open( XML, "source_of_xml.data" ) or die "I died 'cuz $!";
{
    local $/ = "</item>\n";
    my %item;
    while (<XML>) {  # read one whole <item>...</item> into $_
        for my $tag (qw/name working uptime downtime/) {
            ($item{$tag}) = m{<$tag>(.*?)</$tag>}s;  # (leave off "s",
                  # if tags are always fully contained on one line)
        }
        # now, do what you want with %item...
    }
}