One can improve performance even further by using constant.

$ cat 645310.pl
use strict;
use warnings;
use Benchmark qw/ cmpthese /;

our $verbosity = 7;
our $volume    = 1;
use constant VERBOSE => 0;

cmpthese(
  -1,
  {
    'Name7' => ' if ( $volume >= $verbosity ) { v_print3( "foo" ) }; '
+,
    'Name8' => ' if ( VERBOSE )               { v_print3( "foo" ) }; '
+,
  }
);

sub v_print3 { my $message = shift; print $message; }
__END__
$ perl 645310.pl
            Rate Name7 Name8
Name7  9442579/s    --  -74%
Name8 35826879/s  279%    --
[download]

The whole subroutine call gets optimized away:

$ perl -MO=Deparse,-x,-p -e 'use constant VERBOSE => 0; if ( VERBOSE )
+ { v_print3( "foo" ) }; '
use constant ('VERBOSE', 0);
'???';
-e syntax OK
[download]