[erlang-questions] Strange multi-core result on windows.

Witold Baryluk <>
Mon Nov 28 23:26:23 CET 2011


On 11-28 22:12, Ian wrote:
> Hi All,
> 
> [Snip a lot of interesting replies. ]
> 
> Thanks everyone for the information.
> 
> The version of Windows in version 7 Prof. 64 bit.  The version of
> Erlang is werl -
> Erlang R14B04 (erts-5.8.5) [smp:4:4] [rq:4] [async-threads:0]
> Eshell V5.8.5  (abort with ^G)
> 
> Having thought a bit more this is what I guess is happening.
> 
> Process 1 starts and reads the data and queues up a lot (2MB) of
> messages for process 2.
> Process 2 is the heavy one. It trickles (relatively speaking)
> messages out to process 3.
> 3 passes them on to 4 before 2 has generated the next message.
> 4 is very light, and hardly does anything.
> 
> So after an initial blip, things settle down to one core running
> process 2, and two other cores coping with 3 and 4, but not working
> very hard.
> 
> What I am astonished at is the overall speed of Erlang! Its not C -
> but it gives C a run for its money.
> 
> I'll chase up percept when I have some time.

percept is extremally simple to learn and use.
After reading this message you will everything was is needed.

Check http://www.erlang.org/doc/apps/percept/percept_ug.html for official user guide.

Basically, from shell perform:

percept:profile("someoutput.dat", {mymodule, go, [some, arguments]}, [procs]).
% wait for completion
percept:analyze("someoutput.dat").
percept:start_webserver(8888).

And go to http://localhost:8888/

Thats all.

Chears,
Witek

-- 
Witold Baryluk



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