Re: PATCH: Multiprobe sanitizer

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

Ar Mer, 2006-08-16 am 15:26 -0700, ysgrifennodd Greg KH:
> What would this help out with?  Would the PCI layer (for example) handle
> this "notify the core that it can continue" type logic?  Or would the
> individual drivers need to be able to control it?
> 
> I'm guessing that you are thinking of this in relation to the disk
> drivers, have you found cases where something like this is necessary due
> to hardware constraints?

Actually it occurs everywhere because what happens is

	PCI enumerates in bus order
	Threads *usually* run in bus order

so every n'th boot your devices re-order themselves out of bus order,
and eth1 becomes eth0 for the day.

If you have a "ok now continue scanning" API then we can do

	Grab resources
	Register driver
	Go parallel
	[Slow stuff]

I was thinking if we set multithread = 2 (and define some constants)
then the core code would do

	if (multithread == WAIT)
		down(&drv->wait);


and we'd have

	pci_driver_continue_enumerating(struct pci_driver *drv) {
		up(&drv->wait);
	}