my $waitdiff = $res->{iowait} - $last_proc_stat->{iowait};
$waitdiff = $diff if $waitdiff > $diff;
$res->{wait} = $waitdiff/$diff;
my $waitdiff = $res->{iowait} - $last_proc_stat->{iowait};
$waitdiff = $diff if $waitdiff > $diff;
$res->{wait} = $waitdiff/$diff;