1 2 Introduction 3 4The Linux 2.6 hotplug interface introduced a new approach. Instead of spawning 5a new process for each event, thus possibly creating an unmanagably large 6ammount of processes, the events (uevents) are written into a PF_NETLINK 7socket. 8 9The uevent has following format: 10actiontype@ENVVAR=VALUE\0[ENVVAR=VALUE\0[...]] 11 12The actiontype might be "add" or "remove". The action is also exported in an 13environmental variable ACTION. 14 15Reading these events by a single daemon that performs relevant actions is a 16far better approach, as it also allows smart distribution of resources and 17processing by rules, both of these features being used in both udev and 18hotplug2. 19 20The old /proc/sys/kernel/hotplug interface is still kept though, and can be 21used. If a valid value is passed to it, the application specified in the procfs 22entry gets executed along with the new method of sending event through netlink 23socket. 24