Re: multithreaded environment ? (better now: multi-core environment)

From: Frank Gadegast <>
Date: Thu, 01 Dec 2011 16:18:54 +0100

Todd Lyons wrote:


>> Only one process for opendkim and because the machine is hyperthreaded,
>> its running only on one virtual CPU, wich equals 1/2 core of one CPU.
>> spamassassin is forking as many children as needed and is running
>> on all virtual CPUs, if needed.
> Right, spamassassin is, but not spamass-milter. the milter is tied to
> the libmilter library.
>> Why does opendkim not do the same ?
>> Or can it be tricked to do so ?
> This is how opendkim milter runs, one daemon that can communicate with
> the multi-threaded libmilter library, which is exactly how
> spamass-milter runs. spamass-milter just has the luxury of passing
> off all the work to an app which forks (thus capable of using multiple
> CPU's) and waiting for the answer to come back.

Thats what I mean, opendkim is only running on one CPU.

Multi-threaded on a single CPU does not help a lot these days,
where every CPU has multiple cores that are splitted again via
hyperthreading and where multi-processor machines are
quite normal also.
Specially when most other processes (sendmail or spamassassin) are
running on all virtual CPUs ...

Its only using 1/16 of the possible performance on our system.

So, why is there no (or is there ?) a opendkim-milter that will
call several processes of opendkim running on several CPUs ?

> Regards... Todd

Kind regards, Frank
PHADE Software - PowerWeb             
Inh. Dipl.-Inform. Frank Gadegast   
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Received on Thu Dec 01 2011 - 15:19:43 PST

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