On Tue, Jan 29, 2013 at 8:07 PM, Miloslav Trmač <mitr@xxxxxxxx> wrote: > On Sun, Jan 27, 2013 at 2:54 PM, Jaroslav Reznik <jreznik@xxxxxxxxxx> wrote: >> = Features/SystemdHardwareDatabase = >> https://fedoraproject.org/wiki/Features/SystemdHardwareDatabase >> >> Feature owner(s): Kay Sievers <kay at redhat dot com> >> >> The udevd service has a long history of managing kernel devices. Besides >> generating events when devices are discovered or removed it maintains a >> dynamic, stateless database of all available devices including meta data about >> them. With Fedora 19 we want to substantially enhance the metadata that udev >> keeps for each device, by augmenting it from a userspace database of non- >> essential information, that is indexed by device identification data such as >> PCI/USB vendor/product IDs. > > Some years ago all hardware data was moved out of various separate > packages into the "hwdata" package (even if it meant moving it out of > the original upstream source). The feature page doesn't even mention > the hwdata package. AFAICS this The hwdb is drop-in directory based, which means: - additionally installed data overwrites shipped data - stuff with the same file name in /etc/ disables stuff in /usr/lib/ Users can just install update packages, or add their own files, which will not conflict with the default shipped data. > 1) Duplicates the data. > 1a) Will the two databases be kept in sync? How will that happen? No. In the long run the old textual files will no longer be used. It was a really bad idea from the start to parse several megabytes of ever-growing text files for every query submitted; it was showing up as CPU spikes in all sort of profiles. That model of implementing low-level operating system tools should just not be continued in the future. The systemd hwdb data can be queried almost for free. > 1b) What is the long-term goal? Will one of the two go away? If > so, how and when? Phase out hwdata, as soon as things have stabilized enough, the remaining users have been converted, and people get used to the new data source. > 2) Breaks the hwdata-vs-code separation that was created earlier. > What were the reasons of the separation, and why are they no longer > applicable now? It's just not needed because of the /usr/lib/ etc/ and drop-in directory overwrite logic, that works for all other default vs. custom/update settings. It could go into another package when things have settled down, but there will be lots of other data in the same database shipped by systemd itself, like keymaps, power settings whitelists, which we cannot really and should not move out to a generic package. So all that theoretic code vs. data separation will not really mean much in the end, the hwdb will be much more than what hwdata was. It will take over quite a lot of what udev rules do today, and these should live in the main package. We will see, I think it's too early at the moment to introduce rather needless packaging complexities and dependencies for something that is still under development. Kay -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
