Re: [ANNOUNCE] udev 0.1 release

Andrew Morton
2003-04-11T22:35:29Z

Tim Hockin <thockin@hockin.org> wrote:
>
> > > A much better solution could be had by select()ing on a filehandle
> > > indicating when a new hotswap event is ready to be processed. No races,
> > > no security issues, no performance issues.
> >
> > I must say that I've always felt this to be a better approach than the
> > /sbin/hotplug callout.
>
> I've always liked this approach, too - if you look at acpid, it is designed
> to be gereically useful for this model of kernel->userland notification.
>
> With minor mods, it could become 'eventd' and handle ACPI, hotplug, netlink,
> and any other style kernel->user notice.

It also has the advantage that events are handled in reliable and repeatable
order.

Right now, if you plug and then quickly unplug a device, the unplug event can
be handled first.

It may not happen much in practice, but we have had problem with cardbus
contact bounce causing an event storm in the past. The daemon could just
swallow the first 5 insert/remove pairs and process the final insert only.

The kernel would have to drop messages on the floor at some point though.