Here is an OO solution that has fixed memory limits. The API is a little strange, the bucket is destroyed when it becomes full, and upon destruction you should ensure that it gets dumped somewhere...

package Bin;
use Carp;
use strict;

# Add an element to a bucket, returns the head of the list.
sub add {
  my $self = shift;
  my $thing = shift;
  my $size = shift;
  if ($size <= ($self->{max_size} - $self->{size})) {
    $self->{size} += $size;
    push @{$self->{things}}, $thing;
    $self->{skipped} = 0;
  }
  elsif ($size > $self->{max_size}) {
    confess("'$thing' larger than a bucket ($size vs $self->{max_size}
+)");
  }
  else {
    $self->{next} ||= new Bin(@$self{'max_size', 'max_skips'});
    if ($self->{max_skips} < ++$self->{skipped}) {
      return $self->{next}->add($thing, $size);
    }
    else {
      $self->{next} = $self->{next}->add($thing, $size);
    }
  }
  return $self;
}

sub DESTROY {
  my $self = shift;
  print "Bucket size $self->{size}: @{$self->{things}}\n";
  <STDIN>;
}

sub new {
  my $self = bless {}, shift;
  $self->{max_size} = shift || 10_000_000;
  $self->{max_skips} = shift || 50;
  $self->{skipped} = 0;
  $self->{size} = 0;
  if (@_) {
    $self->add(@_);
  }
  $self;
}

package main;
my $bin = new Bin;
foreach my $cnt (9_800..10_001) {
  foreach (1, 10, 100) {
    $bin = $bin->add("$cnt\_$_", $cnt * $_);
  }
}
undef($bin);
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