On Tue, May 08, 2007 at 02:15:54PM -0700, David Miller wrote: > From: Linus Torvalds <[EMAIL PROTECTED]> > Date: Tue, 8 May 2007 08:27:34 -0700 (PDT) > > > Threading at the bus level just inevitably means things like random > > numbers for devices depending on some timing/scheduling issue. That's > > nasty. > > I hadn't considered this issue, so ignore the other reply I made to > this thread. Although as an aside I'm starting to become of an > opinion that device numbering doesn't matter. Every device should > have a unique ID of sorts, or a unique physical location, and that > should factor into the thing users use to refer to the object.
We pretty much already do this today. For block devices, as an example, look at /dev/disk/ which udev creates so that you can handle block devices being discovered in any order possible. > Anyways, it would be nice, however, to really deal with the case like > when the IDE layer is waiting for a probe to port X to timeout, > meanwhile we could be initializing the networking card. > > Another bad case is, as you mentioned, SCSI bus resets and SAS/FC > fabric scans. Those take several seconds if not longer and it's > really stupid to not be able to do other things during that time. Yes, because of that, I think this kind of multi-probe stuff should be done in the IDE/SATA/SCSI bus code, not in the PCI code, as PCI "normally" does not have any speed issues. thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
