       STACK_TOP(p), STACK_START(p));
+    } else {
+        sp = STACK_TOP(p);
+        if (erts_sys_is_area_readable((char*)STACK_TOP(p),
+                                      (char*)(STACK_TOP(p) + 25)))
+            for (; sp < (STACK_TOP(p) + 256); sp++)
+                stack_trace_dump(to, to_arg, sp);
+        else
+            erts_print(to, to_arg, "Could not read from stack memory: %p - %p\n",
+                       STACK_TOP(p), STACK_TOP(p) + 256);
+
+        erts_print(to, to_arg, "%p: skipping %d frames\n",
+                   sp, STACK_START(p) - STACK_TOP(p) - 512);
+
+        if (erts_sys_is_area_readable((char*)(STACK_START(p) - 256),
+                                      (char*)STACK_START(p)))
+            for (sp = STACK_START(p) - 256; sp < STACK_START(p); sp++)
+                stack_trace_dump(to, to_arg, sp);
+        else
+            erts_print(to, to_arg, "Could not read from stack memory: %p - %p\n",
+                       STACK_START(p) - 256, STACK_START(p));
+    }
+
+}
 
 static int
-stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp, int yreg)
+stack_element_dump(int to, void *to_arg, Eterm* sp, int yreg)
 {
     Eterm x = *sp;
 
@@ -508,3 +565,114 @@ dump_externally(int to, void *to_arg, Eterm term)
 	erts_print(to, to_arg, "%02X", *s++);
     }
 }
+
+void erts_dump_process_state(int to, void *to_arg, erts_aint32_t psflg) {
+    if (psflg & ERTS_PSFLG_FREE)
+	erts_print(to, to_arg, "Non Existing\n"); /* Should never happen */
+    else if (psflg & ERTS_PSFLG_EXITING)
+	erts_print(to, to_arg, "Exiting\n");
+    else if (psflg & ERTS_PSFLG_GC) {
+	erts_print(to, to_arg, "Garbing\n");
+    }
+    else if (psflg & ERTS_PSFLG_SUSPENDED)
+	erts_print(to, to_arg, "Suspended\n");
+    else if (psflg & ERTS_PSFLG_RUNNING) {
+	erts_print(to, to_arg, "Running\n");
+    }
+    else if (psflg & ERTS_PSFLG_ACTIVE)
+	erts_print(to, to_arg, "Scheduled\n");
+    else
+	erts_print(to, to_arg, "Waiting\n");
+}
+
+void
+erts_dump_extended_process_state(int to, void *to_arg, erts_aint32_t psflg) {
+
+    int i;
+
+    switch (ERTS_PSFLGS_GET_ACT_PRIO(psflg)) {
+    case PRIORITY_MAX: erts_print(to, to_arg, "ACT_PRIO_MAX | "); break;
+    case PRIORITY_HIGH: erts_print(to, to_arg, "ACT_PRIO_HIGH | "); break;
+    case PRIORITY_NORMAL: erts_print(to, to_arg, "ACT_PRIO_NORMAL | "); break;
+    case PRIORITY_LOW: erts_print(to, to_arg, "ACT_PRIO_LOW | "); break;
+    }
+    switch (ERTS_PSFLGS_GET_USR_PRIO(psflg)) {
+    case PRIORITY_MAX: erts_print(to, to_arg, "USR_PRIO_MAX | "); break;
+    case PRIORITY_HIGH: erts_print(to, to_arg, "USR_PRIO_HIGH | "); break;
+    case PRIORITY_NORMAL: erts_print(to, to_arg, "USR_PRIO_NORMAL | "); break;
+    case PRIORITY_LOW: erts_print(to, to_arg, "USR_PRIO_LOW | "); break;
+    }
+    switch (ERTS_PSFLGS_GET_PRQ_PRIO(psflg)) {
+    case PRIORITY_MAX: erts_print(to, to_arg, "PRQ_PRIO_MAX"); break;
+    case PRIORITY_HIGH: erts_print(to, to_arg, "PRQ_PRIO_HIGH"); break;
+    case PRIORITY_NORMAL: erts_print(to, to_arg, "PRQ_PRIO_NORMAL"); break;
+    case PRIORITY_LOW: erts_print(to, to_arg, "PRQ_PRIO_LOW"); break;
+    }
+
+    psflg &= ~(ERTS_PSFLGS_ACT_PRIO_MASK |
+               ERTS_PSFLGS_USR_PRIO_MASK |
+               ERTS_PSFLGS_PRQ_PRIO_MASK);
+
+    if (psflg)
+        erts_print(to, to_arg, " | ");
+
+    for (i = 0; i < ERTS_PSFLG_MAX && psflg; i++) {
+        erts_aint32_t chk = (1 << i);
+        if (psflg & chk) {
+            switch (chk) {
+            case ERTS_PSFLG_IN_PRQ_MAX:
+                erts_print(to, to_arg, "IN_PRQ_MAX"); break;
+            case ERTS_PSFLG_IN_PRQ_HIGH:
+                erts_print(to, to_arg, "IN_PRQ_HIGH"); break;
+            case ERTS_PSFLG_IN_PRQ_NORMAL:
+                erts_print(to, to_arg, "IN_PRQ_NORMAL"); break;
+            case ERTS_PSFLG_IN_PRQ_LOW:
+                erts_print(to, to_arg, "IN_PRQ_LOW"); break;
+            case ERTS_PSFLG_FREE:
+                erts_print(to, to_arg, "FREE"); break;
+            case ERTS_PSFLG_EXITING:
+                erts_print(to, to_arg, "EXITING"); break;
+            case ERTS_PSFLG_PENDING_EXIT:
+                erts_print(to, to_arg, "PENDING_EXIT"); break;
+            case ERTS_PSFLG_ACTIVE:
+                erts_print(to, to_arg, "ACTIVE"); break;
+            case ERTS_PSFLG_IN_RUNQ:
+                erts_print(to, to_arg, "IN_RUNQ"); break;
+            case ERTS_PSFLG_RUNNING:
+                erts_print(to, to_arg, "RUNNING"); break;
+            case ERTS_PSFLG_SUSPENDED:
+                erts_print(to, to_arg, "SUSPENDED"); break;
+            case ERTS_PSFLG_GC:
+                erts_print(to, to_arg, "GC"); break;
+            case ERTS_PSFLG_BOUND:
+                erts_print(to, to_arg, "BOUND"); break;
+            case ERTS_PSFLG_TRAP_EXIT:
+                erts_print(to, to_arg, "TRAP_EXIT"); break;
+            case ERTS_PSFLG_ACTIVE_SYS:
+                erts_print(to, to_arg, "ACTIVE_SYS"); break;
+            case ERTS_PSFLG_RUNNING_SYS:
+                erts_print(to, to_arg, "RUNNING_SYS"); break;
+            case ERTS_PSFLG_PROXY:
+                erts_print(to, to_arg, "PROXY"); break;
+            case ERTS_PSFLG_DELAYED_SYS:
+                erts_print(to, to_arg, "DELAYED_SYS"); break;
+#ifdef ERTS_DIRTY_SCHEDULERS
+            case ERTS_PSFLG_DIRTY_CPU_PROC:
+                erts_print(to, to_arg, "DIRTY_CPU_PROC"); break;
+            case ERTS_PSFLG_DIRTY_IO_PROC:
+                erts_print(to, to_arg, "DIRTY_IO_PROC"); break;
+            case ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q:
+                erts_print(to, to_arg, "DIRTY_CPU_PROC_IN_Q"); break;
+            case ERTS_PSFLG_DIRTY_IO_PROC_IN_Q:
+                erts_print(to, to_arg, "DIRTY_IO_PROC_IN_Q"); break;
+#endif
+            default:
+                erts_print(to, to_arg, "UNKNOWN(%d)", chk); break;
+            }
+            if (psflg > chk)
+                erts_print(to, to_arg, " | ");
+            psflg -= chk;
+        }
+    }
+    erts_print(to, to_arg, "\n");
+}
diff --git a/erts/emulator/beam/erl_thr_progress.c b/erts/emulator/beam/erl_thr_progress.c
index 664c479eb6..c2365c5cf7 100644
--- a/erts/emulator/beam/erl_thr_progress.c
+++ b/erts/emulator/beam/erl_thr_progress.c
@@ -1335,25 +1335,10 @@ erts_thr_progress_block(void)
     thr_progress_block(tmp_thr_prgr_data(NULL), 1);
 }
 
-void
-erts_thr_progress_fatal_error_block(SWord timeout,
-				    ErtsThrPrgrData *tmp_tpd_bufp)
+int
+erts_thr_progress_fatal_error_block(ErtsThrPrgrData *tmp_tpd_bufp)
 {
     ErtsThrPrgrData *tpd = perhaps_thr_prgr_data(NULL);
-    erts_aint32_t bc;
-    SWord time_left = timeout;
-    SysTimeval to;
-
-    /*
-     * Counting poll intervals may give us a too long timeout
-     * if cpu is busy. If we got tolerant time of day we use it
-     * to prevent this.
-     */
-    if (!erts_disable_tolerant_timeofday) {
-	erts_get_timeval(&to);
-	to.tv_sec += timeout / 1000;
-	to.tv_sec += timeout % 1000;
-    }
 
     if (!tpd) {
 	/*
@@ -1366,9 +1351,26 @@ erts_thr_progress_fatal_error_block(SWord timeout,
 	init_tmp_thr_prgr_data(tpd);
     }
 
-    bc = thr_progress_block(tpd, 0);
-    if (bc == 0)
-	return; /* Succefully blocked all managed threads */
+    /* Returns number of threads that have not yes been blocked */
+    return thr_progress_block(tpd, 0);
+}
+
+void
+erts_thr_progress_fatal_error_wait(SWord timeout) {
+    erts_aint32_t bc;
+    SWord time_left = timeout;
+    SysTimeval to;
+
+    /*
+     * Counting poll intervals may give us a too long timeout
+     * if cpu is busy. If we got tolerant time of day we use it
+     * to prevent this.
+     */
+    if (!erts_disable_tolerant_timeofday) {
+        erts_get_timeval(&to);
+        to.tv_sec += timeout / 1000;
+        to.tv_sec += timeout % 1000;
+    }
 
     while (1) {
 	if (erts_milli_sleep(ERTS_THR_PRGR_FTL_ERR_BLCK_POLL_INTERVAL) == 0)
diff --git a/erts/emulator/beam/erl_thr_progress.h b/erts/emulator/beam/erl_thr_progress.h
index 03ddbd467c..cf11c4e114 100644
--- a/erts/emulator/beam/erl_thr_progress.h
+++ b/erts/emulator/beam/erl_thr_progress.h
@@ -83,8 +83,8 @@ typedef struct {
     ErtsThrPrgrLeaderState leader_state;
 } ErtsThrPrgrData;
 
-void erts_thr_progress_fatal_error_block(SWord timeout,
-					 ErtsThrPrgrData *tmp_tpd_bufp);
+int erts_thr_progress_fatal_error_block(ErtsThrPrgrData *tmp_tpd_bufp);
+void erts_thr_progress_fatal_error_wait(SWord timeout);
 
 #endif /* ERTS_SMP */
 
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h
index 7214f3ea33..1fd800d524 100644
--- a/erts/emulator/beam/erl_threads.h
+++ b/erts/emulator/beam/erl_threads.h
@@ -476,6 +476,7 @@ ERTS_GLB_INLINE void erts_thr_detach(erts_tid_t tid);
 ERTS_GLB_INLINE void erts_thr_exit(void *res);
 ERTS_GLB_INLINE void erts_thr_install_exit_handler(void (*exit_handler)(void));
 ERTS_GLB_INLINE erts_tid_t erts_thr_self(void);
+ERTS_GLB_INLINE int erts_thr_getname(erts_tid_t tid, char *buf, size_t len);
 ERTS_GLB_INLINE int erts_equal_tids(erts_tid_t x, erts_tid_t y);
 ERTS_GLB_INLINE void erts_mtx_init_x(erts_mtx_t *mtx, char *name, Eterm extra,
 				     int enable_lcnt);
@@ -656,11 +657,17 @@ ERTS_GLB_INLINE void erts_thr_set_main_status(int, int);
 ERTS_GLB_INLINE int erts_thr_get_main_status(void);
 ERTS_GLB_INLINE void erts_thr_yield(void);
 
+
 #ifdef ETHR_HAVE_ETHR_SIG_FUNCS
 #define ERTS_THR_HAVE_SIG_FUNCS 1
 ERTS_GLB_INLINE void erts_thr_sigmask(int how, const sigset_t *set,
 				      sigset_t *oset);
 ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
+
+#ifdef USE_THREADS
+ERTS_GLB_INLINE void erts_thr_kill(erts_tid_t tid, int sig);
+#endif
+
 #endif /* #ifdef HAVE_ETHR_SIG_FUNCS */
 
 #ifdef USE_THREADS
@@ -2129,6 +2136,16 @@ erts_thr_self(void)
 #endif
 }
 
+ERTS_GLB_INLINE int
+erts_thr_getname(erts_tid_t tid, char *buf, size_t len)
+{
+#ifdef USE_THREADS
+    return ethr_getname(tid, buf, len);
+#else
+    return -1;
+#endif
+}
+
 
 ERTS_GLB_INLINE int
 erts_equal_tids(erts_tid_t x, erts_tid_t y)
@@ -3517,6 +3534,15 @@ ERTS_GLB_INLINE void erts_thr_yield(void)
 #ifdef ETHR_HAVE_ETHR_SIG_FUNCS
 
 ERTS_GLB_INLINE void
+erts_thr_kill(erts_tid_t tid, int sig) {
+#ifdef USE_THREADS
+  int res = ethr_kill((ethr_tid)tid, sig);
+  if (res)
+    erts_thr_fatal_error(res, "killing thread");
+#endif
+}
+
+ERTS_GLB_INLINE void
 erts_thr_sigmask(int how, const sigset_t *set, sigset_t *oset)
 {
 #ifdef USE_THREADS
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index eba07667ad..2f9969b0e7 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -3492,16 +3492,13 @@ init_sys_msg_dispatcher(void)
     thr_opts.coreNo   = 0;
 #endif
     thr_opts.detached = 1;
+    thr_opts.name = "sys_msg_dispatcher";
     init_smq_element_alloc();
     sys_message_queue = NULL;
     sys_message_queue_end = NULL;
     erts_smp_cnd_init(&smq_cnd);
     erts_smp_mtx_init(&smq_mtx, "sys_msg_q");
 
-#ifdef ETHR_HAVE_THREAD_NAMES
-    thr_opts.name = "sys_msg_dispatcher";
-#endif
-
     erts_smp_thr_create(&sys_msg_dispatcher_tid,
 			sys_msg_dispatcher_func,
 			NULL,
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 7661bf2dc7..828f5b427a 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -772,6 +772,8 @@ typedef struct {
 } ErtsCheckIoDebugInfo;
 int erts_check_io_debug(ErtsCheckIoDebugInfo *ip);
 
+int erts_sys_is_area_readable(char *start, char *stop);
+
 /* xxxP */
 #define SYS_DEFAULT_FLOAT_DECIMALS 20
 void init_sys_float(void);
@@ -800,6 +802,11 @@ int erts_sys_unsetenv(char *key);
 char *erts_read_env(char *key);
 void erts_free_read_env(void *value);
 
+#if defined(ERTS_THR_HAVE_SIG_FUNCS) && !defined(ETHR_UNUSABLE_SIGUSRX)
+extern void sys_thr_resume(erts_tid_t tid);
+extern void sys_thr_suspend(erts_tid_t tid);
+#endif
+
 /* utils.c */
 
 /* Options to sys_alloc_opt */
diff --git a/erts/emulator/drivers/unix/ttsl_drv.c b/erts/emulator/drivers/unix/ttsl_drv.c
index be2fee1f25..a5960716f2 100644
--- a/erts/emulator/drivers/unix/ttsl_drv.c
+++ b/erts/emulator/drivers/unix/ttsl_drv.c
@@ -338,8 +338,8 @@ static ErlDrvData ttysl_start(ErlDrvPort port, char* buf)
     }
 #endif
     DEBUGLOG(("utf8_mode is %s\n",(utf8_mode) ? "on" : "off"));
-    sys_sigset(SIGCONT, cont);
-    sys_sigset(SIGWINCH, winch);
+    sys_signal(SIGCONT, cont);
+    sys_signal(SIGWINCH, winch);
 
     driver_select(port, (ErlDrvEvent)(UWord)ttysl_fd, ERL_DRV_READ|ERL_DRV_USE, 1);
     ttysl_port = port;
@@ -423,8 +423,8 @@ static void ttysl_stop(ErlDrvData ttysl_data)
 	tty_reset(ttysl_fd);
 	driver_select(ttysl_port, (ErlDrvEvent)(UWord)ttysl_fd,
                       ERL_DRV_WRITE|ERL_DRV_READ|ERL_DRV_USE, 0);
-	sys_sigset(SIGCONT, SIG_DFL);
-	sys_sigset(SIGWINCH, SIG_DFL);
+	sys_signal(SIGCONT, SIG_DFL);
+	sys_signal(SIGWINCH, SIG_DFL);
     }
     ttysl_port = (ErlDrvPort)-1;
     ttysl_fd = -1;
@@ -1458,11 +1458,11 @@ static RETSIGTYPE suspend(int sig)
 	exit(1);
     }
 
-    sys_sigset(sig, SIG_DFL);	/* Set signal handler to default */
+    sys_signal(sig, SIG_DFL);	/* Set signal handler to default */
     sys_sigrelease(sig);	/* Allow 'sig' to come through */
     kill(getpid(), sig);	/* Send ourselves the signal */
     sys_sigblock(sig);		/* Reset to old mask */
-    sys_sigset(sig, suspend);	/* Reset signal handler */ 
+    sys_signal(sig, suspend);	/* Reset signal handler */ 
 
     if (tty_set(ttysl_fd) < 0) {
 	fprintf(stderr,"Can't set tty raw \n");
diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h
index b6bca5c0f4..f0050db114 100644
--- a/erts/emulator/sys/unix/erl_unix_sys.h
+++ b/erts/emulator/sys/unix/erl_unix_sys.h
@@ -45,7 +45,7 @@
 #include <fcntl.h>
 #include "erl_errno.h"
 #include <signal.h>
-
+#include <setjmp.h>
 
 #if HAVE_SYS_SOCKETIO_H
 #   include <sys/socketio.h>
@@ -211,13 +211,8 @@ int sys_stop_hrvtime(void);
 #define SYS_CLOCK_RESOLUTION 1
 
 /* These are defined in sys.c */
-#if defined(SIG_SIGSET)		/* Old SysV */
-RETSIGTYPE (*sys_sigset())();
-#elif defined(SIG_SIGNAL)	/* Old BSD */
-RETSIGTYPE (*sys_sigset())();
-#else
-RETSIGTYPE (*sys_sigset(int, RETSIGTYPE (*func)(int)))(int);
-#endif
+typedef void (*SIGFUNC)(int);
+extern SIGFUNC sys_signal(int, SIGFUNC);
 extern void sys_sigrelease(int);
 extern void sys_sigblock(int);
 extern void sys_stop_cat(void);
@@ -354,4 +349,28 @@ extern int exit_async(void);
 
 #define ERTS_EXIT_AFTER_DUMP _exit
 
+#if !defined(__APPLE__) && !defined(__MACH__)
+/* Some OS X versions do not allow (ab)using signal handlers like this */
+#define ERTS_HAVE_TRY_CATCH 1
+
+/* We try to simulate a try catch in C with the help of signal handlers.
+ * Only use this as a very last resort, as it is not very portable and
+ * quite unstable. It is also not thread safe, so make sure that only
+ * one thread can call this at a time!
+ */
+extern void erts_sys_sigsegv_handler(int);
+extern jmp_buf erts_sys_sigsegv_jmp;
+#define ERTS_SYS_TRY_CATCH(EXPR,CATCH)                                  \
+    do {                                                                \
+        SIGFUNC prev_handler = sys_signal(SIGSEGV,                      \
+                                          erts_sys_sigsegv_handler);    \
+        if (!setjmp(erts_sys_sigsegv_jmp)) {                            \
+            EXPR;                                                       \
+        } else {                                                        \
+            CATCH;                                                      \
+        }                                                               \
+        sys_signal(SIGSEGV,prev_handler);                               \
+    } while(0)
+#endif
+
 #endif /* #ifndef _ERL_UNIX_SYS_H */
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 47acd132ca..6248651882 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -224,10 +224,15 @@ static erts_smp_atomic_t sys_misc_mem_sz;
 #if defined(ERTS_SMP)
 static void smp_sig_notify(char c);
 static int sig_notify_fds[2] = {-1, -1};
+
+static int sig_suspend_fds[2] = {-1, -1};
+#define ERTS_SYS_SUSPEND_SIGNAL SIGUSR2
 #elif defined(USE_THREADS)
 static int async_fd[2];
 #endif
 
+jmp_buf erts_sys_sigsegv_jmp;
+
 #if CHLDWTHR || defined(ERTS_SMP)
 erts_mtx_t chld_stat_mtx;
 #endif
@@ -654,39 +659,7 @@ erl_sys_init(void)
 
 /* signal handling */
 
-#ifdef SIG_SIGSET		/* Old SysV */
-RETSIGTYPE (*sys_sigset(sig, func))()
-int sig;
-RETSIGTYPE (*func)();
-{
-    return(sigset(sig, func));
-}
-void sys_sigblock(int sig)
-{
-    sighold(sig);
-}
-void sys_sigrelease(int sig)
-{
-    sigrelse(sig);
-}
-#else /* !SIG_SIGSET */
-#ifdef SIG_SIGNAL		/* Old BSD */
-RETSIGTYPE (*sys_sigset(sig, func))(int, int)
-int sig;
-RETSIGTYPE (*func)();
-{
-    return(signal(sig, func));
-}
-sys_sigblock(int sig)
-{
-    sigblock(sig);
-}
-sys_sigrelease(int sig)
-{
-    sigsetmask(sigblock(0) & ~sigmask(sig));
-}
-#else /* !SIG_SIGNAL */	/* The True Way - POSIX!:-) */
-RETSIGTYPE (*sys_sigset(int sig, RETSIGTYPE (*func)(int)))(int)
+SIGFUNC sys_signal(int sig, SIGFUNC func)
 {
     struct sigaction act, oact;
 
@@ -719,23 +692,35 @@ void sys_sigrelease(int sig)
     sigaddset(&mask, sig);
     sigprocmask(SIG_UNBLOCK, &mask, (sigset_t *)NULL);
 }
-#endif /* !SIG_SIGNAL */
-#endif /* !SIG_SIGSET */
 
-#if (0) /* not used? -- gordon */
-static void (*break_func)();
-static RETSIGTYPE break_handler(int sig)
-{
-#ifdef QNX
-    /* Turn off SIGCHLD during break processing */
-    sys_sigblock(SIGCHLD);
-#endif
-    (*break_func)();
-#ifdef QNX
-    sys_sigrelease(SIGCHLD);
-#endif
+void erts_sys_sigsegv_handler(int signo) {
+    if (signo == SIGSEGV) {
+        longjmp(erts_sys_sigsegv_jmp, 1);
+    }
+}
+
+/*
+ * Function returns 1 if we can read from all values in between
+ * start and stop.
+ */
+int
+erts_sys_is_area_readable(char *start, char *stop) {
+    int fds[2];
+    if (!pipe(fds)) {
+        /* We let write try to figure out if the pointers are readable */
+        int res = write(fds[1], start, (char*)stop - (char*)start);
+        if (res == -1) {
+            close(fds[0]);
+            close(fds[1]);
+            return 0;
+        }
+        close(fds[0]);
+        close(fds[1]);
+        return 1;
+    }
+    return 0;
+
 }
-#endif /* 0 */
 
 static ERTS_INLINE int
 prepare_crash_dump(int secs)
@@ -797,6 +782,9 @@ prepare_crash_dump(int secs)
 	/* We don't want to close the signal notification pipe... */
 	if (i == sig_notify_fds[0] || i == sig_notify_fds[1])
 	    continue;
+	/* We don't want to close the signal syspend pipe... */
+	if (i == sig_suspend_fds[0] || i == sig_suspend_fds[1])
+	    continue;
 #elif defined(USE_THREADS)
 	/* We don't want to close the async notification pipe... */
 	if (i == async_fd[0] || i == async_fd[1])
@@ -885,9 +873,23 @@ sigusr1_exit(void)
 
 #ifdef ETHR_UNUSABLE_SIGUSRX
 #warning "Unusable SIGUSR1 & SIGUSR2. Disabling use of these signals"
-#endif
 
-#ifndef ETHR_UNUSABLE_SIGUSRX
+#else
+
+#ifdef ERTS_SMP
+void
+sys_thr_suspend(erts_tid_t tid) {
+    erts_thr_kill(tid, ERTS_SYS_SUSPEND_SIGNAL);
+}
+
+void
+sys_thr_resume(erts_tid_t tid) {
+    int i = 0, res;
+    do {
+        res = write(sig_suspend_fds[1],&i,sizeof(i));
+    } while (res < 0 && errno == EAGAIN);
+}
+#endif
 
 #if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
 static RETSIGTYPE user_signal1(void)
@@ -902,20 +904,20 @@ static RETSIGTYPE user_signal1(int signum)
 #endif
 }
 
-#ifdef QUANTIFY
+#ifdef ERTS_SMP
 #if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
-static RETSIGTYPE user_signal2(void)
+static RETSIGTYPE suspend_signal(void)
 #else
-static RETSIGTYPE user_signal2(int signum)
+static RETSIGTYPE suspend_signal(int signum)
 #endif
 {
-#ifdef ERTS_SMP
-   smp_sig_notify('2');
-#else
-   quantify_save_data();
-#endif
+   int res;
+   int buf[1];
+   do {
+     res = read(sig_suspend_fds[0], buf, sizeof(int));
+   } while (res < 0 && errno == EINTR);
 }
-#endif
+#endif /* #ifdef ERTS_SMP */
 
 #endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
 
@@ -940,9 +942,9 @@ static RETSIGTYPE do_quit(int signum)
 
 /* Disable break */
 void erts_set_ignore_break(void) {
-    sys_sigset(SIGINT,  SIG_IGN);
-    sys_sigset(SIGQUIT, SIG_IGN);
-    sys_sigset(SIGTSTP, SIG_IGN);
+    sys_signal(SIGINT,  SIG_IGN);
+    sys_signal(SIGQUIT, SIG_IGN);
+    sys_signal(SIGTSTP, SIG_IGN);
 }
 
 /* Don't use ctrl-c for break handler but let it be 
@@ -965,14 +967,14 @@ void erts_replace_intr(void) {
 
 void init_break_handler(void)
 {
-   sys_sigset(SIGINT, request_break);
+   sys_signal(SIGINT, request_break);
 #ifndef ETHR_UNUSABLE_SIGUSRX
-   sys_sigset(SIGUSR1, user_signal1);
-#ifdef QUANTIFY
-   sys_sigset(SIGUSR2, user_signal2);
-#endif
+   sys_signal(SIGUSR1, user_signal1);
+#ifdef ERTS_SMP
+   sys_signal(ERTS_SYS_SUSPEND_SIGNAL, suspend_signal);
+#endif /* #ifdef ERTS_SMP */
 #endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
-   sys_sigset(SIGQUIT, do_quit);
+   sys_signal(SIGQUIT, do_quit);
 }
 
 int sys_max_files(void)
@@ -989,8 +991,13 @@ static void block_signals(void)
    sys_sigblock(SIGINT);
 #ifndef ETHR_UNUSABLE_SIGUSRX
    sys_sigblock(SIGUSR1);
+#endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
+#endif /* #ifndef ERTS_SMP */
+
+#if defined(ERTS_SMP) && !defined(ETHR_UNUSABLE_SIGUSRX)
+   sys_sigblock(ERTS_SYS_SUSPEND_SIGNAL);
 #endif
-#endif
+
 }
 
 static void unblock_signals(void)
@@ -1004,8 +1011,14 @@ static void unblock_signals(void)
 #ifndef ETHR_UNUSABLE_SIGUSRX
    sys_sigrelease(SIGUSR1);
 #endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
+#endif /* #ifndef ERTS_SMP */
+
+#if defined(ERTS_SMP) && !defined(ETHR_UNUSABLE_SIGUSRX)
+   sys_sigrelease(ERTS_SYS_SUSPEND_SIGNAL);
 #endif
+
 }
+
 /************************** Time stuff **************************/
 #ifdef HAVE_GETHRTIME
 #ifdef GETHRTIME_WITH_CLOCK_GETTIME
@@ -1335,9 +1348,10 @@ static int spawn_init()
 
    thr_opts.detached = 0;
    thr_opts.suggested_stack_size = 0; /* Smallest possible */
+   thr_opts.name = "child_waiter";
 #endif
 
-   sys_sigset(SIGPIPE, SIG_IGN); /* Ignore - we'll handle the write failure */
+   sys_signal(SIGPIPE, SIG_IGN); /* Ignore - we'll handle the write failure */
    driver_data = (struct driver_data *)
        erts_alloc(ERTS_ALC_T_DRV_TAB, max_files * sizeof(struct driver_data));
    erts_smp_atomic_add_nob(&sys_misc_mem_sz,
@@ -1350,7 +1364,7 @@ static int spawn_init()
    sys_sigblock(SIGCHLD);
 #endif
 
-   sys_sigset(SIGCHLD, onchld); /* Reap children */
+   sys_signal(SIGCHLD, onchld); /* Reap children */
 
 #if CHLDWTHR
    erts_thr_create(&child_waiter_tid, child_waiter, NULL, &thr_opts);
@@ -3210,13 +3224,6 @@ signal_dispatcher_thread_func(void *unused)
 	    case '1': /* SIGUSR1 */
 		sigusr1_exit();
 		break;
-#ifdef QUANTIFY
-	    case '2': /* SIGUSR2 */
-		quantify_save_data(); /* Might take a substantial amount of
-					 time, but this is a test/debug
-					 build */
-		break;
-#endif
 	    default:
 		erl_exit(ERTS_ABORT_EXIT,
 			 "signal-dispatcher thread received unknown "
@@ -3234,6 +3241,7 @@ init_smp_sig_notify(void)
 {
     erts_smp_thr_opts_t thr_opts = ERTS_SMP_THR_OPTS_DEFAULT_INITER;
     thr_opts.detached = 1;
+    thr_opts.name = "sys_sig_dispatcher";
 
     if (pipe(sig_notify_fds) < 0) {
 	erl_exit(ERTS_ABORT_EXIT,
@@ -3248,6 +3256,17 @@ init_smp_sig_notify(void)
 			NULL,
 			&thr_opts);
 }
+
+static void
+init_smp_sig_suspend(void) {
+  if (pipe(sig_suspend_fds) < 0) {
+    erl_exit(ERTS_ABORT_EXIT,
+	     "Failed to create sig_suspend pipe: %s (%d)\n",
+	     erl_errno_id(errno),
+	     errno);
+  }
+}
+
 #ifdef __DARWIN__
 
 int erts_darwin_main_thread_pipe[2];
@@ -3275,9 +3294,11 @@ erts_sys_main_thread(void)
 #endif
 
     smp_sig_notify(0); /* Notify initialized */
-    while (1) {
-	/* Wait for a signal to arrive... */
+
+    /* Wait for a signal to arrive... */
+
 #ifdef __DARWIN__
+    while (1) {
 	/*
 	 * The wx driver needs to be able to steal the main thread for Cocoa to
 	 * work properly.
@@ -3292,12 +3313,24 @@ erts_sys_main_thread(void)
 	    void* (*func)(void*);
 	    void* arg;
 	    void *resp;
-	    read(erts_darwin_main_thread_pipe[0],&func,sizeof(void* (*)(void*)));
-	    read(erts_darwin_main_thread_pipe[0],&arg, sizeof(void*));
+            res = read(erts_darwin_main_thread_pipe[0],&func,sizeof(void* (*)(void*)));
+            if (res != sizeof(void* (*)(void*)))
+                break;
+            res = read(erts_darwin_main_thread_pipe[0],&arg,sizeof(void*));
+            if (res != sizeof(void*))
+                break;
 	    resp = (*func)(arg);
 	    write(erts_darwin_main_thread_result_pipe[1],&resp,sizeof(void *));
 	}
-#else
+
+        if (res == -1 && errno != EINTR)
+            break;
+    }
+    /* Something broke with the main thread pipe, so we ignore it for now.
+       Most probably erts has closed this pipe and is about to exit. */
+#endif /* #ifdef __DARWIN__ */
+
+    while (1) {
 #ifdef DEBUG
 	int res =
 #else
@@ -3306,7 +3339,6 @@ erts_sys_main_thread(void)
 	    select(0, NULL, NULL, NULL, NULL);
 	ASSERT(res < 0);
 	ASSERT(errno == EINTR);
-#endif
     }
 }
 
@@ -3398,6 +3430,7 @@ erl_sys_args(int* argc, char** argv)
 
 #ifdef ERTS_SMP
     init_smp_sig_notify();
+    init_smp_sig_suspend();
 #endif
 
     /* Handled arguments have been marked with NULL. Slide arguments
diff --git a/erts/emulator/sys/unix/sys_float.c b/erts/emulator/sys/unix/sys_float.c
index cafeab547e..2ffa649767 100644
--- a/erts/emulator/sys/unix/sys_float.c
+++ b/erts/emulator/sys/unix/sys_float.c
@@ -32,7 +32,7 @@ void
 erts_sys_init_float(void)
 {
 # ifdef SIGFPE
-    sys_sigset(SIGFPE, SIG_IGN); /* Ignore so we can test for NaN and Inf */
+    sys_signal(SIGFPE, SIG_IGN); /* Ignore so we can test for NaN and Inf */
 # endif
 }
 
@@ -667,7 +667,7 @@ static void fpe_sig_handler(int sig)
 
 static void erts_thread_catch_fp_exceptions(void)
 {
-    sys_sigset(SIGFPE, fpe_sig_handler);
+    sys_signal(SIGFPE, fpe_sig_handler);
     unmask_fpe();
 }
 
diff --git a/erts/emulator/sys/win32/erl_win_sys.h b/erts/emulator/sys/win32/erl_win_sys.h
index 838f0c61eb..fde32c8684 100644
--- a/erts/emulator/sys/win32/erl_win_sys.h
+++ b/erts/emulator/sys/win32/erl_win_sys.h
@@ -236,4 +236,16 @@ typedef long ssize_t;
 int init_async(int);
 int exit_async(void);
 #endif
+
+#define ERTS_HAVE_TRY_CATCH 1
+
+#define ERTS_SYS_TRY_CATCH(EXPR,CATCH)                                  \
+    __try {                                                             \
+    EXPR;                                                               \
+    }                                                                   \
+    __except(GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) \
+    {                                                                   \
+        CATCH;                                                          \
+    }
+
 #endif
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index 164ef95629..5d51659b4e 100644
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -247,6 +247,27 @@ void erl_sys_args(int* argc, char** argv)
 #endif
 }
 
+/*
+ * Function returns 1 if we can read from all values in between
+ * start and stop.
+ */
+int
+erts_sys_is_area_readable(char *start, char *stop) {
+    volatile char tmp;
+    __try
+    {
+        while(start < stop) {
+            tmp = *start;
+            start++;
+        }
+    }
+    __except(EXCEPTION_EXECUTE_HANDLER)
+    {
+        return 0;
+    }
+    return 1;
+}
+
 int erts_sys_prepare_crash_dump(int secs)
 {
     Port *heart_port;
diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl
index fbc229bc53..fc9bdae0a0 100644
--- a/erts/emulator/test/bif_SUITE.erl
+++ b/erts/emulator/test/bif_SUITE.erl
@@ -20,6 +20,7 @@
 -module(bif_SUITE).
 
 -include_lib("test_server/include/test_server.hrl").
+-include_lib("kernel/include/file.hrl").
 
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2,
@@ -681,8 +682,38 @@ erlang_halt(Config) when is_list(Config) ->
     {badrpc,nodedown} = rpc:call(N2, erlang, halt, [0]),
     {ok,N3} = slave:start(H, halt_node3),
     {badrpc,nodedown} = rpc:call(N3, erlang, halt, [0,[]]),
-    ok.
 
+    % This test triggers a segfault when dumping a crash dump
+    % to make sure that we can handle it properly.
+    {ok,N4} = slave:start(H, halt_node4),
+    CrashDump = filename:join(proplists:get_value(priv_dir,Config),
+                              "segfault_erl_crash.dump"),
+    true = rpc:call(N4, os, putenv, ["ERL_CRASH_DUMP",CrashDump]),
+    false = rpc:call(N4, erts_debug, set_internal_state,
+                     [available_internal_state, true]),
+    {badrpc,nodedown} = rpc:call(N4, erts_debug, set_internal_state,
+                                 [broken_halt, "Validate correct crash dump"]),
+    ok = wait_until_stable_size(CrashDump,-1),
+    {ok, Bin} = file:read_file(CrashDump),
+    case {string:str(binary_to_list(Bin),"\n=end\n"),
+          string:str(binary_to_list(Bin),"\r\n=end\r\n")} of
+        {0,0} -> ct:fail("Could not find end marker in crash dump");
+        _ -> ok
+    end.
+
+wait_until_stable_size(_File,-10) ->
+    {error,enoent};
+wait_until_stable_size(File,PrevSz) ->
+    timer:sleep(250),
+    case file:read_file_info(File) of
+        {error,enoent} ->
+            wait_until_stable_size(File,PrevSz-1);
+        {ok,#file_info{size = PrevSz }} when PrevSz /= -1 ->
+            io:format("Crashdump file size was: ~p (~s)~n",[PrevSz,File]),
+            ok;
+        {ok,#file_info{size = NewSz }} ->
+            wait_until_stable_size(File,NewSz)
+    end.
 
 
 %% Helpers