[Stackless] Algorithm for Stackless Scheduler
andrewfr_ice at yahoo.com
Fri Nov 21 23:31:30 CET 2008
--- On Fri, 11/21/08, Tim Kientzle <tim at metaweb.com> wrote:
> Compared to a typical OS scheduler, stackless scheduling is
> extremely lightweight,
No argument here. My comment about context switching is relative
to Stackless operations. Still fast.
> In my (somewhat limited) experience with Stackless,
> workflow issues dominate here. There are some workflow
> patterns where it's very important that a sender be able
> to queue as many outgoing messages as possible before it
> relinquishes the CPU, others where it's more important
> that the receiver begin processing as quickly as possible.
Agreed. It is these workflow patterns that I am trying to
understand more in depth.
In the case of the sender situation, (ll other things being
equal) I believe the 'queuing' is desired if there is a relatively
high overhead/fixed cost to executing the sender. However in this scenario
one should take into consideration stuff like average response time and/or
stability - is the system is sending output at least at the same rate
that it is receiving input.
As a side note, it is interesting to figure out what the exact
difference between a queue and a channel with sender preference.
Is a queue object really necessary?
> The "receiver preference" and "sender
> preference" knobs seem to provide a pretty good way to
> model those requirements.
Once again agreed. However preferences aren't really addressed in the Stackless documentation.
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