Merge branch 'bjorn/cuddle-with-tests'

* bjorn/cuddle-with-tests:
  Stabilize call_with_huge_message_queue/1
  same_time_yielding/1: Avoid failing if there are many schedulers
  Remove obsolete old_scheduler_SUITE
  Robustify process_SUITE:spawn_opt_max_heap_size/1
  Contain damage cause by spawn_opt_max_heap_size failing
  Make bulk_send_bigbig/1 purely informational
  distribution_SUITE: Refactor bulk_send_bigbig/1
  receive_SUITE: Remove ?line macros
  Lengthen too short timetraps
  Fix process_SUITE:low_prio/1

18 files changed, 187 insertions, 524 deletions

diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index 2479ccc01f..fcd7244ae9 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -117,7 +117,6 @@ MODULES= \
 	tracer_SUITE \
 	tracer_test \
 	scheduler_SUITE \
-	old_scheduler_SUITE \
 	port_trace_SUITE \
 	unique_SUITE \
 	z_SUITE \
diff --git a/erts/emulator/test/bs_construct_SUITE.erl b/erts/emulator/test/bs_construct_SUITE.erl
index ed03284a5b..779d81daa5 100644
--- a/erts/emulator/test/bs_construct_SUITE.erl
+++ b/erts/emulator/test/bs_construct_SUITE.erl
@@ -35,7 +35,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [test1, test2, test3, test4, test5, testf, not_used,
diff --git a/erts/emulator/test/call_trace_SUITE.erl b/erts/emulator/test/call_trace_SUITE.erl
index 95171d04ce..1251d644ae 100644
--- a/erts/emulator/test/call_trace_SUITE.erl
+++ b/erts/emulator/test/call_trace_SUITE.erl
@@ -43,7 +43,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 30}}].
+     {timetrap, {minutes, 2}}].
 
 all() ->
     Common = [errors, on_load],
diff --git a/erts/emulator/test/ddll_SUITE.erl b/erts/emulator/test/ddll_SUITE.erl
index 0b9f76a892..031b05790d 100644
--- a/erts/emulator/test/ddll_SUITE.erl
+++ b/erts/emulator/test/ddll_SUITE.erl
@@ -55,7 +55,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [ddll_test, errors, reference_count, kill_port,
diff --git a/erts/emulator/test/distribution_SUITE.erl b/erts/emulator/test/distribution_SUITE.erl
index 434e729310..dc7afa381b 100644
--- a/erts/emulator/test/distribution_SUITE.erl
+++ b/erts/emulator/test/distribution_SUITE.erl
@@ -62,8 +62,7 @@
 -export([sender/3, receiver2/2, dummy_waiter/0, dead_process/0,
          roundtrip/1, bounce/1, do_dist_auto_connect/1, inet_rpc_server/1,
          dist_parallel_sender/3, dist_parallel_receiver/0,
-         dist_evil_parallel_receiver/0,
-         sendersender/4, sendersender2/4]).
+         dist_evil_parallel_receiver/0]).
 
 %% epmd_module exports
 -export([start_link/0, register_node/2, register_node/3, port_please/2]).
@@ -129,52 +128,53 @@ bulk_send_small(Config) when is_list(Config) ->
 bulk_send_big(Config) when is_list(Config) ->
     bulk_send(32, 64).
 
-bulk_send_bigbig(Config) when is_list(Config) ->
-    bulk_sendsend(32*5, 4).
-
 bulk_send(Terms, BinSize) ->
     ct:timetrap({seconds, 30}),
 
     io:format("Sending ~w binaries, each of size ~w K", [Terms, BinSize]),
     {ok, Node} = start_node(bulk_receiver),
     Recv = spawn(Node, erlang, apply, [fun receiver/2, [0, 0]]),
-    Bin = list_to_binary(lists:duplicate(BinSize*1024, 253)),
+    Bin = binary:copy(<<253>>, BinSize*1024),
     Size = Terms*size(Bin),
     {Elapsed, {Terms, Size}} = test_server:timecall(?MODULE, sender,
                                                     [Recv, Bin, Terms]),
     stop_node(Node),
-    {comment, integer_to_list(trunc(Size/1024/max(1,Elapsed)+0.5)) ++ " K/s"}.
+    {comment, integer_to_list(round(Size/1024/max(1,Elapsed))) ++ " K/s"}.
 
-bulk_sendsend(Terms, BinSize) ->
+sender(To, _Bin, 0) ->
+    To ! {done, self()},
+    receive
+        Any ->
+            Any
+    end;
+sender(To, Bin, Left) ->
+    To ! {term, Bin},
+    sender(To, Bin, Left-1).
+
+bulk_send_bigbig(Config) when is_list(Config) ->
+    Terms = 32*5,
+    BinSize = 4,
     {Rate1, MonitorCount1} = bulk_sendsend2(Terms, BinSize,   5),
     {Rate2, MonitorCount2} = bulk_sendsend2(Terms, BinSize, 995),
     Ratio = if MonitorCount2 == 0 -> MonitorCount1 / 1.0;
                true               -> MonitorCount1 / MonitorCount2
             end,
-    Comment = integer_to_list(Rate1) ++ " K/s, " ++
-    integer_to_list(Rate2) ++ " K/s, " ++
-    integer_to_list(MonitorCount1) ++ " monitor msgs, " ++
-    integer_to_list(MonitorCount2) ++ " monitor msgs, " ++
-    float_to_list(Ratio) ++ " monitor ratio",
-    if
-        %% A somewhat arbitrary ratio, but hopefully one that will
-        %% accommodate a wide range of CPU speeds.
-        Ratio > 8.0 ->
-            {comment,Comment};
-        true ->
-            io:put_chars(Comment),
-            ct:fail(ratio_too_low)
-    end.
+    Comment0 = io_lib:format("~p K/s, ~p K/s, "
+                             "~p monitor msgs, ~p monitor msgs, "
+                             "~.1f monitor ratio",
+                             [Rate1,Rate2,MonitorCount1,
+                              MonitorCount2,Ratio]),
+    Comment = lists:flatten(Comment0),
+    {comment,Comment}.
 
 bulk_sendsend2(Terms, BinSize, BusyBufSize) ->
     ct:timetrap({seconds, 30}),
 
-    io:format("Sending ~w binaries, each of size ~w K",
+    io:format("\nSending ~w binaries, each of size ~w K",
               [Terms, BinSize]),
     {ok, NodeRecv} = start_node(bulk_receiver),
     Recv = spawn(NodeRecv, erlang, apply, [fun receiver/2, [0, 0]]),
-    Bin = list_to_binary(lists:duplicate(BinSize*1024, 253)),
-    %%Size = Terms*size(Bin),
+    Bin = binary:copy(<<253>>, BinSize*1024),
 
     %% SLF LEFT OFF HERE.
     %% When the caller uses small hunks, like 4k via
@@ -185,74 +185,62 @@ bulk_sendsend2(Terms, BinSize, BusyBufSize) ->
     %% default busy size and "+zdbbl 5", and if the 5 case gets
     %% "many many more" monitor messages, then we know we're working.
 
-    {ok, NodeSend} = start_node(bulk_sender, "+zdbbl " ++ integer_to_list(BusyBufSize)),
-    _Send = spawn(NodeSend, erlang, apply, [fun sendersender/4, [self(), Recv, Bin, Terms]]),
+    {ok, NodeSend} = start_node(bulk_sender, "+zdbbl " ++
+                                    integer_to_list(BusyBufSize)),
+    _Send = spawn(NodeSend, erlang, apply,
+                  [fun sendersender/4, [self(), Recv, Bin, Terms]]),
     {Elapsed, {_TermsN, SizeN}, MonitorCount} =
-    receive
-        %% On some platforms (windows), the time taken is 0 so we
-        %% simulate that some little time has passed.
-        {sendersender, {0.0,T,MC}} ->
-            {0.0015, T, MC};
-        {sendersender, BigRes} ->
-            BigRes
-    end,
+        receive
+            %% On some platforms (Windows), the time taken is 0 so we
+            %% simulate that some little time has passed.
+            {sendersender, {0.0,T,MC}} ->
+                {0.0015, T, MC};
+            {sendersender, BigRes} ->
+                BigRes
+        end,
     stop_node(NodeRecv),
     stop_node(NodeSend),
-    {trunc(SizeN/1024/Elapsed+0.5), MonitorCount}.
-
-sender(To, _Bin, 0) ->
-    To ! {done, self()},
-    receive
-        Any ->
-            Any
-    end;
-sender(To, Bin, Left) ->
-    To ! {term, Bin},
-    sender(To, Bin, Left-1).
+    {round(SizeN/1024/Elapsed), MonitorCount}.
 
 %% Sender process to be run on a slave node
 
 sendersender(Parent, To, Bin, Left) ->
     erlang:system_monitor(self(), [busy_dist_port]),
-    [spawn(fun() -> sendersender2(To, Bin, Left, false) end) ||
-     _ <- lists:seq(1,1)],
+    _ = spawn(fun() ->
+                      sendersender_send(To, Bin, Left),
+                      exit(normal)
+              end),
     {USec, {Res, MonitorCount}} =
-    timer:tc(?MODULE, sendersender2, [To, Bin, Left, true]),
+        timer:tc(fun() ->
+                         sendersender_send(To, Bin, Left),
+                         To ! {done, self()},
+                         count_monitors(0)
+                 end),
     Parent ! {sendersender, {USec/1000000, Res, MonitorCount}}.
 
-sendersender2(To, Bin, Left, SendDone) ->
-    sendersender3(To, Bin, Left, SendDone, 0).
+sendersender_send(_To, _Bin, 0) ->
+    ok;
+sendersender_send(To, Bin, Left) ->
+    To ! {term, Bin},
+    sendersender_send(To, Bin, Left-1).
 
-sendersender3(To, _Bin, 0, SendDone, MonitorCount) ->
-    if SendDone ->
-           To ! {done, self()};
-       true ->
-           ok
-    end,
+count_monitors(MonitorCount) ->
     receive
         {monitor, _Pid, _Type, _Info} ->
-            sendersender3(To, _Bin, 0, SendDone, MonitorCount + 1)
+            count_monitors(MonitorCount + 1)
     after 0 ->
-              if SendDone ->
-                     receive
-                         Any when is_tuple(Any), size(Any) == 2 ->
-                             {Any, MonitorCount}
-                     end;
-                 true ->
-                     exit(normal)
-              end
-    end;
-sendersender3(To, Bin, Left, SendDone, MonitorCount) ->
-    To ! {term, Bin},
-    %%timer:sleep(50),
-    sendersender3(To, Bin, Left-1, SendDone, MonitorCount).
+            receive
+                {_,_}=Any ->
+                    {Any,MonitorCount}
+            end
+    end.
 
 %% Receiver process to be run on a slave node.
 
 receiver(Terms, Size) ->
     receive
         {term, Bin} ->
-            receiver(Terms+1, Size+size(Bin));
+            receiver(Terms+1, Size+byte_size(Bin));
         {done, ReplyTo} ->
             ReplyTo ! {Terms, Size}
     end.
diff --git a/erts/emulator/test/evil_SUITE.erl b/erts/emulator/test/evil_SUITE.erl
index 9416ac7a02..fb1954ce37 100644
--- a/erts/emulator/test/evil_SUITE.erl
+++ b/erts/emulator/test/evil_SUITE.erl
@@ -34,7 +34,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 30}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [heap_frag, encode_decode_ext, decode_integer_ext,
diff --git a/erts/emulator/test/exception_SUITE.erl b/erts/emulator/test/exception_SUITE.erl
index 76e3556bc4..ad6d8c890f 100644
--- a/erts/emulator/test/exception_SUITE.erl
+++ b/erts/emulator/test/exception_SUITE.erl
@@ -33,7 +33,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [badmatch, pending_errors, nil_arith, stacktrace,
diff --git a/erts/emulator/test/lttng_SUITE.erl b/erts/emulator/test/lttng_SUITE.erl
index c12f63706a..1c1952f912 100644
--- a/erts/emulator/test/lttng_SUITE.erl
+++ b/erts/emulator/test/lttng_SUITE.erl
@@ -40,7 +40,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [t_lttng_list,
diff --git a/erts/emulator/test/match_spec_SUITE.erl b/erts/emulator/test/match_spec_SUITE.erl
index eb189c2c33..92ddc23592 100644
--- a/erts/emulator/test/match_spec_SUITE.erl
+++ b/erts/emulator/test/match_spec_SUITE.erl
@@ -42,7 +42,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 30}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     case test_server:is_native(match_spec_SUITE) of
diff --git a/erts/emulator/test/nested_SUITE.erl b/erts/emulator/test/nested_SUITE.erl
index 7af2873ce2..5059317172 100644
--- a/erts/emulator/test/nested_SUITE.erl
+++ b/erts/emulator/test/nested_SUITE.erl
@@ -27,7 +27,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [case_in_case, case_in_after, catch_in_catch,
diff --git a/erts/emulator/test/old_scheduler_SUITE.erl b/erts/emulator/test/old_scheduler_SUITE.erl
deleted file mode 100644
index 8515a87df8..0000000000
--- a/erts/emulator/test/old_scheduler_SUITE.erl
+++ /dev/null
@@ -1,384 +0,0 @@
-%%
-%% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 2004-2016. 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(old_scheduler_SUITE).
-
--include_lib("common_test/include/ct.hrl").
-
--export([all/0, suite/0,
-         init_per_testcase/2, end_per_testcase/2]).
--export([equal/1, many_low/1, few_low/1, max/1, high/1]).
-
-suite() ->
-    [{ct_hooks,[ts_install_cth]},
-     {timetrap, {minutes, 11}}].
-
-all() -> 
-    case catch erlang:system_info(modified_timing_level) of
-        Level when is_integer(Level) ->
-            {skipped,
-             "Modified timing (level " ++
-             integer_to_list(Level) ++
-             ") is enabled. Testcases gets messed "
-             "up by modfied timing."};
-        _ -> [equal, many_low, few_low, max, high]
-    end.
-
-
-%%-----------------------------------------------------------------------------------
-%% TEST SUITE DESCRIPTION
-%%
-%% The test case function spawns two controlling processes: Starter and Receiver.
-%% Starter spawns a number of prio A and a number of prio B test processes. Each
-%% test process loops for a number of times, sends a report to the Receiver, then
-%% loops again. For each report, the Receiver increases a counter that corresponds
-%% to the priority of the sender. After a certain amount of time, the Receiver
-%% sends the collected data to the main test process and waits for the test case
-%% to terminate. From this data, it's possible to calculate the average run time
-%% relationship between the prio A and B test processes.
-%%
-%% Note that in order to be able to run tests with high or max prio test processes, 
-%% the main test process and the Receiver needs to run at max prio, or they will
-%% be starved by the test processes. The controlling processes must not wait for
-%% messages from a normal (or low) prio process while max or high prio test processes
-%% are running (which happens e.g. if an io function is called).
-%%-----------------------------------------------------------------------------------
-
-init_per_testcase(_Case, Config) ->
-    %% main test process needs max prio
-    Prio = process_flag(priority, max),
-    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_normal),
-    Prio=proplists:get_value(prio, Config),
-    process_flag(priority, Prio),
-    ok.
-
-ok(Config) when is_list(Config) ->
-    case proplists:get_value(multi_scheduling, Config) of
-        blocked ->
-            {comment,
-             "Multi-scheduling blocked during test. This testcase was not "
-             "written to work with multiple schedulers."};
-        _ -> ok
-    end.
-
-%% Run equal number of low and normal prio processes.
-
-equal(Config) when is_list(Config) ->
-    Self = self(),
-
-    %% specify number of test processes to run
-    Normal = {normal,500},
-    Low    = {low,500},
-
-    %% specify time of test (in seconds)
-    Time = 30,
-
-    %% start controllers
-    Receiver = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
-    Starter =
-    spawn(fun() -> starter(Normal, Low, Receiver) end),
-
-    %% receive test data from Receiver
-    {NRs,NAvg,LRs,LAvg,Ratio} = 
-    receive
-        {Receiver,Res} -> Res
-    end,
-
-    %% stop controllers and test processes
-    exit(Starter, kill),
-    exit(Receiver, kill),
-
-    io:format("Reports: ~w normal (~w/proc), ~w low (~w/proc). Ratio: ~w~n", 
-              [NRs,NAvg,LRs,LAvg,Ratio]),
-
-    %% runtime ratio between normal and low should be ~8
-    if Ratio < 7.5 ; Ratio > 8.5 ->	
-           ct:fail({bad_ratio,Ratio});
-       true ->
-           ok(Config)
-    end.
-
-
-%% Run many low and few normal prio processes.
-
-many_low(Config) when is_list(Config) ->
-    Self = self(),
-    Normal = {normal,1},
-    Low    = {low,1000},
-
-    %% specify time of test (in seconds)
-    Time = 30,
-
-    Receiver = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
-    Starter =
-    spawn(fun() -> starter(Normal, Low, Receiver) end),
-    {NRs,NAvg,LRs,LAvg,Ratio} = 
-    receive
-        {Receiver,Res} -> Res
-    end,
-    exit(Starter, kill),
-    exit(Receiver, kill),
-    io:format("Reports: ~w normal (~w/proc), ~w low (~w/proc). Ratio: ~w~n", 
-              [NRs,NAvg,LRs,LAvg,Ratio]),
-    if Ratio < 7.5 ; Ratio > 8.5 ->
-           ct:fail({bad_ratio,Ratio});
-       true ->
-           ok(Config)
-    end.
-
-
-%% Run few low and many normal prio processes.
-
-few_low(Config) when is_list(Config) ->
-    Self = self(),
-    Normal = {normal,1000},
-    Low    = {low,1},
-
-    %% specify time of test (in seconds)
-    Time = 30,
-
-    Receiver = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
-    Starter =
-    spawn(fun() -> starter(Normal, Low, Receiver) end),
-    {NRs,NAvg,LRs,LAvg,Ratio} = 
-    receive
-        {Receiver,Res} -> Res
-    end,
-    exit(Starter, kill),
-    exit(Receiver, kill),
-    io:format("Reports: ~w normal (~w/proc), ~w low (~w/proc). Ratio: ~w~n", 
-              [NRs,NAvg,LRs,LAvg,Ratio]),
-    if Ratio < 7.0 ; Ratio > 8.5 ->
-           ct:fail({bad_ratio,Ratio});
-       true ->
-           ok(Config)
-    end.
-
-
-%% Run max prio processes and verify they get at least as much 
-%% runtime as high, normal and low.
-
-max(Config) when is_list(Config) ->
-    max = process_flag(priority, max),		% should already be max (init_per_tc)
-    Self = self(),
-    Max    = {max,2},
-    High   = {high,2},
-    Normal = {normal,100},
-    Low    = {low,100},
-
-    %% specify time of test (in seconds)
-    Time = 30,
-
-    Receiver1 = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, High) end),
-    Starter1 =
-    spawn(fun() -> starter(Max, High, Receiver1) end),
-    {M1Rs,M1Avg,HRs,HAvg,Ratio1} = 
-    receive
-        {Receiver1,Res1} -> Res1
-    end,
-    exit(Starter1, kill),
-    exit(Receiver1, kill),
-    io:format("Reports: ~w max (~w/proc), ~w high (~w/proc). Ratio: ~w~n", 
-              [M1Rs,M1Avg,HRs,HAvg,Ratio1]),
-    if Ratio1 < 1.0 ->
-           ct:fail({bad_ratio,Ratio1});
-       true ->
-           ok(Config)
-    end,
-
-    Receiver2 = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, Normal) end),
-    Starter2 =
-    spawn(fun() -> starter(Max, Normal, Receiver2) end),
-    {M2Rs,M2Avg,NRs,NAvg,Ratio2} = 
-    receive
-        {Receiver2,Res2} -> Res2
-    end,
-    exit(Starter2, kill),
-    exit(Receiver2, kill),
-    io:format("Reports: ~w max (~w/proc), ~w normal (~w/proc). Ratio: ~w~n", 
-              [M2Rs,M2Avg,NRs,NAvg,Ratio2]),
-    if Ratio2 < 1.0 ->
-           ct:fail({bad_ratio,Ratio2});
-       true ->
-           ok
-    end,
-
-    Receiver3 = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, Low) end),
-    Starter3 =
-    spawn(fun() -> starter(Max, Low, Receiver3) end),
-    {M3Rs,M3Avg,LRs,LAvg,Ratio3} = 
-    receive
-        {Receiver3,Res3} -> Res3
-    end,
-    exit(Starter3, kill),
-    exit(Receiver3, kill),
-    io:format("Reports: ~w max (~w/proc), ~w low (~w/proc). Ratio: ~w~n", 
-              [M3Rs,M3Avg,LRs,LAvg,Ratio3]),
-    if Ratio3 < 1.0 ->
-           ct:fail({bad_ratio,Ratio3});
-       true ->
-           ok(Config)
-    end.
-
-
-%% Run high prio processes and verify they get at least as much 
-%% runtime as normal and low.
-
-high(Config) when is_list(Config) ->
-    max = process_flag(priority, max),		% should already be max (init_per_tc)
-    Self = self(),
-    High   = {high,2},
-    Normal = {normal,100},
-    Low    = {low,100},
-
-    %% specify time of test (in seconds)
-    Time = 30,
-
-    Receiver1 = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, High, Normal) end),
-    Starter1 =
-    spawn(fun() -> starter(High, Normal, Receiver1) end),
-    {H1Rs,H1Avg,NRs,NAvg,Ratio1} = 
-    receive
-        {Receiver1,Res1} -> Res1
-    end,
-    exit(Starter1, kill),
-    exit(Receiver1, kill),
-    io:format("Reports: ~w high (~w/proc), ~w normal (~w/proc). Ratio: ~w~n", 
-              [H1Rs,H1Avg,NRs,NAvg,Ratio1]),
-    if Ratio1 < 1.0 ->
-           ct:fail({bad_ratio,Ratio1});
-       true ->
-           ok
-    end,
-
-    Receiver2 = 
-    spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, High, Low) end),
-    Starter2 =
-    spawn(fun() -> starter(High, Low, Receiver2) end),
-    {H2Rs,H2Avg,LRs,LAvg,Ratio2} = 
-    receive
-        {Receiver2,Res2} -> Res2
-    end,
-    exit(Starter2, kill),
-    exit(Receiver2, kill),
-    io:format("Reports: ~w high (~w/proc), ~w low (~w/proc). Ratio: ~w~n", 
-              [H2Rs,H2Avg,LRs,LAvg,Ratio2]),
-    if Ratio2 < 1.0 ->
-           ct:fail({bad_ratio,Ratio2});
-       true ->
-           ok(Config)
-    end.
-
-
-%%-----------------------------------------------------------------------------------
-%% Controller processes and help functions
-%%-----------------------------------------------------------------------------------
-
-receiver(T0, TimeSec, Main, {P1,P1N}, {P2,P2N}) ->
-    %% prio should be max so that mailbox doesn't overflow
-    process_flag(priority, max),
-    receiver(T0, TimeSec*1000, Main, P1,P1N,0, P2,P2N,0, 100000).
-
-%% uncomment lines below to get life sign (debug)
-receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, 0) ->
-    %    T = erlang:convert_time_unit(erlang:monotonic_time() - T0, native, millisecond),
-    %    erlang:display({round(T/1000),P1Rs,P2Rs}),
-    receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, 100000);
-
-receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, C) ->
-    Remain = Time - erlang:convert_time_unit(erlang:monotonic_time() - T0,
-                                             native, millisecond), % test time remaining
-    Remain1 = if Remain < 0 ->
-                     0;
-                 true ->
-                     Remain
-              end,
-    {P1Rs1,P2Rs1} = 
-    receive
-        {_Pid,P1} ->			% report from a P1 process
-            {P1Rs+1,P2Rs};
-        {_Pid,P2} ->			% report from a P2 process
-            {P1Rs,P2Rs+1}
-    after Remain1 ->
-              {P1Rs,P2Rs}
-    end,
-    if Remain > 0 ->				% keep going
-           receiver(T0, Time, Main, P1,P1N,P1Rs1, P2,P2N,P2Rs1, C-1);
-       true ->					% finish
-           %% calculate results and send to main test process
-           P1Avg = P1Rs1/P1N,
-           P2Avg = P2Rs1/P2N,
-           Ratio = if P2Avg < 1.0 -> P1Avg;
-                      true -> P1Avg/P2Avg
-                   end,
-           Main ! {self(),{P1Rs1,round(P1Avg),P2Rs1,round(P2Avg),Ratio}},
-           flush_loop()
-    end.
-
-starter({P1,P1N}, {P2,P2N}, Receiver) ->
-    %% start N1 processes with prio P1
-    start_p(P1, P1N, Receiver),
-    %% start N2 processes with prio P2
-    start_p(P2, P2N, Receiver),
-    erlang:display({started,P1N+P2N}),
-    flush_loop().
-
-start_p(_, 0, _) ->
-    ok;
-start_p(Prio, N, Receiver) ->
-    spawn_link(fun() -> p(Prio, Receiver) end),
-    start_p(Prio, N-1, Receiver).
-
-p(Prio, Receiver) ->
-    %% set process priority
-    process_flag(priority, Prio),
-    p_loop(0, Prio, Receiver).
-
-p_loop(100, Prio, Receiver) ->
-    receive after 0 -> ok end,
-    %% if Receiver gone, we're done
-    case is_process_alive(Receiver) of
-        false -> exit(bye);
-        true -> ok
-    end,
-    %% send report
-    Receiver ! {self(),Prio},
-    p_loop(0, Prio, Receiver);
-
-p_loop(N, Prio, Receiver) ->
-    p_loop(N+1, Prio, Receiver).
-
-
-flush_loop() ->
-    receive _ ->
-                ok
-    end,
-    flush_loop().
diff --git a/erts/emulator/test/port_SUITE.erl b/erts/emulator/test/port_SUITE.erl
index 94ee9851dd..fccbaf13ee 100644
--- a/erts/emulator/test/port_SUITE.erl
+++ b/erts/emulator/test/port_SUITE.erl
@@ -153,7 +153,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 10}}].
+     {timetrap, {minutes, 1}}].
 
 all() ->
     [otp_6224, {group, stream}, basic_ping, slow_writes,
diff --git a/erts/emulator/test/port_trace_SUITE.erl b/erts/emulator/test/port_trace_SUITE.erl
index 03efdc15db..bfc3c8cb51 100644
--- a/erts/emulator/test/port_trace_SUITE.erl
+++ b/erts/emulator/test/port_trace_SUITE.erl
@@ -52,7 +52,7 @@
 -define(ECHO_DRV_REMOTE_SEND_TERM, 15).
 
 suite() -> [{ct_hooks,[ts_install_cth]},
-            {timetrap, {seconds, 30}}].
+            {timetrap, {minutes, 2}}].
 
 all() ->
     [port_specs, ports, open_close,
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index e14185e881..4204d12eb3 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -134,6 +134,11 @@ init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
     [{testcase, Func}|Config].
 
 end_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
+    %% Restore max_heap_size to default value.
+    erlang:system_flag(max_heap_size,
+                       #{size => 0,
+                         kill => true,
+                         error_logger => true}),
     ok.
 
 fun_spawn(Fun) ->
@@ -1024,36 +1029,48 @@ bump_big(Prev, Limit) ->
 %% Priority 'low' should be mixed with 'normal' using a factor of
 %% about 8. (OTP-2644)
 low_prio(Config) when is_list(Config) ->
-    case erlang:system_info(schedulers_online) of
-	1 ->
-	    ok = low_prio_test(Config);
-	_ -> 
-	    erlang:system_flag(multi_scheduling, block_normal),
-	    ok = low_prio_test(Config),
-	    erlang:system_flag(multi_scheduling, unblock_normal),
-	    {comment,
-		   "Test not written for SMP runtime system. "
-		   "Multi scheduling blocked during test."}
-    end.
+    erlang:system_flag(multi_scheduling, block_normal),
+    Prop = low_prio_test(Config),
+    erlang:system_flag(multi_scheduling, unblock_normal),
+    Str = lists:flatten(io_lib:format("Low/high proportion is ~.3f",
+                                      [Prop])),
+    {comment,Str}.
 
 low_prio_test(Config) when is_list(Config) ->
     process_flag(trap_exit, true),
-    S = spawn_link(?MODULE, prio_server, [0, 0]),
+
+    %% Spawn the server running with high priority. The server must
+    %% not run at normal priority as that would skew the results for
+    %% two reasons:
+    %%
+    %% 1. There would be one more normal-priority processes than
+    %% low-priority processes.
+    %%
+    %% 2. The receive queue would grow faster than the server process
+    %% could process it. That would in turn trigger the reduction
+    %% punishment for the clients.
+    S = spawn_opt(?MODULE, prio_server, [0, 0], [link,{priority,high}]),
+
+    %% Spawn the clients and let them run for a while.
     PCs = spawn_prio_clients(S, erlang:system_info(schedulers_online)),
-    ct:sleep({seconds,3}),
+    ct:sleep({seconds,2}),
     lists:foreach(fun (P) -> exit(P, kill) end, PCs),
+
+    %% Stop the server and retrieve the result.
     S ! exit,
-    receive {'EXIT', S, {A, B}} -> check_prio(A, B) end,
-    ok.
+    receive
+        {'EXIT', S, {A, B}} ->
+            check_prio(A, B)
+    end.
 
 check_prio(A, B) ->
     Prop = A/B,
     ok = io:format("Low=~p, High=~p, Prop=~p\n", [A, B, Prop]),
 
-    %% It isn't 1/8, it's more like 0.3, but let's check that
-    %% the low-prio processes get some little chance to run at all.
-    true = (Prop < 1.0),
-    true = (Prop > 1/32).
+    %% Prop is expected to be appr. 1/8. Allow a reasonable margin.
+    true = Prop < 1/4,
+    true = Prop > 1/16,
+    Prop.
 
 prio_server(A, B) ->
     receive
@@ -2057,6 +2074,7 @@ max_heap_size_test(Option, Size, Kill, ErrorLogger) ->
     end,
     if ErrorLogger ->
             receive
+                %% There must be at least one error message.
                 {error, _, {emulator, _, [Pid|_]}} ->
                     ok
             end;
@@ -2069,22 +2087,33 @@ max_heap_size_test(Option, Size, Kill, ErrorLogger) ->
                 {'DOWN', Ref, process, Pid, die} ->
                     ok
             end,
-            flush();
+            %% If the process was not killed, the limit may have
+            %% been reached more than once and there may be
+            %% more {error, ...} messages left.
+            receive_error_messages(Pid);
        true ->
             ok
     end,
+
+    %% Make sure that there are no unexpected messages.
+    receive_unexpected().
+
+receive_error_messages(Pid) ->
     receive
-        M ->
-            ct:fail({unexpected_message, M})
-    after 10 ->
+        {error, _, {emulator, _, [Pid|_]}} ->
+            receive_error_messages(Pid)
+    after 1000 ->
             ok
     end.
 
-flush() ->
+receive_unexpected() ->
     receive
-        _M ->
-            flush()
-    after 1000 ->
+        {info_report, _, _} ->
+            %% May be an alarm message from os_mon. Ignore.
+            receive_unexpected();
+        M ->
+            ct:fail({unexpected_message, M})
+    after 10 ->
             ok
     end.
 
diff --git a/erts/emulator/test/receive_SUITE.erl b/erts/emulator/test/receive_SUITE.erl
index 83653a7a36..c7d5a3f5a0 100644
--- a/erts/emulator/test/receive_SUITE.erl
+++ b/erts/emulator/test/receive_SUITE.erl
@@ -39,25 +39,43 @@ groups() ->
 
 call_with_huge_message_queue(Config) when is_list(Config) ->
     Pid = spawn_link(fun echo_loop/0),
-
-    {Time,ok} = tc(fun() -> calls(10, Pid) end),
-
-    [self() ! {msg,N} || N <- lists:seq(1, 500000)],
+    _WarmUpTime = time_calls(Pid),
+    Time = time_calls(Pid),
+    _ = [self() ! {msg,N} || N <- lists:seq(1, 500000)],
+    io:format("Time for empty message queue: ~p", [Time]),
     erlang:garbage_collect(),
-    {NewTime1,ok} = tc(fun() -> calls(10, Pid) end),
-    {NewTime2,ok} = tc(fun() -> calls(10, Pid) end),
+    call_with_huge_message_queue_1(Pid, Time, 5).
+
+call_with_huge_message_queue_1(_Pid, _Time, 0) ->
+    ct:fail(bad_ratio);
+call_with_huge_message_queue_1(Pid, Time, NumTries) ->
+    HugeTime = time_calls(Pid),
+    io:format("Time for huge message queue: ~p", [HugeTime]),
+
+    case (HugeTime+1) / (Time+1) of
+        Q when Q < 10 ->
+            ok;
+        Q ->
+            io:format("Too high ratio: ~p\n", [Q]),
+            call_with_huge_message_queue_1(Pid, Time, NumTries-1)
+    end.
 
-    io:format("Time for empty message queue: ~p", [Time]),
-    io:format("Time1 for huge message queue: ~p", [NewTime1]),
-    io:format("Time2 for huge message queue: ~p", [NewTime2]),
-
-    case hd(lists:sort([(NewTime1+1) / (Time+1), (NewTime2+1) / (Time+1)])) of
-	Q when Q < 10 ->
-	    ok;
-	Q ->
-	    ct:fail("Best Q = ~p", [Q])
-    end,
-    ok.
+%% Time a number calls. Try to avoid returning a zero time.
+time_calls(Pid) ->
+    time_calls(Pid, 10).
+
+time_calls(_Pid, 0) ->
+    0;
+time_calls(Pid, NumTries) ->
+    case timer:tc(fun() -> calls(Pid) end) of
+        {0,ok} ->
+            time_calls(Pid, NumTries-1);
+        {Time,ok} ->
+            Time
+    end.
+
+calls(Pid) ->
+    calls(100, Pid).
 
 calls(0, _) -> ok;
 calls(N, Pid) ->
@@ -108,6 +126,3 @@ echo_loop() ->
 	    Pid ! {Ref,Msg},
 	    echo_loop()
     end.
-
-tc(Fun) ->
-    timer:tc(erlang, apply, [Fun,[]]).
diff --git a/erts/emulator/test/timer_bif_SUITE.erl b/erts/emulator/test/timer_bif_SUITE.erl
index 7cbd93a0f3..a977eb41c4 100644
--- a/erts/emulator/test/timer_bif_SUITE.erl
+++ b/erts/emulator/test/timer_bif_SUITE.erl
@@ -488,24 +488,40 @@ registered_process(Config) when is_list(Config) ->
 
 same_time_yielding(Config) when is_list(Config) ->
     Mem = mem(),
+    Ref = make_ref(),
     SchdlrsOnln = erlang:system_info(schedulers_online),
     Tmo = erlang:monotonic_time(millisecond) + 3000,
     Tmrs = lists:map(fun (I) ->
                              process_flag(scheduler, (I rem SchdlrsOnln) + 1),
-                             erlang:start_timer(Tmo, self(), hej, [{abs, true}])
+                             erlang:start_timer(Tmo, self(), Ref, [{abs, true}])
                      end,
                      lists:seq(1, (?TIMEOUT_YIELD_LIMIT*3+1)*SchdlrsOnln)),
     true = mem_larger_than(Mem),
-    lists:foreach(fun (Tmr) -> receive {timeout, Tmr, hej} -> ok end end, Tmrs),
+    receive_all_timeouts(length(Tmrs), Ref),
     Done = erlang:monotonic_time(millisecond),
     true = Done >= Tmo,
+    MsAfterTmo = Done - Tmo,
+    io:format("Done ~p ms after Tmo\n", [MsAfterTmo]),
     case erlang:system_info(build_type) of
-        opt -> true = Done < Tmo + 200;
-        _ -> true = Done < Tmo + 1000
+        opt ->
+            true = MsAfterTmo < 200;
+        _ ->
+            true = MsAfterTmo < 1000
     end,
     Mem = mem(),
     ok.
 
+%% Read out all timeouts in receive queue order. This is efficient
+%% even if there are very many messages.
+
+receive_all_timeouts(0, _Ref) ->
+    ok;
+receive_all_timeouts(N, Ref) ->
+    receive
+        {timeout, _Tmr, Ref} ->
+            receive_all_timeouts(N-1, Ref)
+    end.
+
 same_time_yielding_with_cancel(Config) when is_list(Config) ->
     same_time_yielding_with_cancel_test(false, false).
 
diff --git a/erts/emulator/test/trace_SUITE.erl b/erts/emulator/test/trace_SUITE.erl
index 643c2e0472..bd0ea22de9 100644
--- a/erts/emulator/test/trace_SUITE.erl
+++ b/erts/emulator/test/trace_SUITE.erl
@@ -46,7 +46,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 5}}].
+     {timetrap, {minutes, 1}}].
 
 all() -> 
     [cpu_timestamp, receive_trace, link_receive_call_correlation,
@@ -184,10 +184,10 @@ receive_trace(Config) when is_list(Config) ->
     {'EXIT', Intruder, {badarg, _}} = receive_first(),
 
     %% Untrace the process; we should not receive anything.
-    ?line 1 = erlang:trace(Receiver, false, ['receive']),
-    ?line Receiver ! {hello, there},
-    ?line Receiver ! any_garbage,
-    ?line receive_nothing(),
+    1 = erlang:trace(Receiver, false, ['receive']),
+    Receiver ! {hello, there},
+    Receiver ! any_garbage,
+    receive_nothing(),
 
     %% Verify restrictions in matchspec for 'receive'
     F3 = fun (Pat) -> {'EXIT', {badarg,_}} = (catch erlang:trace_pattern('receive', Pat, [])) end,
diff --git a/erts/emulator/test/trace_port_SUITE.erl b/erts/emulator/test/trace_port_SUITE.erl
index e4db368ea1..5eb27a7b68 100644
--- a/erts/emulator/test/trace_port_SUITE.erl
+++ b/erts/emulator/test/trace_port_SUITE.erl
@@ -37,7 +37,7 @@
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
-     {timetrap, {seconds, 30}}].
+     {timetrap, {minutes, 2}}].
 
 all() ->
     [call_trace, return_trace, send, receive_trace,