der Mouse <mouse@Holo.Rodents.Montreal.QC.CA> writes:

> 
> Or, if you don't trust the kernel and would rather see userland locks,
> you use the generic device and ignore the other two.

You should pick one or the other and stick with it.  Using both is
guaranteed lossage.

> The second idea is to have only ptys be tty devices in the current
> sense (stty settings and all), with the hardware device drivers being
> optimized for high throughput to user-land and no tty goop.
> Interactive logins are then handled with a user-land daemon that
> interfaces between a hardware line device and a pty master half.

I don't see any reason to do this.  With a multibyte line discipline
input function and fast handling of EXTPROC, the performance
considerations more or less go away.

(More about this when the !@##@%@#$ com driver gets committed.)