Re: Old/unused display bits

[Stefan Monnier]

> I don't think we should remove redisplay-dont-pause.  It was only
> turned on by default in Emacs 24.1, and it's not yet clear whether the
> non-nil is a "fits all" value.

Agreed, it's too early to remove it.

> I never used the other 2 options.  I don't think I have a slow line to
> see them in action.  It is probably safe to say that
> PERIODIC_PREEMPTION_CHECKING was not used by too many people in their
> day to day work.

We I think it's OK to remove PERIODIC_PREEMPTION_CHECKING and
redisplay-preemption-period (which is only defined if you set
PERIODIC_PREEMPTION_CHECKING).
[ BTW, it seems that in the current code, Vredisplay_preemption_period
  is read but is never initialized, unless you compile with
  PERIODIC_PREEMPTION_CHECKING.  ]


        Stefan