[Techtalk] Kernel Stuff (was Re: Theory vs. practice)

[Kai MacTane]

At 1/15/02 03:35 PM , Raven, corporate courtesan wrote:
>         Okay, I can see that that's bad.  Is there a way to quickly
>check which processes are freeing up resources rather than requesting
>them, and then assign a higher priority to those?  Something to the
>effect of "need $100, who's releasing $100?  You?  Up front!".

What would be really nice is if you could have two separate queues, one for 
deposits and another for withdrawals. (Or, since banks also have the option 
that you might need to other things, one "Express Lane" that's only for 
people who are *only* performing a deposit, and any other operation means 
you go to the normal line.)

Agg. The problem is, that would require two tellers. (And I *know* this 
isn't what the kernel does in an SMP configuration! There are much better 
uses for a whole CPU!)

>You could even do some sort of secondary categorization, such that if you
>had a Platinum account needing $100, and you had a Gold account waiting
>to deposit $100 and a Silver account waiting to deposit $100, that the
>Gold account would get priority over the silver even under the new
>"who's got $100" system.

Using two queues, you just order each queue independently the way you'd do 
the one. But I'm still not sure if there's any way to implement plural 
queues with only one CPU in this analogy. (Or maybe we're just trying to 
push the analogy too far?)

                                                 --Kai MacTane
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                                                 --Ministry,
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