Merge branch 'rickard/ds-features-20'

OTP-14152

* rickard/ds-features-20:
  Remove experimental disclaimer on dirty schedulers
  Scheduler wall time support for dirty schedulers
  Always return info from system_info(dirty_[cpu|io]_schedulers*)
  Improve etp-commands
  Switch between scheduler types when multi-scheduling is blocked
  Perform potentially long GC on dirty schedulers if available
  Return and exception trace for nif-export scheduled BIFs
  Optimize handling of BIF errors
  Support for dirty BIFs
  Reduction counting on non-tail return

12 files changed, 743 insertions, 60 deletions

diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index 2e48c475d5..7c9927c4f3 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -53,6 +53,7 @@ MODULES= \
 	crypto_SUITE \
 	ddll_SUITE \
 	decode_packet_SUITE \
+	dirty_bif_SUITE \
 	dirty_nif_SUITE \
 	distribution_SUITE \
 	driver_SUITE \
diff --git a/erts/emulator/test/call_trace_SUITE.erl b/erts/emulator/test/call_trace_SUITE.erl
index f7ff04430a..2e303ba9a8 100644
--- a/erts/emulator/test/call_trace_SUITE.erl
+++ b/erts/emulator/test/call_trace_SUITE.erl
@@ -45,7 +45,7 @@ suite() ->
     [{ct_hooks,[ts_install_cth]},
      {timetrap, {seconds, 30}}].
 
-all() -> 
+all() ->
     Common = [errors, on_load],
     NotHipe = [process_specs, basic, flags, pam, change_pam,
                upgrade,
diff --git a/erts/emulator/test/dirty_bif_SUITE.erl b/erts/emulator/test/dirty_bif_SUITE.erl
new file mode 100644
index 0000000000..308323594d
--- /dev/null
+++ b/erts/emulator/test/dirty_bif_SUITE.erl
@@ -0,0 +1,583 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2010-2014. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(dirty_bif_SUITE).
+
+%%-define(line_trace,true).
+-define(CHECK(Exp,Got), check(Exp,Got,?LINE)).
+%%-define(CHECK(Exp,Got), Exp = Got).
+
+-include_lib("common_test/include/ct.hrl").
+
+-export([all/0, suite/0,
+	 init_per_suite/1, end_per_suite/1,
+	 init_per_testcase/2, end_per_testcase/2,
+	 dirty_bif/1, dirty_bif_exception/1,
+	 dirty_bif_multischedule/1,
+	 dirty_bif_multischedule_exception/1,
+	 dirty_scheduler_exit/1,
+	 dirty_call_while_terminated/1,
+	 dirty_heap_access/1,
+	 dirty_process_info/1,
+	 dirty_process_register/1,
+	 dirty_process_trace/1,
+	 code_purge/1]).
+
+suite() -> [{ct_hooks,[ts_install_cth]}].
+
+%%
+%% All these tests utilize the debug BIFs:
+%% - erts_debug:dirty_cpu/2 - Statically determined
+%%   to (begin to) execute on a dirty CPU scheduler.
+%% - erts_debug:dirty_io/2 - Statically determined
+%%   to (begin to) execute on a dirty IO scheduler.
+%% - erts_debug:dirty/3
+%% Their implementations are located in
+%% $ERL_TOP/erts/emulator/beam/beam_debug.c
+%%
+
+all() ->
+    [dirty_bif,
+     dirty_bif_multischedule,
+     dirty_bif_exception,
+     dirty_bif_multischedule_exception,
+     dirty_scheduler_exit,
+     dirty_call_while_terminated,
+     dirty_heap_access,
+     dirty_process_info,
+     dirty_process_register,
+     dirty_process_trace,
+     code_purge].
+
+init_per_suite(Config) ->
+    case erlang:system_info(dirty_cpu_schedulers) of
+	N when N > 0 ->
+	    Config;
+        _ ->
+	    {skipped, "No dirty scheduler support"}
+    end.
+
+end_per_suite(_Config) ->
+    ok.
+
+init_per_testcase(Case, Config) ->
+    [{testcase, Case} | Config].
+
+end_per_testcase(_Case, _Config) ->
+    ok.
+
+dirty_bif(Config) when is_list(Config) ->
+    dirty_cpu = erts_debug:dirty_cpu(scheduler,type),
+    dirty_io = erts_debug:dirty_io(scheduler,type),
+    normal = erts_debug:dirty(normal,scheduler,type),
+    dirty_cpu = erts_debug:dirty(dirty_cpu,scheduler,type),
+    dirty_io = erts_debug:dirty(dirty_io,scheduler,type),
+    ok.
+
+dirty_bif_multischedule(Config) when is_list(Config) ->
+    ok = erts_debug:dirty_cpu(reschedule,1000),
+    ok = erts_debug:dirty_io(reschedule,1000),
+    ok = erts_debug:dirty(normal,reschedule,1000),
+    ok.
+    
+
+dirty_bif_exception(Config) when is_list(Config) ->
+    lists:foreach(fun (Error) ->
+			  ErrorType = case Error of
+					  _ when is_atom(Error) -> Error;
+					  _ -> badarg
+				      end,
+			  try
+			      erts_debug:dirty_cpu(error, Error),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty_cpu,[error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      apply(erts_debug,dirty_cpu,[error, Error]),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty_cpu,[error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      erts_debug:dirty_io(error, Error),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty_io,[error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      apply(erts_debug,dirty_io,[error, Error]),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty_io,[error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      erts_debug:dirty(normal, error, Error),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[normal, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      apply(erts_debug,dirty,[normal, error, Error]),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[normal, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      erts_debug:dirty(dirty_cpu, error, Error),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[dirty_cpu, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      apply(erts_debug,dirty,[dirty_cpu, error, Error]),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[dirty_cpu, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      erts_debug:dirty(dirty_io, error, Error),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[dirty_io, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end,
+			  try
+			      apply(erts_debug,dirty,[dirty_io, error, Error]),
+			      ct:fail(expected_exception)
+			  catch
+			      error:ErrorType ->
+				  [{erts_debug,dirty,[dirty_io, error, Error],_}|_]
+				      = erlang:get_stacktrace(),
+				  ok
+			  end
+		  end,
+		  [badarg, undef, badarith, system_limit, noproc,
+		   make_ref(), {another, "heap", term_to_binary("term")}]),
+    ok.
+
+
+dirty_bif_multischedule_exception(Config) when is_list(Config) ->
+    try
+	erts_debug:dirty_cpu(reschedule,1001)
+    catch
+	error:badarg ->
+	    [{erts_debug,dirty_cpu,[reschedule, 1001],_}|_]
+		= erlang:get_stacktrace(),
+	    ok
+    end,
+    try
+	erts_debug:dirty_io(reschedule,1001)
+    catch
+	error:badarg ->
+	    [{erts_debug,dirty_io,[reschedule, 1001],_}|_]
+		= erlang:get_stacktrace(),
+	    ok
+    end,
+    try
+	erts_debug:dirty(normal,reschedule,1001)
+    catch
+	error:badarg ->
+	    [{erts_debug,dirty,[normal,reschedule,1001],_}|_]
+		= erlang:get_stacktrace(),
+	    ok
+    end.
+
+dirty_scheduler_exit(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config, "+SDio 1"),
+    [ok] = mcall(Node,
+                 [fun() ->
+			  Start = erlang:monotonic_time(millisecond),
+                          ok = test_dirty_scheduler_exit(),
+			  End = erlang:monotonic_time(millisecond),
+			  io:format("Time=~p ms~n", [End-Start]),
+			  ok
+                  end]),
+    stop_node(Node),
+    ok.
+
+test_dirty_scheduler_exit() ->
+    process_flag(trap_exit,true),
+    test_dse(10,[]).
+test_dse(0,Pids) ->
+    timer:sleep(100),
+    kill_dse(Pids,[]);
+test_dse(N,Pids) ->
+    Pid = spawn_link(fun () -> erts_debug:dirty_io(wait, 5000) end),
+    test_dse(N-1,[Pid|Pids]).
+
+kill_dse([],Killed) ->
+    wait_dse(Killed);
+kill_dse([Pid|Pids],AlreadyKilled) ->
+    exit(Pid,kill),
+    kill_dse(Pids,[Pid|AlreadyKilled]).
+
+wait_dse([]) ->
+    ok;
+wait_dse([Pid|Pids]) ->
+    receive
+        {'EXIT',Pid,Reason} ->
+	    killed = Reason
+    end,
+    wait_dse(Pids).
+
+dirty_call_while_terminated(Config) when is_list(Config) ->
+    Me = self(),
+    Bin = list_to_binary(lists:duplicate(4711, $r)),
+    {value, {BinAddr, 4711, 1}} = lists:keysearch(4711, 2,
+						  element(2,
+							  process_info(self(),
+								       binary))),
+    {Dirty, DM} = spawn_opt(fun () ->
+				    erts_debug:dirty_cpu(alive_waitexiting, Me),
+				    blipp:blupp(Bin)
+			    end,
+			    [monitor,link]),
+    receive {alive, Dirty} -> ok end,
+    {value, {BinAddr, 4711, 2}} = lists:keysearch(4711, 2,
+						  element(2,
+							  process_info(self(),
+								       binary))),
+    Reason = die_dirty_process,
+    OT = process_flag(trap_exit, true),
+    exit(Dirty, Reason),
+    receive
+	{'DOWN', DM, process, Dirty, R0} ->
+	    R0 = Reason
+    end,
+    receive
+	{'EXIT', Dirty, R1} ->
+	    R1 = Reason
+    end,
+    undefined = process_info(Dirty),
+    undefined = process_info(Dirty, status),
+    false = erlang:is_process_alive(Dirty),
+    false = lists:member(Dirty, processes()),
+    %% Binary still refered by Dirty process not yet cleaned up
+    %% since the dirty bif has not yet returned...
+    {value, {BinAddr, 4711, 2}} = lists:keysearch(4711, 2,
+						  element(2,
+							  process_info(self(),
+								       binary))),
+    receive after 2000 -> ok end,
+    receive
+	Msg ->
+	    ct:fail({unexpected_message, Msg})
+    after
+	0 ->
+	    ok
+    end,
+    {value, {BinAddr, 4711, 1}} = lists:keysearch(4711, 2,
+						  element(2,
+							  process_info(self(),
+								       binary))),
+    process_flag(trap_exit, OT),
+    try
+	blipp:blupp(Bin)
+    catch
+	_ : _ -> ok
+    end.
+
+dirty_heap_access(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config),
+    Me = self(),
+    RGL = rpc:call(Node,erlang,whereis,[init]),
+    Ref = rpc:call(Node,erlang,make_ref,[]),
+    Dirty = spawn_link(fun () ->
+			       Res = erts_debug:dirty_cpu(copy, Ref),
+			       garbage_collect(),
+			       Me ! {self(), Res},
+			       receive after infinity -> ok end
+		       end),
+    {N, R} = access_dirty_heap(Dirty, RGL, 0, 0),
+    receive
+	{_Pid, Res} ->
+	    1000 = length(Res),
+	    lists:foreach(fun (X) -> Ref = X end, Res)
+    end,
+    unlink(Dirty),
+    exit(Dirty, kill),
+    stop_node(Node),
+    {comment, integer_to_list(N) ++ " GL change loops; "
+     ++ integer_to_list(R) ++ " while running dirty"}.
+
+access_dirty_heap(Dirty, RGL, N, R) ->
+    case process_info(Dirty, status) of
+	{status, waiting} ->
+	    {N, R};
+	{status, Status} ->
+	    {group_leader, GL} = process_info(Dirty, group_leader),
+	    true = group_leader(RGL, Dirty),
+	    {group_leader, RGL} = process_info(Dirty, group_leader),
+	    true = group_leader(GL, Dirty),
+	    {group_leader, GL} = process_info(Dirty, group_leader),
+	    access_dirty_heap(Dirty, RGL, N+1, case Status of
+						   running ->
+						       R+1;
+						   _ ->
+						       R
+					       end)
+    end.
+
+%% These tests verify that processes that access a process executing a
+%% dirty BIF where the main lock is needed for that access do not get
+%% blocked. Each test passes its pid to dirty_sleeper, which sends an
+%% 'alive' message when it's running on a dirty scheduler and just before
+%% it starts a 6 second sleep. When it receives the message, it verifies
+%% that access to the dirty process is as it expects.  After the dirty
+%% process finishes its 6 second sleep but before it returns from the dirty
+%% scheduler, it sends a 'done' message. If the tester already received
+%% that message, the test fails because it means attempting to access the
+%% dirty process waited for that process to return to a regular scheduler,
+%% so verify that we haven't received that message, and also verify that
+%% the dirty process is still alive immediately after accessing it.
+dirty_process_info(Config) when is_list(Config) ->
+    access_dirty_process(
+      Config,
+      fun() -> ok end,
+      fun(BifPid) ->
+	      PI = process_info(BifPid),
+	      {current_function,{erts_debug,dirty_io,2}} =
+		  lists:keyfind(current_function, 1, PI),
+	      ok
+      end,
+      fun(_) -> ok end).
+
+dirty_process_register(Config) when is_list(Config) ->
+    access_dirty_process(
+      Config,
+      fun() -> ok end,
+      fun(BifPid) ->
+	      register(test_dirty_process_register, BifPid),
+	      BifPid = whereis(test_dirty_process_register),
+	      unregister(test_dirty_process_register),
+	      false = lists:member(test_dirty_process_register,
+				   registered()),
+	      ok
+      end,
+      fun(_) -> ok end).
+
+dirty_process_trace(Config) when is_list(Config) ->
+    access_dirty_process(
+      Config,
+      fun() ->
+	      erlang:trace_pattern({erts_debug,dirty_io,2},
+				   [{'_',[],[{return_trace}]}],
+				   [local,meta]),
+	      ok
+      end,
+      fun(BifPid) ->
+	      erlang:trace(BifPid, true, [call,timestamp]),
+	      ok
+      end,
+      fun(BifPid) ->
+	      receive
+		  {done, BifPid} ->
+		      receive
+			  {trace_ts,BifPid,call,{erts_debug,dirty_io,_},_} ->
+			      ok
+		      after
+			  0 ->
+			      error(missing_trace_call_message)
+		      end %%,
+		      %% receive
+		      %% 	  {trace_ts,BifPid,return_from,{erts_debug,dirty_io,2},
+		      %% 	   ok,_} ->
+		      %% 	      ok
+		      %% after
+		      %% 	  100 ->
+		      %% 	      error(missing_trace_return_message)
+		      %% end
+	      after
+		  6500 ->
+		      error(missing_done_message)
+	      end,
+	      ok
+      end).
+
+dirty_code_test_code() ->
+    "
+-module(dirty_code_test).
+
+-export([func/1]).
+
+func(Fun) ->
+  Fun(),
+  blipp:blapp().
+
+".
+
+code_purge(Config) when is_list(Config) ->
+    Path = ?config(data_dir, Config),
+    File = filename:join(Path, "dirty_code_test.erl"),
+    ok = file:write_file(File, dirty_code_test_code()),
+    {ok, dirty_code_test, Bin} = compile:file(File, [binary]),
+    {module, dirty_code_test} = erlang:load_module(dirty_code_test, Bin),
+    Start = erlang:monotonic_time(),
+    {Pid1, Mon1} = spawn_monitor(fun () ->
+				       dirty_code_test:func(fun () ->
+								    %% Sleep for 6 seconds
+								    %% in dirty bif...
+								    erts_debug:dirty_io(wait,6000)
+							    end)
+			       end),
+    {module, dirty_code_test} = erlang:load_module(dirty_code_test, Bin),
+    {Pid2, Mon2} = spawn_monitor(fun () ->
+				       dirty_code_test:func(fun () ->
+								    %% Sleep for 6 seconds
+								    %% in dirty bif...
+								    erts_debug:dirty_io(wait,6000)
+							    end)
+				 end),
+    receive
+	{'DOWN', Mon1, process, Pid1, _} ->
+	    ct:fail(premature_death)
+    after 100 ->
+	    ok
+    end,
+    true = erlang:purge_module(dirty_code_test),
+    receive
+	{'DOWN', Mon1, process, Pid1, Reason1} ->
+	    killed = Reason1
+    end,
+    receive
+	{'DOWN', Mon2, process, Pid2, _} ->
+	    ct:fail(premature_death)
+    after 100 ->
+	    ok
+    end,
+    true = erlang:delete_module(dirty_code_test),
+    receive
+	{'DOWN', Mon2, process, Pid2, _} ->
+	    ct:fail(premature_death)
+    after 100 ->
+	    ok
+    end,
+    true = erlang:purge_module(dirty_code_test),
+    receive
+	{'DOWN', Mon2, process, Pid2, Reason2} ->
+	    killed = Reason2
+    end,
+    End = erlang:monotonic_time(),
+    Time = erlang:convert_time_unit(End-Start, native, milli_seconds),
+    io:format("Time=~p~n", [Time]),
+    true = Time =< 1000,
+    ok.
+
+%%
+%% Internal...
+%%
+
+access_dirty_process(Config, Start, Test, Finish) ->
+    {ok, Node} = start_node(Config, ""),
+    [ok] = mcall(Node,
+		 [fun() ->
+			  ok = test_dirty_process_access(Start, Test, Finish)
+		  end]),
+    stop_node(Node),
+    ok.
+
+test_dirty_process_access(Start, Test, Finish) ->
+    ok = Start(),
+    Self = self(),
+    BifPid = spawn_link(fun() ->
+				ok = erts_debug:dirty_io(ready_wait6_done, Self)
+			end),
+    ok = receive
+	     {ready, BifPid} ->
+		 ok = Test(BifPid),
+		 receive
+		     {done, BifPid} ->
+			 error(dirty_process_info_blocked)
+		 after
+		     0 ->
+			 true = erlang:is_process_alive(BifPid),
+			 ok
+		 end
+	 after
+	     3000 ->
+		 error(timeout)
+	 end,
+    ok = Finish(BifPid).
+
+receive_any() ->
+    receive M -> M end.
+
+start_node(Config) ->
+    start_node(Config, "").
+
+start_node(Config, Args) when is_list(Config) ->
+    Pa = filename:dirname(code:which(?MODULE)),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(proplists:get_value(testcase, Config))
+			++ "-"
+			++ integer_to_list(erlang:system_time(second))
+			++ "-"
+			++ integer_to_list(erlang:unique_integer([positive]))),
+    test_server:start_node(Name, slave, [{args, "-pa "++Pa++" "++Args}]).
+
+stop_node(Node) ->
+    test_server:stop_node(Node).
+
+mcall(Node, Funs) ->
+    Parent = self(),
+    Refs = lists:map(fun (Fun) ->
+                             Ref = make_ref(),
+                             spawn_link(Node,
+                                        fun () ->
+                                                Res = Fun(),
+                                                unlink(Parent),
+                                                Parent ! {Ref, Res}
+                                        end),
+                             Ref
+                     end, Funs),
+    lists:map(fun (Ref) ->
+                      receive
+                          {Ref, Res} ->
+                              Res
+                      end
+              end, Refs).
diff --git a/erts/emulator/test/dirty_bif_SUITE_data/.gitignore b/erts/emulator/test/dirty_bif_SUITE_data/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/erts/emulator/test/dirty_bif_SUITE_data/.gitignore
diff --git a/erts/emulator/test/dirty_nif_SUITE.erl b/erts/emulator/test/dirty_nif_SUITE.erl
index a61fd92a18..991ba0acc8 100644
--- a/erts/emulator/test/dirty_nif_SUITE.erl
+++ b/erts/emulator/test/dirty_nif_SUITE.erl
@@ -54,8 +54,8 @@ all() ->
      dirty_nif_send_traced].
 
 init_per_suite(Config) ->
-    try erlang:system_info(dirty_cpu_schedulers) of
-	N when is_integer(N), N > 0 ->
+    case erlang:system_info(dirty_cpu_schedulers) of
+	N when N > 0 ->
 	    case lib_loaded() of
 		false ->
 		    ok = erlang:load_nif(
@@ -64,8 +64,8 @@ init_per_suite(Config) ->
 		true ->
 		    ok
 	    end,
-	    Config
-    catch _:_ ->
+	    Config;
+        _ ->
 	    {skipped, "No dirty scheduler support"}
     end.
 
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index 0d3910b2e2..36d512e388 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -1689,7 +1689,7 @@ consume_timeslice(Config) when is_list(Config) ->
 
 consume_timeslice_test(Config) when is_list(Config) ->
     ensure_lib_loaded(Config),
-    CONTEXT_REDS = 2000,
+    CONTEXT_REDS = 4000,
     Me = self(),
     Go = make_ref(),
     RedDiff = make_ref(),
diff --git a/erts/emulator/test/old_scheduler_SUITE.erl b/erts/emulator/test/old_scheduler_SUITE.erl
index ffe7d40139..8515a87df8 100644
--- a/erts/emulator/test/old_scheduler_SUITE.erl
+++ b/erts/emulator/test/old_scheduler_SUITE.erl
@@ -64,11 +64,11 @@ all() ->
 init_per_testcase(_Case, Config) ->
     %% main test process needs max prio
     Prio = process_flag(priority, max),
-    MS = erlang:system_flag(multi_scheduling, block),
+    MS = erlang:system_flag(multi_scheduling, block_normal),
     [{prio,Prio},{multi_scheduling, MS}|Config].
 
 end_per_testcase(_Case, Config) ->
-    erlang:system_flag(multi_scheduling, unblock),
+    erlang:system_flag(multi_scheduling, unblock_normal),
     Prio=proplists:get_value(prio, Config),
     process_flag(priority, Prio),
     ok.
diff --git a/erts/emulator/test/port_SUITE.erl b/erts/emulator/test/port_SUITE.erl
index 23594aa8c4..2a13b2d2f4 100644
--- a/erts/emulator/test/port_SUITE.erl
+++ b/erts/emulator/test/port_SUITE.erl
@@ -2066,13 +2066,13 @@ exit_status_msb_test(Config, SleepSecs) when is_list(Config) ->
     StartedTime = (erlang:monotonic_time(microsecond) - Start)/1000000,
     io:format("StartedTime = ~p~n", [StartedTime]),
     true = StartedTime < SleepSecs,
-    erlang:system_flag(multi_scheduling, block),
+    erlang:system_flag(multi_scheduling, block_normal),
     lists:foreach(fun (P) -> receive {P, done} -> ok end end, Procs),
     DoneTime = (erlang:monotonic_time(microsecond) - Start)/1000000,
     io:format("DoneTime = ~p~n", [DoneTime]),
     true = DoneTime > SleepSecs,
     ok = verify_multi_scheduling_blocked(),
-    erlang:system_flag(multi_scheduling, unblock),
+    erlang:system_flag(multi_scheduling, unblock_normal),
     case {length(lists:usort(lists:flatten(SIds))), NoSchedsOnln} of
         {N, N} ->
             ok;
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index 5712c9fa74..e14185e881 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -1028,9 +1028,9 @@ low_prio(Config) when is_list(Config) ->
 	1 ->
 	    ok = low_prio_test(Config);
 	_ -> 
-	    erlang:system_flag(multi_scheduling, block),
+	    erlang:system_flag(multi_scheduling, block_normal),
 	    ok = low_prio_test(Config),
-	    erlang:system_flag(multi_scheduling, unblock),
+	    erlang:system_flag(multi_scheduling, unblock_normal),
 	    {comment,
 		   "Test not written for SMP runtime system. "
 		   "Multi scheduling blocked during test."}
@@ -1097,9 +1097,9 @@ yield(Config) when is_list(Config) ->
 	     ++ ") is enabled. Testcase gets messed up by modfied "
 	     "timing."};
 	_ ->
-	    MS = erlang:system_flag(multi_scheduling, block),
+	    MS = erlang:system_flag(multi_scheduling, block_normal),
 	    yield_test(),
-	    erlang:system_flag(multi_scheduling, unblock),
+	    erlang:system_flag(multi_scheduling, unblock_normal),
 	    case MS of
 		blocked ->
 		    {comment,
@@ -1679,7 +1679,7 @@ processes_bif_test() ->
 	true ->
 	    %% Do it again with a process suspended while
 	    %% in the processes/0 bif.
-	    erlang:system_flag(multi_scheduling, block),
+	    erlang:system_flag(multi_scheduling, block_normal),
 	    Suspendee = spawn_link(fun () ->
 						 Tester ! {suspend_me, self()},
 						 Tester ! {self(),
@@ -1692,7 +1692,7 @@ processes_bif_test() ->
 					 end),
 	    receive {suspend_me, Suspendee} -> ok end,
 	    erlang:suspend_process(Suspendee),
-	    erlang:system_flag(multi_scheduling, unblock),
+	    erlang:system_flag(multi_scheduling, unblock_normal),
 	    
 	    [{status,suspended},{current_function,{erlang,ptab_list_continue,2}}] =
 		process_info(Suspendee, [status, current_function]),
@@ -1732,10 +1732,10 @@ do_processes_bif_test(WantReds, DieTest, Processes) ->
 		    Splt = NoTestProcs div 10,
 		    {TP1, TP23} = lists:split(Splt, TestProcs),
 		    {TP2, TP3} = lists:split(Splt, TP23),
-		    erlang:system_flag(multi_scheduling, block),
+		    erlang:system_flag(multi_scheduling, block_normal),
 		    Tester ! DoIt,
 		    receive GetGoing -> ok end,
-		    erlang:system_flag(multi_scheduling, unblock),
+		    erlang:system_flag(multi_scheduling, unblock_normal),
 		    SpawnProcesses(high),
 		    lists:foreach( fun (P) ->
 				SpawnHangAround(),
@@ -1944,7 +1944,7 @@ processes_gc_trap(Config) when is_list(Config) ->
 	    processes()
     end,
 
-    erlang:system_flag(multi_scheduling, block),
+    erlang:system_flag(multi_scheduling, block_normal),
     Suspendee = spawn_link(fun () ->
 					 Tester ! {suspend_me, self()},
 					 Tester ! {self(),
@@ -1954,7 +1954,7 @@ processes_gc_trap(Config) when is_list(Config) ->
 				 end),
     receive {suspend_me, Suspendee} -> ok end,
     erlang:suspend_process(Suspendee),
-    erlang:system_flag(multi_scheduling, unblock),
+    erlang:system_flag(multi_scheduling, unblock_normal),
 	    
     [{status,suspended}, {current_function,{erlang,ptab_list_continue,2}}]
 	= process_info(Suspendee, [status, current_function]),
@@ -2161,7 +2161,7 @@ processes_term_proc_list_test(MustChk) ->
 		end)
     end,
     SpawnSuspendProcessesProc = fun () ->
-		  erlang:system_flag(multi_scheduling, block),
+		  erlang:system_flag(multi_scheduling, block_normal),
 		  P = spawn_link(fun () ->
 					 Tester ! {suspend_me, self()},
 					 Tester ! {self(),
@@ -2171,7 +2171,7 @@ processes_term_proc_list_test(MustChk) ->
 				 end),
 		  receive {suspend_me, P} -> ok end,
 		  erlang:suspend_process(P),
-		  erlang:system_flag(multi_scheduling, unblock),
+		  erlang:system_flag(multi_scheduling, unblock_normal),
 		  [{status,suspended},
 		   {current_function,{erlang,ptab_list_continue,2}}]
 		      = process_info(P, [status, current_function]),
@@ -2232,7 +2232,7 @@ processes_term_proc_list_test(MustChk) ->
     S8 = SpawnSuspendProcessesProc(),
     ?CHK_TERM_PROC_LIST(MustChk, 7),
 
-    erlang:system_flag(multi_scheduling, block),
+    erlang:system_flag(multi_scheduling, block_normal),
     Exit(S8),
     ?CHK_TERM_PROC_LIST(MustChk, 7),
     Exit(S5),
@@ -2241,7 +2241,7 @@ processes_term_proc_list_test(MustChk) ->
     ?CHK_TERM_PROC_LIST(MustChk, 6),
     Exit(S6),
     ?CHK_TERM_PROC_LIST(MustChk, 0),
-    erlang:system_flag(multi_scheduling, unblock),
+    erlang:system_flag(multi_scheduling, unblock_normal),
     as_expected.
 
 
diff --git a/erts/emulator/test/scheduler_SUITE.erl b/erts/emulator/test/scheduler_SUITE.erl
index 3aee15a8fc..b178dede5b 100644
--- a/erts/emulator/test/scheduler_SUITE.erl
+++ b/erts/emulator/test/scheduler_SUITE.erl
@@ -1095,16 +1095,13 @@ scheduler_threads(Config) when is_list(Config) ->
     end.
 
 dirty_scheduler_threads(Config) when is_list(Config) ->
-    SmpSupport = erlang:system_info(smp_support),
-    try
-	erlang:system_info(dirty_cpu_schedulers),
-	dirty_scheduler_threads_test(Config, SmpSupport)
-    catch
-	error:badarg ->
-	    {skipped, "No dirty scheduler support"}
+    case erlang:system_info(dirty_cpu_schedulers) of
+        0 -> {skipped, "No dirty scheduler support"};
+        _ -> dirty_scheduler_threads_test(Config)
     end.
 
-dirty_scheduler_threads_test(Config, SmpSupport) ->
+dirty_scheduler_threads_test(Config) ->
+    SmpSupport = erlang:system_info(smp_support),
     {Sched, SchedOnln, _} = get_dsstate(Config, ""),
     {HalfSched, HalfSchedOnln} = case SmpSupport of
                                      false -> {1,1};
@@ -1374,12 +1371,9 @@ sst2_loop(N) ->
     sst2_loop(N-1).
 
 sst3_loop(S, N) ->
-    try erlang:system_info(dirty_cpu_schedulers) of
-	DS ->
-	    sst3_loop_with_dirty_schedulers(S, DS, N)
-    catch
-	error:badarg ->
-	    sst3_loop_normal_schedulers_only(S, N)
+    case erlang:system_info(dirty_cpu_schedulers) of
+        0 -> sst3_loop_normal_schedulers_only(S, N);
+	DS -> sst3_loop_with_dirty_schedulers(S, DS, N)
     end.
 
 sst3_loop_normal_schedulers_only(_S, 0) ->
diff --git a/erts/emulator/test/statistics_SUITE.erl b/erts/emulator/test/statistics_SUITE.erl
index a1f12ba93c..f51244485b 100644
--- a/erts/emulator/test/statistics_SUITE.erl
+++ b/erts/emulator/test/statistics_SUITE.erl
@@ -28,6 +28,8 @@
 	 runtime_update/1, runtime_diff/1,
 	 run_queue_one/1,
 	 scheduler_wall_time/1,
+         scheduler_wall_time_all/1,
+         msb_scheduler_wall_time/1,
 	 reductions/1, reductions_big/1, garbage_collection/1, io/1,
 	 badarg/1, run_queues_lengths_active_tasks/1, msacc/1]).
 
@@ -43,7 +45,9 @@ suite() ->
 
 all() -> 
     [{group, wall_clock}, {group, runtime}, reductions,
-     reductions_big, {group, run_queue}, scheduler_wall_time,
+     reductions_big, {group, run_queue},
+     scheduler_wall_time, scheduler_wall_time_all,
+     msb_scheduler_wall_time,
      garbage_collection, io, badarg,
      run_queues_lengths_active_tasks,
      msacc].
@@ -271,35 +275,64 @@ hog_iter(0, Mon) ->
 
 %% Tests that statistics(scheduler_wall_time) works as intended
 scheduler_wall_time(Config) when is_list(Config) ->
+    scheduler_wall_time_test(scheduler_wall_time).
+
+%% Tests that statistics(scheduler_wall_time_all) works as intended
+scheduler_wall_time_all(Config) when is_list(Config) ->
+    scheduler_wall_time_test(scheduler_wall_time_all).
+
+scheduler_wall_time_test(Type) ->
     %% Should return undefined if system_flag is not turned on yet
-    undefined = statistics(scheduler_wall_time),
+    undefined = statistics(Type),
     %% Turn on statistics
     false = erlang:system_flag(scheduler_wall_time, true),
     try
         Schedulers = erlang:system_info(schedulers_online),
+        DirtyCPUSchedulers = erlang:system_info(dirty_cpu_schedulers_online),
+        DirtyIOSchedulers = erlang:system_info(dirty_io_schedulers),
+        TotLoadSchedulers = case Type of
+                                scheduler_wall_time_all ->
+                                    Schedulers + DirtyCPUSchedulers + DirtyIOSchedulers;
+                                scheduler_wall_time ->
+                                    Schedulers + DirtyCPUSchedulers
+                        end,
+                            
         %% Let testserver and everyone else finish their work
         timer:sleep(1500),
         %% Empty load
-        EmptyLoad = get_load(),
+        EmptyLoad = get_load(Type),
         {false, _} = {lists:any(fun(Load) -> Load > 50 end, EmptyLoad),EmptyLoad},
         MeMySelfAndI = self(),
         StartHog = fun() ->
-                           Pid = spawn(?MODULE, hog, [self()]),
+                           Pid = spawn_link(?MODULE, hog, [self()]),
                            receive hog_started -> MeMySelfAndI ! go end,
                            Pid
                    end,
+        StartDirtyHog = fun(Func) ->
+                                F = fun () ->
+                                            erts_debug:Func(alive_waitexiting,
+                                                            MeMySelfAndI)
+                                    end,
+                                Pid = spawn_link(F),
+                                receive {alive, Pid} -> ok end,
+                                Pid
+                        end,
         P1 = StartHog(),
         %% Max on one, the other schedulers empty (hopefully)
         %% Be generous the process can jump between schedulers
         %% which is ok and we don't want the test to fail for wrong reasons
-        _L1 = [S1Load|EmptyScheds1] = get_load(),
+        _L1 = [S1Load|EmptyScheds1] = get_load(Type),
         {true,_}  = {S1Load > 50,S1Load},
         {false,_} = {lists:any(fun(Load) -> Load > 50 end, EmptyScheds1),EmptyScheds1},
         {true,_}  = {lists:sum(EmptyScheds1) < 60,EmptyScheds1},
 
         %% 50% load
         HalfHogs = [StartHog() || _ <- lists:seq(1, (Schedulers-1) div 2)],
-        HalfLoad = lists:sum(get_load()) div Schedulers,
+        HalfDirtyCPUHogs = [StartDirtyHog(dirty_cpu)
+                            || _ <- lists:seq(1, DirtyCPUSchedulers div 2)],
+        HalfDirtyIOHogs = [StartDirtyHog(dirty_io)
+                           || _ <- lists:seq(1, DirtyIOSchedulers div 2)],
+        HalfLoad = lists:sum(get_load(Type)) div TotLoadSchedulers,
         if Schedulers < 2, HalfLoad > 80 -> ok; %% Ok only one scheduler online and one hog
            %% We want roughly 50% load
            HalfLoad > 40, HalfLoad < 60 -> ok;
@@ -308,23 +341,30 @@ scheduler_wall_time(Config) when is_list(Config) ->
 
         %% 100% load
         LastHogs = [StartHog() || _ <- lists:seq(1, Schedulers div 2)],
-        FullScheds = get_load(),
+        LastDirtyCPUHogs = [StartDirtyHog(dirty_cpu)
+                            || _ <- lists:seq(1, DirtyCPUSchedulers div 2)],
+        LastDirtyIOHogs = [StartDirtyHog(dirty_io)
+                           || _ <- lists:seq(1, DirtyIOSchedulers div 2)],
+        FullScheds = get_load(Type),
         {false,_} = {lists:any(fun(Load) -> Load < 80 end, FullScheds),FullScheds},
-        FullLoad = lists:sum(FullScheds) div Schedulers,
+        FullLoad = lists:sum(FullScheds) div TotLoadSchedulers,
         if FullLoad > 90 -> ok;
            true -> exit({fullload, FullLoad})
         end,
 
 	KillHog = fun (HP) ->
 			  HPM = erlang:monitor(process, HP),
+                          unlink(HP),
 			  exit(HP, kill),
 			  receive
 			      {'DOWN', HPM, process, HP, killed} ->
 				  ok
 			  end
 		  end,
-        [KillHog(Pid) || Pid <- [P1|HalfHogs++LastHogs]],
-        AfterLoad = get_load(),
+        [KillHog(Pid) || Pid <- [P1|HalfHogs++HalfDirtyCPUHogs++HalfDirtyIOHogs
+                                 ++LastHogs++LastDirtyCPUHogs++LastDirtyIOHogs]],
+        receive after 2000 -> ok end, %% Give dirty schedulers time to complete...
+        AfterLoad = get_load(Type),
 	io:format("AfterLoad=~p~n", [AfterLoad]),
         {false,_} = {lists:any(fun(Load) -> Load > 25 end, AfterLoad),AfterLoad},
         true = erlang:system_flag(scheduler_wall_time, false)
@@ -332,16 +372,81 @@ scheduler_wall_time(Config) when is_list(Config) ->
         erlang:system_flag(scheduler_wall_time, false)
     end.
 
-get_load() ->
-    Start = erlang:statistics(scheduler_wall_time),
+get_load(Type) ->
+    Start = erlang:statistics(Type),
     timer:sleep(1500),
-    End = erlang:statistics(scheduler_wall_time),
+    End = erlang:statistics(Type),
     lists:reverse(lists:sort(load_percentage(lists:sort(Start),lists:sort(End)))).
 
 load_percentage([{Id, WN, TN}|Ss], [{Id, WP, TP}|Ps]) ->
     [100*(WN-WP) div (TN-TP)|load_percentage(Ss, Ps)];
 load_percentage([], []) -> [].
 
+count(0) ->
+    ok;
+count(N) ->
+    count(N-1).
+
+msb_swt_hog(true) ->
+    count(1000000),
+    erts_debug:dirty_cpu(wait, 10),
+    erts_debug:dirty_io(wait, 10),
+    msb_swt_hog(true);
+msb_swt_hog(false) ->
+    count(1000000),
+    msb_swt_hog(false).
+
+msb_scheduler_wall_time(Config) ->
+    erlang:system_flag(scheduler_wall_time, true),
+    Dirty = erlang:system_info(dirty_cpu_schedulers) /= 0,
+    Hogs = lists:map(fun (_) ->
+                             spawn_opt(fun () ->
+                                               msb_swt_hog(Dirty)
+                                       end, [{priority,low}, link, monitor])
+                     end, lists:seq(1,10)),
+    erlang:system_flag(multi_scheduling, block),
+    try
+        SWT1 = lists:sort(statistics(scheduler_wall_time_all)),
+        %% io:format("SWT1 = ~p~n", [SWT1]),
+        receive after 4000 -> ok end,
+        SWT2 = lists:sort(statistics(scheduler_wall_time_all)),
+        %% io:format("SWT2 = ~p~n", [SWT2]),
+        SWT = lists:zip(SWT1, SWT2),
+        io:format("SU = ~p~n", [lists:map(fun({{I, A0, T0}, {I, A1, T1}}) ->
+                                                  {I, (A1 - A0)/(T1 - T0)} end,
+                                         SWT)]),
+        {A, T} = lists:foldl(fun({{_, A0, T0}, {_, A1, T1}}, {Ai,Ti}) ->
+                                     {Ai + (A1 - A0), Ti + (T1 - T0)}
+                             end,
+                             {0, 0},
+                             SWT),
+        TSU = A/T,
+        WSU = ((TSU * (erlang:system_info(schedulers)
+                       + erlang:system_info(dirty_cpu_schedulers)
+                       + erlang:system_info(dirty_io_schedulers)))
+               / 1),
+        %% Weighted scheduler utilization should be
+        %% very close to 1.0, i.e., we execute the
+        %% same time as one thread executing all
+        %% the time...
+        io:format("WSU = ~p~n", [WSU]),
+        true = 0.9 < WSU andalso WSU < 1.1,
+        ok
+    after
+        erlang:system_flag(multi_scheduling, unblock),
+        erlang:system_flag(scheduler_wall_time, false),
+        lists:foreach(fun ({HP, _HM}) ->
+                              unlink(HP),
+                              exit(HP, kill)
+                      end, Hogs),
+        lists:foreach(fun ({HP, HM}) ->
+                              receive
+                                  {'DOWN', HM, process, HP, _} ->
+                                      ok
+                              end
+                      end, Hogs),
+        ok
+    end.
 
 %% Tests that statistics(garbage_collection) is callable.
 %% It is not clear how to test anything more.
diff --git a/erts/emulator/test/z_SUITE.erl b/erts/emulator/test/z_SUITE.erl
index ab56018373..d663cc548c 100644
--- a/erts/emulator/test/z_SUITE.erl
+++ b/erts/emulator/test/z_SUITE.erl
@@ -68,8 +68,8 @@ schedulers_alive(Config) when is_list(Config) ->
               enabled ->
                   io:format("Testing blocking process exit~n"),
                   BF = fun () ->
-                               blocked = erlang:system_flag(multi_scheduling,
-                                                            block),
+                               blocked_normal = erlang:system_flag(multi_scheduling,
+								   block_normal),
                                Master ! {self(), blocking},
                                receive after infinity -> ok end
                        end,
@@ -77,21 +77,21 @@ schedulers_alive(Config) when is_list(Config) ->
                   Mon = erlang:monitor(process, Blocker),
                   receive {Blocker, blocking} -> ok end,
                   [Blocker]
-                  = erlang:system_info(multi_scheduling_blockers),
+                  = erlang:system_info(normal_multi_scheduling_blockers),
                   unlink(Blocker),
                   exit(Blocker, kill),
                   receive {'DOWN', Mon, _, _, _} -> ok end,
                   enabled = erlang:system_info(multi_scheduling),
-                  [] = erlang:system_info(multi_scheduling_blockers),
+                  [] = erlang:system_info(normal_multi_scheduling_blockers),
                   ok
           end,
           io:format("Testing blocked~n"),
-          erlang:system_flag(multi_scheduling, block),
+          erlang:system_flag(multi_scheduling, block_normal),
           case erlang:system_info(multi_scheduling) of
               enabled ->
                   ct:fail(multi_scheduling_enabled);
-              blocked ->
-                  [Master] = erlang:system_info(multi_scheduling_blockers);
+              blocked_normal ->
+                  [Master] = erlang:system_info(normal_multi_scheduling_blockers);
               disabled -> ok
           end,
           Ps = lists:map(
@@ -109,8 +109,8 @@ schedulers_alive(Config) when is_list(Config) ->
                                 unlink(P),
                                 exit(P, bang)
                         end, Ps),
-          case erlang:system_flag(multi_scheduling, unblock) of
-              blocked -> ct:fail(multi_scheduling_blocked);
+          case erlang:system_flag(multi_scheduling, unblock_normal) of
+              blocked_normal -> ct:fail(multi_scheduling_blocked);
               disabled -> ok;
               enabled -> ok
           end,