Merge branch 'siri/etop/cpu-per-interval/OTP-14090' into maint

* siri/etop/cpu-per-interval/OTP-14090:
  [etop] Show CPU utilization for last interval only

4 files changed, 38 insertions, 25 deletions

diff --git a/lib/observer/src/etop.erl b/lib/observer/src/etop.erl
index fcb900960b..925f4456bb 100644
--- a/lib/observer/src/etop.erl
+++ b/lib/observer/src/etop.erl
@@ -23,7 +23,7 @@
 -export([start/0, start/1, config/2, stop/0, dump/1, help/0]).
 %% Internal
 -export([update/1]).
--export([loadinfo/1, meminfo/2, getopt/2]).
+-export([loadinfo/2, meminfo/2, getopt/2]).
 
 -include("etop.hrl").
 -include("etop_defs.hrl").
@@ -319,18 +319,18 @@ output(graphical) -> exit({deprecated, "Use observer instead"});
 output(text) -> etop_txt.
 
 
-loadinfo(SysI) ->
+loadinfo(SysI,Prev) ->
     #etop_info{n_procs = Procs, 
 	       run_queue = RQ, 
 	       now = Now,
 	       wall_clock = WC,
 	       runtime = RT} = SysI,
-    Cpu = calculate_cpu_utilization(WC,RT),
+    Cpu = calculate_cpu_utilization(WC,RT,Prev#etop_info.runtime),
     Clock = io_lib:format("~2.2.0w:~2.2.0w:~2.2.0w",
 			 tuple_to_list(element(2,calendar:now_to_datetime(Now)))),
     {Cpu,Procs,RQ,Clock}.
 
-calculate_cpu_utilization({_,WC},{_,RT}) ->
+calculate_cpu_utilization({_,WC},{_,RT},_) ->
     %% Old version of observer_backend, using statistics(wall_clock)
     %% and statistics(runtime)
     case {WC,RT} of
@@ -341,15 +341,23 @@ calculate_cpu_utilization({_,WC},{_,RT}) ->
 	_ ->
 	    round(100*RT/WC)
     end;
-calculate_cpu_utilization(_,undefined) ->
+calculate_cpu_utilization(_,undefined,_) ->
     %% First time collecting - no cpu utilization has been measured
     %% since scheduler_wall_time flag is not yet on
     0;
-calculate_cpu_utilization(_,RTInfo) ->
+calculate_cpu_utilization(WC,RTInfo,undefined) ->
+    %% Second time collecting - RTInfo shows scheduler_wall_time since
+    %% flag was set to true. Faking previous values by setting
+    %% everything to zero.
+    ZeroRT = [{Id,0,0} || {Id,_,_} <- RTInfo],
+    calculate_cpu_utilization(WC,RTInfo,ZeroRT);
+calculate_cpu_utilization(_,RTInfo,PrevRTInfo) ->
     %% New version of observer_backend, using statistics(scheduler_wall_time)
-    Sum = lists:foldl(fun({_,A,T},{AAcc,TAcc}) -> {A+AAcc,T+TAcc} end,
+    Sum = lists:foldl(fun({{_, A0, T0}, {_, A1, T1}},{AAcc,TAcc}) ->
+                              {(A1 - A0)+AAcc,(T1 - T0)+TAcc}
+                      end,
 		      {0,0},
-		      RTInfo),
+		      lists:zip(PrevRTInfo,RTInfo)),
     case Sum of
 	{0,0} ->
 	    0;
diff --git a/lib/observer/src/etop_txt.erl b/lib/observer/src/etop_txt.erl
index 3b4c176478..6b8f9df24f 100644
--- a/lib/observer/src/etop_txt.erl
+++ b/lib/observer/src/etop_txt.erl
@@ -22,35 +22,35 @@
 
 %%-compile(export_all).
 -export([init/1,stop/1]).
--export([do_update/3]).
+-export([do_update/4]).
 
 -include("etop.hrl").
 -include("etop_defs.hrl").
 
--import(etop,[loadinfo/1,meminfo/2]).
+-import(etop,[loadinfo/2,meminfo/2]).
 
 -define(PROCFORM,"~-15w~-20s~8w~8w~8w~8w ~-20s~n").
 
 stop(Pid) -> Pid ! stop.
 
 init(Config) ->
-    loop(Config).
+    loop(#etop_info{},Config).
 
-loop(Config) ->
-    Info = do_update(Config),
+loop(Prev,Config) ->
+    Info = do_update(Prev,Config),
     receive 
 	stop -> stopped;
-	{dump,Fd} -> do_update(Fd,Info,Config), loop(Config); 
-	{config,_,Config1} -> loop(Config1)
-    after Config#opts.intv -> loop(Config)
+	{dump,Fd} -> do_update(Fd,Info,Prev,Config), loop(Info,Config);
+	{config,_,Config1} -> loop(Info,Config1)
+    after Config#opts.intv -> loop(Info,Config)
     end.
 
-do_update(Config) ->
+do_update(Prev,Config) ->
     Info = etop:update(Config),
-    do_update(standard_io,Info,Config).
+    do_update(standard_io,Info,Prev,Config).
 
-do_update(Fd,Info,Config) ->
-    {Cpu,NProcs,RQ,Clock} = loadinfo(Info),
+do_update(Fd,Info,Prev,Config) ->
+    {Cpu,NProcs,RQ,Clock} = loadinfo(Info,Prev),
     io:nl(Fd),
     writedoubleline(Fd),
     case Info#etop_info.memi of
diff --git a/lib/observer/src/observer_pro_wx.erl b/lib/observer/src/observer_pro_wx.erl
index ee6829b847..f07b9e295a 100644
--- a/lib/observer/src/observer_pro_wx.erl
+++ b/lib/observer/src/observer_pro_wx.erl
@@ -511,7 +511,13 @@ table_holder(#holder{info=Info, attrs=Attrs,
 	    table_holder(S0);
 	{dump, Fd} ->
 	    EtopInfo = (S0#holder.etop)#etop_info{procinfo=array:to_list(Info)},
-	    etop_txt:do_update(Fd, EtopInfo, #opts{node=Node}),
+            %% The empty #etop_info{} below is a dummy previous info
+            %% value. It is used by etop to calculate the scheduler
+            %% utilization since last update. When dumping to file,
+            %% there is no previous measurement to use, so we just add
+            %% a dummy here, and the value shown will be since the
+            %% tool was started.
+	    etop_txt:do_update(Fd, EtopInfo, #etop_info{}, #opts{node=Node}),
 	    file:close(Fd),
 	    table_holder(S0);
 	stop ->
diff --git a/lib/runtime_tools/src/observer_backend.erl b/lib/runtime_tools/src/observer_backend.erl
index e943fb4a3e..b27bc63d15 100644
--- a/lib/runtime_tools/src/observer_backend.erl
+++ b/lib/runtime_tools/src/observer_backend.erl
@@ -314,13 +314,12 @@ etop_collect(Collector) ->
 
     case SchedulerWallTime of
 	undefined ->
-	    spawn(fun() -> flag_holder_proc(Collector) end),
+            erlang:system_flag(scheduler_wall_time,true),
+            spawn(fun() -> flag_holder_proc(Collector) end),
             ok;
 	_ ->
 	    ok
-    end,
-
-    erlang:system_flag(scheduler_wall_time,true).
+    end.
 
 flag_holder_proc(Collector) ->
     Ref = erlang:monitor(process,Collector),