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Date: Wed, 16 Nov 2011 13:06:40 -0500
From: Dave Angel <d@davea.name>
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To: Michael Hunter <tahoemph@gmail.com>
Subject: Re: Multiple threads
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On 11/16/2011 12:55 PM, Michael Hunter wrote:
> On Wed, Nov 16, 2011 at 9:27 AM, Dave Angel<d@davea.name>  wrote:
>> On 11/16/2011 12:00 PM, Jack Keegan wrote:
>> [...] Processes [...] and the OS is generally better at scheduling them than it is at
>> scheduling threads within a single process.  If you have multiple cores, the
>> processes can really run simultaneously, frequently with very small
>> overhead.  [...]
>
> Maybe you are trying to simplify things but in a lot of cases this is
> just false.  In at least some operating systems these days a thread is
> the basic unit that is scheduled.  Processes are thread containers
> that provide other things (fds, separate address space, etc.).  The
> comment about multiple cores can be extended to multiple threads on a
> core (CMT) but applies to threads as well as processes.  Switching
> between processes tends to be heavier weight then switching between
> threads in a process because of the needs to change the address space.
>
> Just because Python sucks at threads doesn't make them heavier for the OS.
>
> That doesn't mean you shouldn't use multiprocessing.  The problem
> asked about seems a good fit to me to a single python process starting
> and managing a set of external converter processes.
>
>                Michael
>

No response is deserved.

-- 

DaveA