Re: Does Lua need a JIT?

[Dibyendu Majumdar <mobile@...>]

Hi Luke,

On 1 March 2017 at 09:26, Luke Gorrie <luke@snabb.co> wrote:
> On 22 February 2017 at 00:55, Coda Highland <chighland@gmail.com> wrote:
>>
>> IIRC Snabb uses LuaJIT to handle network packet filtering, so that's a
>> project with some pretty stringent performance requirements that a
>> non-compiled language would probably have difficulty meeting.
>
>
> Right. Snabb has a total processing budget of a few hundred CPU cycles per
> packet to e.g. read it from the network, route it, filter it, transform it,
> and write it out again. Our code has to be competitive with C written by
> Intel engineers and aggressively optimized for their latest CPUs using
> intrinsics and other compiler trickery. This is very challenging with LuaJIT
> but by some miracle we are succeeding - even in most of the inner loop code.

It would be interesting to know why you chose LuaJIT for this
application. What were the driving factors for choosing a dynamically
typed scripting language? Today, with the availability of a language
like Rust, would you still make the same choice?

Thanks and Regards
Dibyendu