Replacing C

[Eric S. Raymond]

Gary E. Miller <gem at rellim.com>:
> > * A network service daemon, whether YouTube or NTP in server mode or
> > NTP in client mode, has reqirements that aren't quite as stringent.
> 
> My RasPi's, and other servers, have about 1 micro Second jitter
> between them.  Anything that makes that even a bit worse is a show
> stopper for me.
> 
> OTOH, if the OS is time stamping packets, and PPS, for the ntpd daemon
> then the daemon can tolerate 'some' jitter.

And that is the case.

It's hard to know how to estimate the average-case impact, but I see reason
for optimism.

In normal operation we can expect lots of pairs of small allocations
at UDP datagram sizes with deallocation fairly rapidly thereafter. So
the heap will have lots of churn, which is bad...

But there are two mitigating factors. One is that overall memory usage
should stay pretty low, with only one datagram being processed at a
time and the MRU list held to fixed size. The other is the range of
allocation sizes is small and the average size of allocation is too
(e.g. typically no more than 48 bytes).

What this means is that through the heap will churn a lot, it should
fragment relatively slowly. This means long intervals between GC
pauses.  I'd be surprised if the interval were typically shorter
than tens of minutes, and not surprised if it were hours.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>
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