[Zope-dev] is threading in zope useful ?

[Christian Theune]

On Wed, 2004-04-28 at 03:41, sathya wrote:
> [sathya]
> great ! If I understand correctly, if we had a zope process running on 
> an smp linux machine and doing lots of RDBMS calls we would not be 
> limited by the GIL. In essence threads running on multiple cpus would 
> probably not have to wait on acquiring the GIL as most every page 
> request results in  a ZSQL method call which in turn would release the 
> GIL. Therefore SMP may not be hindered by the GIL.
> That said , since ZEO ends up doing multiple python interpreters its 
> possibly the  more reliable approach to take advantage of SMP linux.
> please point out any flaws in my thought process .....

SMP is not doing any good for you when not running multiple Python
processes. The GIL doesn't work per CPU but for the whole system. You
very likely will end up locking your CPUs 2-n on a N-way system due to
the GIL.

ZEO actually does the trick, but you should use CPU binding for the
processes to make sure they won't affect other processors.

Cheers,
Christian