Re: Linux and real device drivers

Jes Sorensen (Jes.Sorensen@cern.ch)
21 Sep 1999 22:15:34 +0200


>>>>> "Bret" == Bret Indrelee <breti@bit3.com> writes:

Bret> Jes Sorensen asserts:
>> Yes, UDI also guarantees you a trendous overhead and almost
>> certainly lousy performance - last time I looked at the spec, about
>> a year ago, it certainly wasn't pretty.

Bret> If this isn't just a case of you spreading FUD, could you please
Bret> give some data to back up your claims?

Bret> To my knowledge, no one has run benchmarks against the current
Bret> UDI definition. The original prototype was a little bit slower,
Bret> but performance changes were made to minimize or eliminate these
Bret> areas.

Again, the last version of UDI I looked at was 0.80. Anyway, UDI means
going through indirect functions to simply read/write a device
register since you have no idea how a device is mapped in a certain
type of machine or operating system .... this alone should be enough
to prove my point.

Jes

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