Scheduler wall time support for dirty schedulers

1 files changed, 118 insertions, 13 deletions

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.