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Lowering resource usage with foot and systemd

by HaoZeke on 6/2/24, 10:55 PM with 30 comments

• by chme on 6/3/24, 7:12 AM

  The title is kinda odd. "Lowering resource usage of foot with systemd" sounds more appropriate.

  Not knowing that foot is a terminal emulator, I assumed that foot is some kind of improved resource manager that allows for a general lesser resource usage.

• by tupolef on 6/3/24, 4:26 AM

  I don't want to switch to Wayland for now, but I will check foot when I do.

  I do the same thing with URxvt as a systemd daemon, Tmux as a transient service with systemd-run from .bashrc, and a script in i3wm to run URxvtd client or hide/get the window.

  The way I use to run Tmux from a transient service locally and in ssh with the same .bashrc is nice I think. Tmux will survive the terminal and even if I close my session and come back to it:

    #!/usr/bin/env bash
    # ~/.bashrc: sourced by bash(1) for non-login shells.
    
    # If not running interactively, don't do anything
    case $- in
      *i*) ;;
      *) return ;;
    esac
    
    chmod 700 ~/.bashrc.d
    chmod 600 ~/.bashrc ~/.bashrc.d/*
    
    # check if we are already in a Tmux session and not in ssh then open/attach the default one
    if [[ ! "${TERM}" == "tmux"* ]] && [[ -z "${TMUX}" ]] && [[ -z "${SSH_CONNECTION}" ]] && command -v tmux 1> /dev/null; then
      # attach or start the local default Tmux session
      if systemctl --quiet $([[ $(id -u) != 0 ]]; echo "--user") is-active tmux-local-$(id -un).scope; then
        tmux -L local-$(id -un) attach-session -t local-$(id -un) ; exit
      fi
      systemd-run -q --unit tmux-local-$(id -un) --scope $([[ $(id -u) != 0 ]] && echo "--user") tmux -L local-$(id -un) new-session -s local-$(id -un) ; exit
    elif [[ -z "${TMUX}" ]] && [[ -n "${SSH_CONNECTION}" ]] && command -v tmux 1> /dev/null; then
      # attach or start the ssh default Tmux session
      if systemctl --quiet $([[ $(id -u) != 0 ]]; echo "--user") is-active tmux-ssh-$(id -un).scope; then
        tmux -L ssh-$(id -un) attach-session -t ssh-$(id -un) ; exit
      fi
      systemd-run -q --unit tmux-ssh-$(id -un) --scope $([[ $(id -u) != 0 ]] && echo "--user") tmux -L ssh-$(id -un) new-session -s ssh-$(id -un) && exit || echo 'Tmux Systemd unit failed/exited'
    
    fi
    
    # if Tmux is not installed or if we are inside a Tmux session continue the sourcing
    for file in ~/.bashrc.d/*.bashrc;
    do
      source "${file}"
    done

• by emmanueloga_ on 6/3/24, 1:17 AM

  I never heard about it but foot is a terminal emulator with some server mode [1].

  —

  1: https://wiki.gentoo.org/wiki/Foot#Server_mode_configuration

• by FrostKiwi on 6/3/24, 2:57 AM

  Really enjoyed foot! Runs along the same lines of emacs server and emacsclient.

  I ended up dropping it for the same reason I dropped emacs server. There are rare edge cases which causes the server to hang and thus taking down not just one instance of your work, but all of it. Losing the resilience of multiple processes is not worth the RAM it saves, not on modern hardware.

• by NewJazz on 6/3/24, 5:26 AM

  IMO the best part of the foot client/server setup is not lower memory usage, but faster terminal opening time. Starting alacritty is kinda slow. Maybe not a second, but noticeable. Starting foot standalone is definitely faster. Opening a foot window via an already running server is near instant.

• by yjftsjthsd-h on 6/3/24, 2:55 AM

  > Right of the bat, it is rather evident that this configuration will spawn two instances of foot, one for each scratchpad.

  > Figure 1: Snapshot of memory consumption (from btop), clients take around 10x less memory

  By all means use a server/clients approach if it reduces per-process memory, but it's probably not as bad as it looks, because AFAIK the actual executable only gets loaded once and then reused. So each process has its own data in RAM, but the executable/binary only gets loaded the once.

  Also, if this is a problem maybe revisit your choice of terminal? It's annoyingly hard to get a total (or more likely I just don't know how to get it), but every number I can seem to find says alacritty is only using <2MB total on my box, so your 27M max on foot looks... weird. Like, I can run a full standalone terminal in the size of your client; I appreciate that it might have features that make it worthwhile, but consider the tradeoffs?

• by MuffinFlavored on 6/3/24, 3:59 PM

  > foot is a lightweight terminal emulator designed for Wayland, focusing on minimal resource usage while maintaining performance.

  https://codeberg.org/dnkl/foot

  For those out of the loop

• by paulcarroty on 6/3/24, 4:25 PM

  Still no ligatures support in foot, which is critical in dev environment.

• by nurettin on 6/3/24, 4:40 AM

  This is why I run xvfb in systemd instead of using something like xvfb-run which spawns a new virtual display every time you run it.

• by sed3 on 6/3/24, 6:16 AM

  > Since I often work in strong sunlight, I often want to reconfigure my terminal to use a light or a dark scheme depending on the time of day.

  Konsole can switch color theme with simple dbus message.

  For the rest, I use tmux sessions and some scripts. When I restart computer, all terminal windows with remote ssh sessions get restored.

  I do not need any modifications on server (except tmux or screen package).

• by Zambyte on 6/3/24, 1:01 PM

  I thought the "written by human not AI" badge was kind of cute, then I clicked on it. It seems like people pay for the "right" to put that badge on their page? The author was scammed.