On Wed, Dec 29, 2010 at 05:08:56PM +0100, José Félix Ontañón wrote: > El día 29 de diciembre de 2010 01:18, Scott James Remnant > <scott@xxxxxxxxxxxx> escribió: > > 2010/12/28 Lennart Poettering <lennart@xxxxxxxxxxxxxx>: > >> On Tue, 28.12.10 14:14, José Félix Ontañón (felixonta@xxxxxxxxx) wrote: > >> > >>> Hi, everybody! > >>> > >>> Maybe this is kinda silly question but, I wonder why isn't > >>> "ID_VENDOR_FROM_DATABASE / ID_MODEL_FROM_DATABASE"-like properties > >>> imported by default using the pretty /lib/udev/usb-db and > >>> /lib/udev/pci-db commands for every founded pci/usb device? > >>> > >>> I mean, by adding this simple rules: > >>> > >>> SUBSYSTEMS=="usb", IMPORT{program}="usb-db %p" > >>> SUBSYSTEMS=="pci", IMPORT{program}="pci-db %p" > >>> > >>> I think this properties are very useful for apps that discover > >>> hardware through udev, so they will not have to reinvent the wheel by > >>> finding vendor/product names by themselves. Don't you think? > >> > >> The database lookup is a linear search. As long as we invoke it only for > >> a small subset of devices that doesn't really matter much. But if we > >> start to look it up for every device we should probably spend the time > >> to improve the db lookup first. > >> > >> It's simply a question of efficiency. > >> > > One thing that might be interesting is if we could do the lookup at > > the point of query, then store the answer back in the db for others to > > use later. > > > > That way we're efficient if nobody cares, and lose that efficiency > > when they do (but only for the devices they query), and subsequently > > efficient because the answer is cached. > > > > This veers a bit dangerously towards having apps that link with > > libudev process rules though? > > > > Scott > > > > First thing coming to my mind: there's not enough pci/usb devices > present on the system for increasing the computational cost > significantly. How can you say that? I see systems with thousands of PCI devices on it as being very common in some areas. > I think it's quite comfortable, for me as desktop app coder, to > delegate on udev the vendor/model name querying, more if we think udev > provides the cool pci-db and usb-db commands. Again, what's wrong with using libpci directly for this? That's what it is there for. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html