time of day (EROS/KeyKOS divergence)

[shap@eros.cis.upenn.edu]

> If it [the time of day page] is implemented by updating a page
> whenever the time changes (the resolution being low enough to make
> this feasible), there is no need to do this in the kernel. Any user
> can provide this service by waiting until a time change and updating
> an ordinary page.

I chose a kernel implementation because I may want the time of day (or
some equivalent) page to include a tick-granularity clock.  At tick
granularity, I definitely don't want to be scheduling a user-mode
process.

Otherwise, your point is well taken.

shap