[erlang-questions] My frustration with Erlang

Paul Brown <>
Fri Sep 12 23:03:39 CEST 2008

On Sep 12, 2008, at 6:52 AM, Joel Reymont wrote:

> [...]
> I suppose this is a reflection of the load on the system, although CPU
> usage never goes past 300% which tells me that no more than 3 cores
> are used by Erlang.
> [...]

You know, my own experience with R12B on Mac OS X (analogous machine  
to yours, 8 cores, buncha RAM, fast disks, etc.) was similar:

http://is.gd/2y0j = http://mult.ifario.us/p/use-the-cores-erl
http://is.gd/2y0g = http://www.erlang.org/pipermail/erlang-questions/2008-January/032386.html 

I'll chalk it up to something like the preemption timing or other low- 
level characteristics of MacOS.  You need to head to a larger number  
of OS processes running Erlang VMs to get your utilization up, and  
this seems like a sensible reality for multicore in general, as OS  
scheduling and Erlang scheduling are two independent behaviors from  
which you need to select the happy medium.


Paul Brown

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