Handling 100.000 packets/sec or more

[Richard Wendland]

> device polling(8) really does help _alot_ for packet floods/storms.
> for device polling to work properly (imho) you would need to set HZ to 1000.
> I dont recommend any higher HZ on a PIII.

Incidentally, setting HZ > 1000 would cause FreeBSD TCP to not comply
with RFC1323, as it would make the TCP timestamp option clock tick faster
than 1ms.  RFC1323 4.2.2 specifies the clock rate to be in the range
1 ms to 1 sec per tick.

Really the TCP timestamp option clock should be divorced from HZ before
too long, as a time will come when people will want HZ > 1000.

Actually a bit faster tick-rate is unlikely to run into much trouble in
practice, but it will cause the PAWS algorithm to stop a long running
TCP connection, see 4.2.3 of RFC1323.

	Richard
-- 
Richard Wendland				richard at wendland.org.uk