ttydev_cdevsw has no d_purge

[Hans Petter Selasky]

On Wednesday 08 August 2012 23:51:55 Konstantin Belousov wrote:
> On Wed, Aug 08, 2012 at 07:42:24PM +0200, Hans Petter Selasky wrote:
> > On Wednesday 08 August 2012 19:24:18 Ed Schouten wrote:
> > > 2012/8/8 Hans Petter Selasky <hselasky at c2i.net>:
> > > >> I have a question regarding the changed fragment of code. Why don't
> > > >> you use unr(9) KPI to manage unit numbers ?
> > > > 
> > > > Probably I could, but right now the unr interface doesn't support
> > > > pending unit free which I need for other reasons, see below.
> > > 
> > > What does `pending unit free' mean? I also would prefer it if you used
> > > unr(9) -- not just here, but across the entire USB stack.
> > 
> > It is like a drain state, where a unit is collected for free, and then
> > committed to free state when the tsw_free() is called. In the [unlocked]
> > time in between the unit cannot be re-used.
> 
> Still, why do you need such intermediate state ? You cannot reuse the unit
> number while it is in the 'pending free' still, AFAIU.

Because of the order in which structures are freed. See other e-mail.

--HPS