Erlang & Hyperthreading

Bjorn Gustavsson <>
Tue Feb 28 12:34:07 CET 2006

"Ryan Rawson" <> writes:

> As for performance - surely on a multicpu system with a SMP aware
> erlang running, one can expect better performance just by using
> multiple kernel threads and gaining the ability to run on several
> CPUs?

No. Most of the internal data structures need to be locked, and
locking doesn't come for free.

Also, some Erlang applications may not have more than one process
runnable at the time, even if it consists of many process. There
might be one process runnable, and all the others waiting in a receive
statement. The SMP-aware emulator will not help at all in that case.

Björn Gustavsson, Erlang/OTP, Ericsson AB

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