> Alessandro Rubini wrote:
> >
> >> 1. Is there any centralized "organ" to coordinate and assign
> official
> >> major numbers?
> >
> >Yes. Look at "Documentation/devices.txt".
> >
> >However, I *strongly* suggest to use dinamic assignments of a major
> number.
> >There's plenty of documentation about this feature, but I can send
> you
> >the material if you need it.
>
>
> If I have a driver with dynamic major number, it won't know it's major
> number until after it's loaded into the kernel. Is there any
> standarized ways of retrieving it's major number, so the special file
> in the /dev directory can be updated? /proc? (If you do have some
> automated scripts to do this, can you please send it to me.)
That's where the devfs comes into play - the driver special files are
created by the kernel, and you driver only has to tell the kernel what
it's name should be.
Vladimir Dergachev
>
> >> 3. Since only one process runs while executing in the kernel, all
> >> other processes "hangs". How long is it reccomended/acceptable to
> >> "hold" the kernel before schedule() is/must be called? 1*HZ?
> >
> >Definitely less. A few milliseconds at most. Use kernel timers for
> >anything longer than 10ms.
>
>
> I'm doing some special downloading using the parport that takes
> totally approx. 1-2 seconds. Of course I can't lock the whole kernel
> throughout this download. To remedy this, I've made a counter, which
> calls interruptable_sleep_on() after approx. 1 ms in this loop. Is
> there any ways to automate this? I.e. I call a function before I enter
> this loop that sais: "It's OK to switch process/context when
> appropriate", so I don't have to worry about locking the whole kernel.
>
>
> Regards,
> Svein E. Seldal
>
>
>
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