Messages in this thread | | | Date | Sun, 29 Nov 1998 12:00:01 +0100 | From | Martin Mares <> | Subject | Re: unkown PCI device |
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Hello,
> Grrr... don't you even think of it! > > People paid money for those servers. How does /proc/pci hurt you? > If you don't like it, you have the config option. Maybe there should > never have been a /proc/pci, but it's there now and I'm addicted to it.
Yes, there never should have been /proc/pci and if there is, it wasn't ever intended to be parsed by programs. There is _no_ exact format specification you can rely on when writing a parser. It's The Maintainer's Nightmare -- when doing any changes (including bug fixes), you never know what application attempting to parse it will the changes break. And it consumes about 16KB of precious kernel memory and this amount would be increasing for ever if I didn't decide not to synchronize the tables with master PCI ID list any more. Aside from that, the present implementation breaks on machines with lots of PCI devices (it just runs out of buffers and truncates the list).
> One common complaint about Linux is that is changes too often. > This wouldn't be just a new version freaking out a PHB, but a real > incompatible change.
Nobody knows what applications will break -- maybe only some ancient X server, maybe more. I've attempted to identify such applications by printing a warning message when they try to open /proc/pci.
If only stone-age X servers will break, the right solution is probably a preload-library replacing open(). If there are more such applications, we can solve it easily by making /proc/pci a link to /var/run/proc-pci in the kernel and creating a utility generating this file. But in all cases, I'll do my best to keep this thing outside the kernel.
> It's not even a change we need for standards > compliance. If /proc/pci somehow impedes development, please explain.
As mentioned above, it is unmaintainable and it probably isn't worth of the 16KB of kernel memory just for sake of few prehistoric apps. (Anyway, you can keep it a configurable feature, but it would probably mean all the distribution makers will leave it compiled in as they do now.)
Have a nice fortnight -- Martin `MJ' Mares <mj@ucw.cz> http://atrey.karlin.mff.cuni.cz/~mj/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "640K ought to be enough for anybody." -- Bill Gates, 1981
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