Erlang on the niagara

Ulf Wiger <>
Thu Jun 8 20:45:31 CEST 2006


Den 2006-06-08 19:01:23 skrev David Hopwood  
<>:

> Joe Armstrong (AL/EAB) wrote:
>> Why can't we speed up beyond a factor 7 - who knows? - at some stage
>> things do get serialised, there is after all only one disk on the
>> machine, and the SMP erlang has to serialise all disk I/O, even if the
>> programs generating data run in parallel, [...]
>
> Do you mean that it does disk I/O in a single OS thread, or with a mutex
> around the I/O code, or just that the I/O is serialized at the hardware
> bus level?

AFAIK, the whole I/O subsystem in OTP R11B is protected with a single
big mutex.

BR,
Ulf W
-- 
Ulf Wiger



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