2 files changed, 136 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5db24a3
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+install:
+        sh your-fired.sh install
diff --git a/your-fired.sh b/your-fired.sh
new file mode 100644
index 0000000..dacfc37
--- /dev/null
+++ b/your-fired.sh
@@ -0,0 +1,134 @@
+#!/bin/sh
+
+WEB_CONTENT_OOM_ADJ=500
+FIREFIX_REPEAT_INTERVAL=5
+
+ploop()
+{
+    local p
+    for p in /proc/[0-9]*
+    do
+        "$@"
+    done
+}
+
+match_parent()
+{
+    # This isn't a file to which we will write (we write to the child's
+    # oom_score_adj), but this ignores processes we don't own.
+    2>/dev/null [ -w "$p"/oom_score_adj ] || return
+
+    local stat
+    2>/dev/null read stat < "$p"/stat || return
+    case "$stat" in
+        *") "?" $1 "*) echo "${p##*/}" ;;
+    esac
+}
+
+match_comm()
+{
+    local comm
+    2>/dev/null read comm < "$p"/comm || return
+    [ "$comm" = "$1" ] && echo "${p##*/}"
+}
+
+firefix()
+{
+    parent=$1
+    read parent_oom_score < /proc/$parent/oom_score
+    read parent_oom_score_adj < /proc/$parent/oom_score_adj
+
+    for child in $(ploop match_parent $parent)
+    do
+        2>/dev/null read comm < /proc/$child/comm || continue
+        [ "$comm" = 'Web Content' ] || continue
+
+        read oom_score < /proc/$child/oom_score
+        read oom_score_adj < /proc/$child/oom_score_adj
+
+        want_adj=$((parent_oom_score_adj + ${WEB_CONTENT_OOM_ADJ:-500}))
+        if [ "$want_adj" -gt "$oom_score_adj" ]
+        then
+            printf 'Setting oom_score_adj for pid=%d to %d (from %d)\n' $child $want_adj $oom_score_adj >&2
+            printf '%d\n' "$want_adj" > /proc/$child/oom_score_adj
+        fi
+    done
+}
+
+firefix_all()
+{
+    for parent in $(ploop match_comm firefox-bin)
+    do
+        firefix $parent &
+    done
+    wait
+}
+
+firefix_all_forever()
+{
+    while true
+    do
+        firefix_all
+        sleep ${FIREFIX_REPEAT_INTERVAL:-5}
+    done
+}
+
+unit_file()
+{
+    cat <<EOF
+[Unit]
+Description=$1
+[Service]
+ExecStart=$2
+[Install]
+WantedBy=default.target
+EOF
+}
+
+install_self()
+{
+    unit_file_name=$1
+    unit_executable=$2
+    unit_args=$3
+    unit_desc=$4
+
+    [ -e "$unit_executable" ] || return
+
+    if [ "$(id -u)" = 0 ]
+    then
+        service_dir=/etc/systemd/system
+        systemctl=systemctl
+        instdir=/usr/local/bin
+    else
+        service_dir=$HOME/.config/systemd/user
+        systemctl='systemctl --user'
+        instdir=$HOME/.local/bin
+    fi
+    unit_executable_installed=$instdir/${unit_executable##*/}
+
+    [ "$unit_executable_installed" -ef "$unit_executable" ] ||
+        install -D -t "$instdir" "$unit_executable" || return
+
+    [ -d "$service_dir" ] || mkdir -p "$service_dir" || return
+
+    unit_file=${service_dir}/${unit_file_name}.service
+    unit_file "$unit_desc" "$unit_executable_installed $unit_args" > "$unit_file"
+
+    $systemctl daemon-reload
+    $systemctl enable "$unit_file_name"
+    $systemctl restart "$unit_file_name"
+    $systemctl status "$unit_file_name"
+}
+
+usage()
+{
+    echo "Usage: $0 <install|once|forever>" >&2
+}
+
+case "$*" in
+    forever) firefix_all_forever ;;
+    install) install_self firefixer "$0" forever 'Firefixer - adjust firefox OOM scores';;
+    once) firefix_all ;;
+    -h|--help) usage; exit ;;
+    *) usage; exit 1 ;;
+esac