ides-set-oom-adj

#! /bin/sh
#
PROG="$(basename $0)"

## defaults

DEFAULT_MAX_UID=500
DEFAULT_OOM_ADJ=-17


## usage

usage () {
cat <<EOF
Usage: $PROG [options]

Set the '/proc/PID/oom_adj' value for all processes owned by system users.
A "system user" is any user whose UID is less than $DEFAULT_MAX_UID (you can
change this value with the '-m' option).

This is a crude hack to workaround the lack of cgroups support in GridEngine 6.2.

Options:

  --max-uid, -m NUM
              Only affect processes whose real user ID is less than NUM.
              (Default: $DEFAULT_MAX_UID)

  --oom-adj, -a NUM
              Set the '/proc/PID/oom_adj' value to NUM (default: $DEFAULT_OOM_ADJ).

  --no-act, -n
              Print what would have been done, but do not actually make any change
              to the system.

  --help, -h  Print this help text.

EOF
}


## helper functions
die () {
  rc="$1"
  shift
  (echo -n "$PROG: ERROR: ";
      if [ $# -gt 0 ]; then echo "$@"; else cat; fi) 1>&2
  exit $rc
}

log () {
    lvl="$1"
    shift
    if [ "${VERBOSE:-0}" -ge "$lvl" ]; then
        echo "$@"
    fi
}

warn () {
  (echo -n "$PROG: WARNING: ";
      if [ $# -gt 0 ]; then echo "$@"; else cat; fi) 1>&2
}

have_command () {
  type "$1" >/dev/null 2>/dev/null
}

require_command () {
  if ! have_command "$1"; then
    die 1 "Could not find required command '$1' in system PATH. Aborting."
  fi
}

is_absolute_path () {
    expr match "$1" '/' >/dev/null 2>/dev/null
}


## parse command-line

short_opts='a:hm:nv'
long_opts='help,max-uid:,oom-adj:,no-act,dry-run,just-print,verbose'

if [ "x$(getopt -T)" != 'x--' ]; then
    # GNU getopt
    args=$(getopt --name "$PROG" --shell sh -l "$long_opts" -o "$short_opts" -- "$@")
    if [ $? -ne 0 ]; then
        die 1 "Type '$PROG --help' to get usage information."
    fi
    # use 'eval' to remove getopt quoting
    eval set -- $args
else
    # old-style getopt, use compatibility syntax
    args=$(getopt "$short_opts" "$@")
    if [ $? -ne 0 ]; then
        die 1 "Type '$PROG --help' to get usage information."
    fi
    set -- $args
fi

while [ $# -gt 0 ]; do
    case "$1" in
        --oom-adj|-a) oom_adj="$2"; shift ;;
        --max-uid|-m) max_uid="$2"; shift ;;
        --no-act|--dry-run|--just-print|-n) maybe=echo ;;
        --verbose|-v) verbose='-v'; VERBOSE=$(expr ${VERBOSE:-0} + 1) ;;
        --help|-h) usage; exit 0 ;;
        --) shift; break ;;
    esac
    shift
done

## main

require_command expr
require_command ps

if [ -z "$max_uid" ]; then
    max_uid="$DEFAULT_MAX_UID"
fi
if [ -z "$oom_adj" ]; then
    oom_adj="$DEFAULT_OOM_ADJ"
fi

# either print command (echo) or execute (eval) it
if [ -z "$maybe" ]; then
    maybe=eval
fi

ps -e -o pid,uid,ruser,cmd,command -ww --no-headers | ( \
    while read pid uid ruser cmd command; do
        if expr match "$command" '^\[' >/dev/null; then
            log 1 "Process $pid ('$cmd') is an in-kernel process; skipping it."
            continue
        fi
        if [ "$uid" -lt "$max_uid" ]; then
            current_oom_adj=$(cat "/proc/$pid/oom_adj")
            if [ -z "$current_oom_adj" ]; then
                # the process has finished and disappeared while we
                # were running, so skip it
                continue
            fi
            log 2 "Examining process $pid ('$cmd'), owned by user '$ruser' ..."
            if [ "$current_oom_adj" -ne "$oom_adj" ]; then
                log 1 "Process $pid's current 'oom_adj' value is $current_oom_adj, setting it to $oom_adj instead."
                $maybe echo "$oom_adj" '>' "/proc/$pid/oom_adj"
            else
                log 2 "Process $pid's current 'oom_adj' value is already $oom_adj, nothing to do."
            fi
        fi
    done
)