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On 2012-06-01 12:07, Björn-Egil Dahlberg wrote:
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<div>1 jun 2012 kl. 10:46 skrev "José Valim" <<a
moz-do-not-send="true" href="mailto:jose.valim@gmail.com">jose.valim@gmail.com</a>>:<br>
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<div class="im">The '++' operator does not verify that the
second argument is a list.</div>
Therefore, the compiler will rewrite the first expression
to simply:<br>
<br>
[$F,$o,$o|Bar]<br>
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<div>Yes, thanks. <span style="">For some weird reason I
thought Erlang restricted the right side to be a list in
such cases.</span></div>
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Have you made sure that you run each test in a newly
spawned process? </blockquote>
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Do you run the test for long enough time?<br>
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<div>Running in a newly spawned process did the trick, the
results are now consistent.</div>
<div>I was already running it 1000 times, here is the code
(without using spawn):</div>
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<div><a moz-do-not-send="true"
href="https://www.refheap.com/paste/2954">https://www.refheap.com/paste/2954</a></div>
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<div>I assume having a "clean" heap (reducing the chance of
garbage collection) is the reason why it is a good idea to
run benchmarks in a newly spawned process?</div>
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If you want to vary one parameter in a test, make sure all other
parameters stays the same otherwise you have no idea what you are
measuring!
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<div>Code loading, heaps, position of mars .. Everything has to be
taken into account.<br>
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The effect of Mars magnetic field on that of Earth, even if Earth's
aphelion and the perihelion of Mars were to <span class="hw">coincide
and the interplanetary distance were to be at its theoretical
minimum, is </span>negligible compared to the normal variations
in Earth's magnetic field. <br>
<br>
Therefore it's very unlikely that the relative position of Mars
would affect the probability of a memory bitflip occurring due to
cosmic radiation and thus affecting the benchmark.<br>
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Regards,<br>
Gustav Simonsson<br>
Erlang/OTP team<br>
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<div>Thanks Björn!</div>
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