erts: Add microstate accounting

Microstate accounting is a way to track which state the
different threads within ERTS are in. The main usage area
is to pin point performance bottlenecks by checking which
states the threads are in and then from there figuring out
why and where to optimize.

Since checking whether microstate accounting is on or off is
relatively expensive if done in a short loop only a few of the
states are enabled by default and more states can be enabled
through configure.

I've done some benchmarking and the overhead with it turned off
is not noticible and with it on it is a fraction of a percent.
If you enable the extra states, depending on the benchmark,
the ovehead when turned off is about 1% and when turned on
somewhere inbetween 5-15%.

OTP-12345

1 files changed, 132 insertions, 0 deletions

diff --git a/lib/runtime_tools/test/msacc_SUITE.erl b/lib/runtime_tools/test/msacc_SUITE.erl
new file mode 100644
index 0000000000..145a6d07fb
--- /dev/null
+++ b/lib/runtime_tools/test/msacc_SUITE.erl
@@ -0,0 +1,132 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2014-2015. 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(msacc_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+
+%% Test server callbacks
+-export([suite/0, all/0]).
+
+%% Test cases
+-export([
+	%% API-test
+	api_file/1,
+        api_start_stop/1,
+	api_timer/1,
+        api_print/1
+    ]).
+
+%%--------------------------------------------------------------------
+%% COMMON TEST CALLBACK FUNCTIONS
+%%--------------------------------------------------------------------
+all() ->
+    [
+     api_start_stop,
+     api_file,
+     api_timer,
+     api_print
+    ].
+
+suite() -> [
+	{timetrap,{minutes,1}},
+	{ct_hooks,[ts_install_cth]}
+    ].
+
+%%--------------------------------------------------------------------
+%% TEST CASES
+%%--------------------------------------------------------------------
+
+api_timer(_Config) ->
+
+    %% Run msacc for about 100ms
+    msacc:start(100),
+
+    %% Verify that scheduler 1 executed+slept for about 100ms
+    [Sched1] = [S || S = #{ type := scheduler, id := 1 } <- msacc:stats()],
+
+    #{ counters := Cnt } = Sched1,
+
+    %% Time should be in us
+    Time = maps:fold(fun(_,V,Acc) -> V + Acc end, 0, Cnt),
+
+    if Time < 120000 andalso Time > 80000 -> ok;
+       true -> ct:fail({inaccurate_time, Time, msacc:stats()})
+    end.
+
+%% We just do a basic check that none of the apis crash
+api_start_stop(_Config) ->
+    msacc:start(),
+    timer:sleep(100),
+    msacc:stop(),
+    Runtime = msacc:stats(system_runtime, msacc:stats()),
+    Realtime = msacc:stats(system_realtime, msacc:stats()),
+    true = Runtime < Realtime,
+
+    RuntimeCnt = msacc:stats(runtime, msacc:stats()),
+    RealtimeCnt = msacc:stats(realtime, msacc:stats()),
+    TypeCnt = msacc:stats(type, msacc:stats()),
+
+    %% These should be very similar
+    RuntimeTypeCnt = msacc:stats(type, RuntimeCnt),
+    TypeRuntimeCnt = msacc:stats(runtime, TypeCnt),
+    lists:map(fun({#{ system := T1 },#{ system := T2}}) ->
+                      if T1-0.5 < T2 orelse T1+0.5 > T2 -> ok;
+                         true -> ct:fail({inaccurate_stats, RuntimeTypeCnt,
+                                          TypeRuntimeCnt})
+                      end
+              end, lists:zip(RuntimeTypeCnt, TypeRuntimeCnt)),
+
+    %% These should be very similar
+    RealtimeTypeCnt = msacc:stats(type, RealtimeCnt),
+    TypeRealtimeCnt = msacc:stats(realtime, TypeCnt),
+    lists:map(fun({#{ system := T1 },#{ system := T2}}) ->
+                      if T1-0.5 < T2 orelse T1+0.5 > T2 -> ok;
+                         true -> ct:fail({inaccurate_stats, RealtimeTypeCnt,
+                                          TypeRealtimeCnt})
+                      end
+              end,lists:zip(RealtimeTypeCnt, TypeRealtimeCnt)),
+
+    msacc:reset().
+
+api_file(Config) ->
+    PrivDir = proplists:get_value(priv_dir, Config),
+    File = filename:join(PrivDir, "msacc.stats"),
+    Stats = msacc:stats(),
+    ok = msacc:to_file(File),
+    Stats = msacc:from_file(File),
+
+    PrintFile = filename:join(PrivDir, "msacc.txt"),
+    msacc:print(PrintFile, Stats, #{}).
+
+%% We just check that it is possible to print in a couple of different ways
+api_print(_Config) ->
+    msacc:start(100),
+    io:format("msacc:print(msacc:stats()).~n"),
+    msacc:print(msacc:stats()),
+    io:format("msacc:print(msacc:stats(),#{ system => true }).~n"),
+    msacc:print(msacc:stats(), #{ system => true }),
+    io:format("msacc:print(msacc:stats(runtime,msacc:stats())).~n"),
+    msacc:print(msacc:stats(runtime, msacc:stats())),
+    io:format("msacc:print(msacc:stats(type,msacc:stats())).~n"),
+    msacc:print(msacc:stats(type, msacc:stats())),
+    io:format("msacc:print(msacc:stats(realtime,msacc:stats())).~n"),
+    msacc:print(msacc:stats(realtime, msacc:stats())),
+    io:format("msacc:stats(type,msacc:stats(runtime,msacc:stats())).~n"),
+    msacc:print(msacc:stats(type, msacc:stats(runtime, msacc:stats()))).