Re: MirageOS and my recent involvement

[Hannes Mehnert <hannes@xxxxxxxxxxx>]

On 17/12/2023 11:33, Thomas Gazagnaire wrote:
> > Some repositories in the mirage organization are suffering from bitrot, and/or 
> > lack of cleanups or reviews (such as the ocaml-solo5 PR waiting since a long 
> > time for proper reviews that would enable to use OCaml 5) -- my personal 
> > experience with OCaml 5 from a resource perspective is not very good, that's 
> > why I don't really care about that too much (and am happy that 4.14 is under 
> > long-term support).
> Do you have some reproducible case for the OCaml5 resource usage? 5.1.1 is 
> shipping with a few improvements and it would be great to see if that fixes 
> what you have observed.

Short answer is no. Longer answer is that I've no incentive to move to 
OCaml 5.1.1. There's still no memtrace/statmemprof, thus debugging any 
memory issues is tedious.
"Reproducible cases" - well, I observed for example a dream webserver 
(builder-web), builder, albatross -- all over a week of time (graphing 
memory usage, and CPU usage) - and when using OCaml 5, they used nearly 
double the amount of memory. Since then, I put an upper bound on ocaml < 
5 into the opam files that are used for building their reproducible 
binary packages. So, these cases are reproducible by deploying them as 
real systems, and looking at them over time.

Best,

Hannes