pmc soft

[Fabien Thomas]

Hi,

For those interested you can find a first usable version for i386 of PMC SOFT.
The goal is to add software PMC that can help to understand a workload.

Two interesting event:

SOFT-CLOCK can replace instructions sampling on host without PMC.
SOFT if compiled with KDTRACE_SOFTPMC expose all existing static probe of KDTRACE.

Adding new event is easy with two macro like for KDTRACE.

Some part need to be polished (small trap frame, free event) but it is in overall good shape.
Feel free to give your feedback.

http://people.freebsd.org/~fabient/patch-pmcsoft-20100321

Regards,
Fabien