I'm using storm control as a work-around for a bug in Apple Thunderbolt displays that periodically floods the network with bogus traffic.  The switch is a 3750-E stack running 15.0(2)SE8.  Here's the relevant configuration:

errdisable recovery cause storm-control

errdisable recovery interval 180

!

interface GigabitEthernet1/0/1
switchport access vlan 100
switchport mode access
switchport voice vlan 200
no logging event link-status
mls qos trust dscp
storm-control broadcast level pps 1k
storm-control multicast level pps 50k
storm-control unicast level pps 150k
spanning-tree portfast

!

I get a few syslog messages a day confirming that storm control is active, showing a "packet filter" applied.

%STORM_CONTROL-3-FILTERED: A Unicast storm detected on Gi1/0/1. A packet filter action has been applied on the interface.

My question is, what exactly is meant by "Packet Filter"?  Is it filtering the traffic entirely, or rate limiting to 150,000 pps?