use POSIX;
my $do_fork = 1;
$SIG{CHLD} = sub {
    while( ( my $pid = waitpid(-1, POSIX::WNOHANG()) ) > 0 ){
        ...
    }
}

foreach my $node ( @devices ) {
    if( $do_fork ) {
        my $pid = fork();
        if( !$pid ) {
            do_exciting_things();
            exit 0;
        }
    } else {
        do_exciting_things();
    }
}