Re: upcoming meeting 2022-05-25 14:00 CEST

[Hannes Mehnert <hannes@xxxxxxxxxxx>]

Hello,

thanks for the interesting discussions at the meeting last Wednesday.

The next meeting will be on June 8th at 14:00 CEST (again on 
https://whereby.com/ocamllabs). The agenda and minutes at 
https://pad.data.coop/jgZ3NnyETWaaIT-5FM8ceA# (ics attached)
The minutes from last meeting are below.


Best,

Hannes

# Mirage 2022-05-25

attendees: Pierre (@palainp), Taka (@TImada), Thomas (@talex5), Mindy 
(@yomimono), renato, Romain (@dinosaure)
# Introduction
- hannes worked a bit on qubes-mirage-firewall and boot issues (see 
https://github.com/QubesOS/qubes-issues/issues/6162 and 
https://github.com/Solo5/solo5/pull/516)
- pierre wants to integrae the qubes-mirage-firewall into the qubes 
community repository so others can easily install that; also sshfs 
unikernel (using yomimono's file system (chamelon)); features he'd like: 
(a) a size function [mirage-fs has this functionality, mirage-kv does not]
- mindy wrote a file system, someone is using it -- terrifying;; there's 
no `append` in mirage-kv (what is the general kv/fs story in mirage and 
its commuity?)
- taka enjoys porting mirageos to embedded microcontrollers, developed a 
tender layer of solo5 for microcontrollers -- TI does not provide any 
hardware abstraction layers for the boards -- big issue is device drivers
- thomas didn't do much on mirageos, but next week wants to update CI to 
unblock various PRs (e.g. mirage-crypto eio support)
- renato from brazil, works at mariegold on tezos, wasm vm on a layer 2 
blockchain, worked on a socks client for mirageos, also some hardware 
hacking (cortex m0, entirely in C [no asm needed]), how to get OCaml 
onto small devices (16KB memory or less): linear types, statically 
allocated stuff
- dinosaure focused on cosmopolitan & esperanto, ported pthread library 
needed for OCaml by using pth (https://www.gnu.org/software/pth/), works 
fine with lwt
# memprof tracing
- revised on current memtrace library at: 
https://github.com/roburio/memtrace-mirage (also opam install 
memtrace-mirage)
- integrated together with dynamic log level adjustment and metrics 
export at https://github.com/roburio/mirage-monitoring (also opam 
install mirage-monitoring)
# qubes-mirage-firewall
- we still need to trigger the garbage collector every now and then
- dlmalloc footprint just gives the address of the highest address 
(never goes down)
- PRs: ocaml-solo5 [dlmalloc], mirage-xen [expose that info], 
qubes-firewall [mirage4 port]
-> reproducible build infrastructure targeting mirage 4

# mirage-xen
- unikernels that are executed with `--help` trigger an infinite loop

# mirage-kv vs mirage-fs
- we used to have both, but they were so similar that we merged them
- mirage-kv was then extended for the caldav implementation, and it is 
implemented by irmin
- extend mirage-kv with e.g. append? what about partial reads?
- or revive mirage-fs?
- there won't be any atomic move in chamelon!
- directories in mirage-kv are a bit weird
- feature request (a) replace something in the middle of the file:
  - `write_in_the_middle : t -> path -> offsent -> data -> unit, error 
Lwt.t`
- feature request (b) read to return chunks (or read in the middle)
  - `read_in_the_middle : t -> path -> offset -> length -> data, error 
Lwt.t`
- feature request (c) rename (key1 -> key2): currently read data of 
key1, write to key2 (tricky to rename a directory)
- let's get a PR to mirage-kv and discuss there, palainp will do that 
and mention @yomimono
# retreat in mirleft in late september / early october (details soon)

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