On Wed, 25 Apr 2007 00:13:04 +0200
Martin Husemann <martin@duskware.de> wrote:

> What would be a reasonable kqueue/kevent interface for this API?
> We should be able to avoid userland polling for sensor data, as the
> transfers now get pretty expensive.

I wanted to know why aiboost and other drivers were so expensive
recieving its values via gtredata and yesterday I did find a bug
in most drivers.

It's documented in PR kern/36226. I'm doing tests with aiboost(4) and
lm(4) on the same machine (aiboost is an ACPI wrapper that retrieves
the values from the chip, a Winbond W83627DHG in my case).

After fixing this bug, running an endless loop retrieving values
from the driver no longer results in any cpu time used.

I've used:

$ while true; do ./prop; done

prop calls prop_dictionary_recv_ioctl with ENVSYS_GTREDATA, and
uses prop_dictionary_externalize to print the XML output.

CPU Usage is now 0, YAY!

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