Re: lua in kernel!

[Justin Cormack <justin%specialbusservice.com@localhost>]

On Wed, Jun 18, 2014 at 12:06 PM, Mayuresh Kathe <mayuresh%kathe.in@localhost> 
wrote:
> hello,
>
> while i was drawn to netbsd because of the upcoming lua
> support in the kernel and userland, i am quite lost about
> the probable use cases for real-world scenarios.
>
> prima-face, it feels quite strange to have a scriptable
> kernel and have that capability extended through out the
> userland.
>
> i have been googling (via lynx) and haven't found anything
> which would suggest possible use cases for the lua-in-kernel
> effort. might be because my google skills are poor.
>
> can someone with access to such a document please share the
> details?

Currently the best sources I am aware of are Marc Balmer's talks, eg
https://archive.fosdem.org/2013/schedule/event/lua_in_the_netbsd_kernel/attachments/slides/278/export/events/attachments/lua_in_the_netbsd_kernel/slides/278/kernel_mode_lua.pdf
(I think there is a video somewhere too)

There were also some discussions on the NetBSD lists too. But I think
we need to put together a better document, examples and actual code.
The current working code is for defining line disciplines.

I also have a userspace project for programming NetBSD via Lua
https://github.com/justincormack/ljsyscall which is being used in
various ways, eg for testing the NetBSD Linux compatibility layers and
programming rump kernels.

> also, if the lua-in-kernel effort does succeed, would there
> be some mechanism to turn it off while doing a customized
> build? can't figure how useful such a feature might be in
> a production environment like web-app hosting or even an
> embedded system.

Yes all the Lua support is optional, and will remain that way.

Justin