#!/bin/bash
#%# family=auto

: << EOF
=head1 NAME

kernel_same_page_merging - Outputs various metrics about kernel same page merging.

=head1 AUTHOR

Michael Grote - git.mgrote.net

=head1 LICENSE

GPLv3 or later

SPDX-License-Identifier: GPL-3.0-or-later

=head1 MAGIC MARKERS

  #%# family=auto
  #%# capabilities=autoconf

EOF

# Variablen
ksm_dir_run="/sys/kernel/mm/ksm/run"

function print_labels {
cat << EOF
graph_title kernel same page merging
graph_category system
graph_order pages_unshared pages_volatile pages_shared pages_sharing
pages_shared.info how many shared pages are being used
pages_sharing.info how many more sites are sharing them i.e. how much saved
pages_unshared.info how many pages unique but repeatedly checked for merging
pages_volatile.info how many pages changing too fast to be placed in a tree
pages_shared.label pages shared
pages_sharing.label pages sharing
pages_unshared.label pages unshared
pages_volatile.label pages volatile
pages_shared.draw AREASTACK
pages_sharing.draw AREASTACK
pages_unshared.draw AREASTACK
pages_volatile.draw AREASTACK
EOF
}



# wenn parameter = ...
if [ "$1" = "autoconf" ]; then
  # prüfe ob ksm aktiviert ist
  if [ ! -f "$ksm_dir_run" ]; then
    echo "no ($ksm_dir_run not found)"
    exit 0
  fi
  echo yes
  exit 0
fi

if [ "$1" = "config" ]; then
  # setze label
  print_labels
  exit 0
fi

echo pages_shared.value $(cat "/sys/kernel/mm/ksm/pages_shared")
echo pages_sharing.value $(cat "/sys/kernel/mm/ksm/pages_sharing")
echo pages_unshared.value $(cat "/sys/kernel/mm/ksm/pages_unshared")
echo pages_volatile.value $(cat "/sys/kernel/mm/ksm/pages_volatile")