Re: Serial port over TCP/IP

["Dr. David Alan Gilbert" <gilbertd@treblig.org>]

* Michael Buesch (freesoftwaredeveloper@web.de) wrote:
> On Sunday 06 April 2003 15:11, Dr. David Alan Gilbert wrote:
> > I keep thinking that it would be nice to have a mechanism for user space
> > char devices; it would have to have a mechanism to pass all the ioctls
> > to the process that dealt with it.
> 
> But wouldn't this make too much overhead, if implemented all in userspace?
> I say this, because nbd is also implemented in user- und kernel-space.

Sure it would have overhead; but it would be a general mechanism and
mean that the kernel didn't need lots of char drivers (except for boot
time things). Lots of devices are really just filters/wrappers over
other more basic devices (look at the growing pile of USB serial
device drivers).  Most char devices have such a low throughput that the
little overhead wouldn't make much difference, but would simplify the
kernel.

Dave
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