[Valgrind-users] cachegrind on a kernel driver

[Jim C. <jim...@gm...>]

Over on lm-sensors, Im advocating the use of 2D-callbacks (sysfs),
which allows the consolidation of multiple (1D) callbacks,
thus reducing text-size.  Ive been asked to 'prove' its a win.

Setting aside the idea that this is not a high-traffic interface
(voltages & temps for system health monitoring), how can I go about it ?

Im aware that valgrind has been used on a UML kernel, but the valgrind 
ML threads
arent particularly helpful (Ive never used UML in any way, so its hard 
to tell).
Running a Xen-guest also occurred to me, but 'Xen' has zero hits
on gmane.comp.debugging.valgrind.

Are UML or Xen my best bet for getting some cachegrind data on a kernel 
driver ?
or is there another way I havent thought of ?
Oprofile has occurred to me, but Im a newbie there too.  While it might 
show some
total time spent in the callbacks, it seems (apriori) unlikely to just 
tell me the cache usage
of a handful of routines (it does have filtering, but I think thats by 
application,
a couple functions in a kernel driver is a very different problem).

any hints welcome
tia