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authorSverker Eriksson <[email protected]>2018-01-11 20:52:27 +0100
committerSverker Eriksson <[email protected]>2018-01-29 18:24:23 +0100
commit0359cdc8552ad056e976a8c097624b4305ef6755 (patch)
treef7dc7c928559e6c2d39607529b1d2b9b81dd9f4e /lib/runtime_tools/src
parent919ef5de2858e606d4a9be3e0e995b0802c76e33 (diff)
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runtime_tools: Add scheduler module
Diffstat (limited to 'lib/runtime_tools/src')
-rw-r--r--lib/runtime_tools/src/Makefile1
-rw-r--r--lib/runtime_tools/src/runtime_tools.app.src1
-rw-r--r--lib/runtime_tools/src/scheduler.erl152
3 files changed, 154 insertions, 0 deletions
diff --git a/lib/runtime_tools/src/Makefile b/lib/runtime_tools/src/Makefile
index 5a99c6e240..6faa9c2e35 100644
--- a/lib/runtime_tools/src/Makefile
+++ b/lib/runtime_tools/src/Makefile
@@ -45,6 +45,7 @@ MODULES= \
system_information \
observer_backend \
ttb_autostart\
+ scheduler\
msacc
HRL_FILES= ../include/observer_backend.hrl
diff --git a/lib/runtime_tools/src/runtime_tools.app.src b/lib/runtime_tools/src/runtime_tools.app.src
index 449532e5c4..09a9b447c2 100644
--- a/lib/runtime_tools/src/runtime_tools.app.src
+++ b/lib/runtime_tools/src/runtime_tools.app.src
@@ -23,6 +23,7 @@
{modules, [appmon_info, dbg,observer_backend,runtime_tools,
runtime_tools_sup,erts_alloc_config,
ttb_autostart,dyntrace,system_information,
+ scheduler,
msacc]},
{registered, [runtime_tools_sup]},
{applications, [kernel, stdlib]},
diff --git a/lib/runtime_tools/src/scheduler.erl b/lib/runtime_tools/src/scheduler.erl
new file mode 100644
index 0000000000..c896b671ac
--- /dev/null
+++ b/lib/runtime_tools/src/scheduler.erl
@@ -0,0 +1,152 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018. 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%
+%%
+
+%% @doc Utility functions for easier measurement of scheduler utilization
+%% using erlang:statistics(scheduler_wall_time).
+
+-module(scheduler).
+
+-export([sample/0,
+ sample_all/0,
+ utilization/1,
+ utilization/2]).
+
+-export_type([sched_sample/0]).
+
+
+-opaque sched_sample() ::
+ {scheduler_wall_time | scheduler_wall_time_all,
+ [{sched_type(), sched_id(), ActiveTime::integer(), TotalTime::integer()}]}.
+
+-type sched_type() :: normal | cpu | io.
+
+-type sched_id() :: integer().
+
+-spec sample() -> sched_sample().
+sample() ->
+ sample(scheduler_wall_time).
+
+-spec sample_all() -> sched_sample().
+sample_all() ->
+ sample(scheduler_wall_time_all).
+
+sample(Stats) ->
+ case erlang:statistics(Stats) of
+ undefined ->
+ erlang:system_flag(scheduler_wall_time, true),
+ sample(Stats);
+
+ List ->
+ Sorted = lists:sort(List),
+ Tagged = lists:map(fun({I, A, T}) -> {sched_tag(I), I, A, T} end,
+ Sorted),
+ {Stats, Tagged}
+ end.
+
+-type sched_util_result() ::
+ [{sched_type(), sched_id(), float(), string()} |
+ {total, float(), string()} |
+ {weighted, float(), string()}].
+
+-spec utilization(Seconds) -> sched_util_result() when
+ Seconds :: pos_integer();
+ (Sample) -> sched_util_result() when
+ Sample :: sched_sample().
+utilization(Seconds) when is_integer(Seconds), Seconds > 0 ->
+ OldFlag = erlang:system_flag(scheduler_wall_time, true),
+ T0 = sample(),
+ receive after Seconds*1000 -> ok end,
+ T1 = sample(),
+ case OldFlag of
+ false ->
+ erlang:system_flag(scheduler_wall_time, OldFlag);
+ true ->
+ ok
+ end,
+ utilization(T0,T1);
+
+utilization({Stats, _}=T0) when Stats =:= scheduler_wall_time;
+ Stats =:= scheduler_wall_time_all ->
+ utilization(T0, sample(Stats)).
+
+-spec utilization(Sample1, Sample2) -> sched_util_result() when
+ Sample1 :: sched_sample(),
+ Sample2 :: sched_sample().
+utilization({Stats, Ts0}, {Stats, Ts1}) ->
+ Diffs = lists:map(fun({{Tag, I, A0, T0}, {Tag, I, A1, T1}}) ->
+ {Tag, I, (A1 - A0), (T1 - T0)}
+ end,
+ lists:zip(Ts0,Ts1)),
+
+ {Lst0, {A, T, N}} = lists:foldl(fun({Tag, I, Adiff, Tdiff}, {Lst, Acc}) ->
+ R = safe_div(Adiff, Tdiff),
+ {[{Tag, I, R, percent(R)} | Lst],
+ acc(Tag, Adiff, Tdiff, Acc)}
+ end,
+ {[], {0, 0, 0}},
+ Diffs),
+
+ Total = safe_div(A, T),
+ Lst1 = lists:reverse(Lst0),
+ Lst2 = case erlang:system_info(logical_processors_available) of
+ unknown -> Lst1;
+ LPA ->
+ Weighted = Total * (N / LPA),
+ [{weighted, Weighted, percent(Weighted)} | Lst1]
+ end,
+ [{total, Total, percent(Total)} | Lst2];
+
+utilization({scheduler_wall_time, _}=T0,
+ {scheduler_wall_time_all, Ts1}) ->
+ utilization(T0, {scheduler_wall_time, remove_io(Ts1)});
+
+utilization({scheduler_wall_time_all, Ts0},
+ {scheduler_wall_time, _}=T1) ->
+ utilization({scheduler_wall_time, remove_io(Ts0)}, T1).
+
+%% Do not include dirty-io in totals
+acc(io, _, _, Acc) ->
+ Acc;
+acc(Tag, Adiff, Tdiff, {Asum, Tsum, N}) when Tag =:= normal; Tag =:= cpu ->
+ {Adiff+Asum, Tdiff+Tsum, N+1}.
+
+
+remove_io(Ts) ->
+ lists:filter(fun({io,_,_,_}) -> false;
+ (_) -> true end,
+ Ts).
+
+safe_div(A, B) ->
+ if B == 0.0 -> 0.0;
+ true -> A / B
+ end.
+
+sched_tag(Nr) ->
+ Normal = erlang:system_info(schedulers),
+ Cpu = Normal + erlang:system_info(dirty_cpu_schedulers),
+ case Nr of
+ _ when Nr =< Normal -> normal;
+ _ when Nr =< Cpu -> cpu;
+ _ -> io
+ end.
+
+
+percent(F) ->
+ float_to_list(F*100, [{decimals,1}]) ++ [$%].