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SubjectRe: Can't sleep less than 20 ms
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Seve Underwood wrote:
> Yes the documents are poor. They should be more detailed, and fully
describe what
> the system does. However, they should actually be describing what
happens now. Just
> *think* instead of complaining. It can't be better than it is.

I don't accept that. gettimeofday() knows pretty good where inside the
tick period the system is. Rounding up to the next tick (instead of rounding up
the delta to the tick accuracy, and then rounding up to the next tick -
double rounding to me) is possible, and would allow to have a 0-10 ms sleep
period, too. It's not just a single line like deleting a + 1 in case timeout is
not zero, but I believe it's doable. I'll prepare a patch to prove it.

Linux wasn't written with real time in mind, but this doesn't mean one
can't change it to meet real time requirements better than it does now. After
all, that's the purpose of free software: when someone wants a feature, he
can implement it (and BTW, that's one of the reasons why I don't want to use
VxWorks or QNX ;-). KURT (http://hegel.ittc.ukans.edu/projects/kurt/) is a
realtime patch for Linux, so things are doable.

--
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://www.jwdt.com/~paysan/

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