[Info-vax] Reloading device drivers on x86-64 VMS

[Bob Gezelter]

On Saturday, March 7, 2015 at 8:20:42 AM UTC-5, Simon Clubley wrote:
> I don't know if you can unload and reload device drivers on IA-64
> (I've stopped at Alpha so far) or if the ability was added to Alpha
> in the last few years (I haven't done any VMS kernel mode work for
> many years) but if you can't, would it be possible to have device
> drivers for x86-64 VMS which can be unloaded and then a new version
> reloaded ?
> 
> One thing which became very clear very quickly to me was just how much
> easier it is to develop device drivers on Linux where you can do
> exactly this.
> 
> I know it's not exactly a major feature for the majority of users
> but if it's easy enough to add support for this it would be worthwhile
> as it also has production implications in being able to load some
> updated drivers without rebooting.
> 
> Simon.
> 
> -- 
> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
> Microsoft: Bringing you 1980s technology to a 21st century world

I agree with Simon and Paul, with the limitation that the capability is not generic or guaranteed, as noted by Hoff.

In doing extensive driver-level work on RSX, the ability to quiesce and reload a driver without a reboot was vital to achieving progress. It always had the limitation that you needed a quiescent device, the data structures were compatible, and there was always the degree of risk that a crash could ensue. That said, it was extremely helpful at speeding progress.

- Bob Gezelter, http://www.rlgsc.com