Re: [Algorithms] General purpose task parallel threading approach

[Sebastian S. <seb...@gm...>]

On Sun, Apr 5, 2009 at 1:10 AM, Jarkko Lempiainen <al...@gm...> wrote:

> I think you really need to target for both task and data level parallelism
> to make your game engine truly scalable for many-core architectures. I
> don't
> see why you would need to consider the cost of context switching in
> relation
> to const of a task execution though since if you got a job queue, each
> worker thread just pulls tasks from the queue without switching context.


The problem is when you have a task spawn N other tasks and then wait for
their results, the core running that worker needs to do something until the
two sub-tasks have completed. In practice, I do think that this kind of
synchronisation (specifically the fork-and-join model) will be extremely
common in the future, which means that context switch needs to be fast
(Windows 7's user mode scheduling may be useful here - in fact I believe
that's what Microsoft's native concurrency runtime uses, while the .Net one
is backed by thread pools, I believe).



-- 
Sebastian Sylvan
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