hyper threading

[Jarek]

Hi
Im looking informations about writing drivers under
procesors with HT technology. The drivers written
in 'classical way' doesnt work.
I mean: I have prototype pci card with some resouces, I
wrote driver, witch works with P4 without HT and doesnt
works with HT. Im looking some informations, articles,
manuals how to write drivers, including irq, ports io,
memory, witch will be working under hyper threading.
You know where I should looking for?
best regards

 

[Gary G. Little]

Hyperthreading is no different than SMP, with 2 or 4 or 8 processors on the
mother board. The primary difference is you have a single piece of silicone
that thinks it's two. You then write your driver to be multi-processor safe,
and not hyper threading safe. My guess is that you don't understand how
multiprocessor programming is different and therefore are blaming HT for
crashing when you are not serializing and synchronizing access to critical
data. You need to know how to access data that may be accessed by both
processors simultaneously, and how to serialize access to it. Look up
spinlocks and pay particular attention to KeSynchronizeExecution.