nvidia-smi dmon adapter: 525, 530, 535, 545

nvidia-smi

#!/usr/bin/env bash

# MIT license (c) 2022-2024 https://github.com/slowpeek
# Homepage: https://gist.github.com/slowpeek/006680bb06e671bc489d4a3274ff3d19

: <<'README'

Applicable nvidia driver versions: 525, 530, 535, 545, 550

ABOUT --

  Since nvidia driver 525, field parsing in KDE system monitor stumbled twice:

  - 525: `nvidia-smi dmon` appends a tailing space on each line printed.
    Fixed in plasma 5.27 [1]

  - 535: There are extra columns in `nvidia-smi dmon -s pucm` output.
    Fixed in plasma 5.27.7 [2]

  Some systems won't receive the fixes like ubuntu 22.04 running plasma
  5.24. This tool can be used instead to normalize `nvidia-smi dmon` output
  before passing it to the parser.

  The tool only changes anything either when called by ksystemstats or when
  there is NVIDIA_SMI_ADAPTER=y env var. Otherwise, it just runs the nvidia-smi
  binary as-is.

  [1] https://invent.kde.org/plasma/ksystemstats/-/commit/d42ab99437
  [2] https://invent.kde.org/plasma/ksystemstats/-/commit/7f9ead6bdd

INSTALLATION --

  Save the script as 'nvidia-smi' under /usr/local/bin/, make it executable and
  reboot or relog.

TECHNICAL DETAILS --

  `dmon -s pucm` cols expected by KDE system monitor: gpu pwr gtemp mtemp sm mem
  enc dec mclk pclk fb bar1

  Since 535:
  - extra cols in `dmon -s u`: jpg, ofa

  Since 535 (excluding some 535.x.y and 545):
  - extra cols in `dmon -s m`: ccpm

README

set -eu

is_comment () {
    [[ $1 == '#'* ]]
}

puts () {
    printf -- '%s\n' "$1"
}

# Option: set custom nvidia-smi binary with NVIDIA_SMI env var
nvidia_smi=${NVIDIA_SMI:-/usr/bin/nvidia-smi}

# Option: force the adapter, even if not called by ksystemstats, with
# NVIDIA_SMI_ADAPTER=y env var
force_adapter=${NVIDIA_SMI_ADAPTER:-n}

pass=y
# Only do something in 'dmon' mode
if [[ ${1-} == dmon ]]; then
    # Only do something if called by ksystemstats OR forced
    # shellcheck disable=SC2046
    if [[ $(ps -o comm= $(ps -o ppid= $$)) == ksystemstats || $force_adapter == y ]]; then
        pass=n
    fi
fi

[[ $pass == n ]] || exec "$nvidia_smi" "$@"

adapter () {
    read -r h1 || return

    if ! is_comment "$h1" || ! read -r h2; then
        puts "$h1"
        return
    fi

    if ! is_comment "$h2"; then
        puts "$h1"
        puts "$h2"
        return
    fi

    read -ra h1_list <<< "${h1:1}"

    # Figure out indices for cols added in 535 and collect $header out of the
    # rest
    header=() del=() col=0
    for el in "${h1_list[@]}"; do
        if [[ $el == @(jpg|ofa|ccpm) ]]; then
            del+=("$col")
        else
            header+=("$el")
        fi

        (( ++col ))
    done

    # Header with 535 cols removed
    puts "# ${header[*]}"

    while read -r line; do
        ! is_comment "$line" || continue

        read -ra row <<< "$line"

        # Remove 535 cols from $row
        for col in "${del[@]}"; do
            unset -v 'row[col]'
        done

        puts "${row[*]}"
    done
}

"$nvidia_smi" "$@" | {
    adapter
    tee
}

exit "${PIPESTATUS[0]}"