K-ballo changed the topic of #ste||ar to: STE||AR: Systems Technology, Emergent Parallelism, and Algorithm Research | stellar.cct.lsu.edu | HPX: A cure for performance impaired parallel applications | github.com/STEllAR-GROUP/hpx | Buildbot: http://rostam.cct.lsu.edu/ | Log: http://irclog.cct.lsu.edu/
<gonidelis[m]>
ms[m]: i was lookinf for `--hpx::threads` i think
<gonidelis[m]>
it's kind of confusing that their only difference is the double colon
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<gonidelis[m]>
hkaiser: how do you use `hpx::threads` cmd line arg?
<gonidelis[m]>
`--hpx::threads=16` does not work
<gonidelis[m]>
neither `--hpx::threads 16`
<gonidelis[m]>
oh, it's not a cmd line arg.... ?
<gonidelis[m]>
hkaiser: With `--hpx:threads` I cannot more threads than my machine supports
<hkaiser>
gonidelis[m]: it's --hpx:threads (on colon)
<hkaiser>
one*
<gonidelis[m]>
i thought there was another option that would allow me to invoke more threads
<hkaiser>
more threads? more than what?
<hkaiser>
you use --hpx:threads=N to create N threads
<gonidelis[m]>
more threads than my laptop supports
<hkaiser>
sure, there is no limit
<gonidelis[m]>
I have a 16 core cpu
<hkaiser>
N can be larger than the number of cores you have, things will slow down massively if you do, though
<gonidelis[m]>
ahh strange, I get this when I try to "specified number of threads (32) is larger than number of available processing units (16): HPX(bad_parameter)"
<hkaiser>
ahh, so we do check for that after all ;-)
<hkaiser>
it does not make sense to do so anyways
<gonidelis[m]>
yeah ok
<gonidelis[m]>
I just wanted to show the bad performance beyond that num of cores
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<gonidelis>
hpx::max is quite slower than Cilk's max. They just use a simple `cilk_for` and a hyperobject to avoid races
<hkaiser>
you mean max_element?
<gonidelis[m]>
hkaiser: pm
<hkaiser>
I never measured it's performance, frankly - so it has never been optimized in any ways
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<hkaiser>
gonidelis[m]: I would use a bigger array for measurements, at least factor of 10, if not 100
<gonidelis[m]>
wow
<gonidelis[m]>
say 160m
<gonidelis[m]>
it's just that I am running 100 times each test and I am averaging it out
<gonidelis[m]>
I guess for that high number of elements I could put test_count say equal to 5