Messages in this thread | | | Date | Wed, 11 Nov 1998 10:24:02 +0100 | From | Alessandro Rubini <> | Subject | Re: Question about linux drivers |
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Hello.
> 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 and other hackers asked a major number for every thing we write a driver for, Linux will already have a 64-bit kdev_t :)
> 2. Ditto, but applying to ioctl magic numbers?
You're on you own. Every device declares its headers. Once again, if you want some advice, ask for it.
> 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.
Best /alessandro -- __ o Tu vuo` fa` l'americano: sient'a me chi t'o fa fa`. _`\<, (Renato Carosone) __( )/( )__ alessandro.rubini@linux.it +39-0382-529554
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