diff options
Diffstat (limited to 'lib/runtime_tools/src')
| -rw-r--r-- | lib/runtime_tools/src/Makefile | 1 | ||||
| -rw-r--r-- | lib/runtime_tools/src/runtime_tools.app.src | 1 | ||||
| -rw-r--r-- | lib/runtime_tools/src/scheduler.erl | 152 |
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}]) ++ [$%]. |