MSR module

Lorenzo M. Catucci (lorenzo@argon.roma2.infn.it)
Fri, 14 Nov 1997 09:49:21 +0100 (CET)


Two comments about Stephan's module:

at first, i think it is really useful (from the specs), and I'd really
like to see it upgraded to work with 2.0.3[12], or to have an explicit
acknoledgment of its working well with latest ``stable'' kernels...
As a matter of fact, I'm still resisting to the `thirties', and running a
2.0.29 kernel on my `production' system, even though I'm preparing to run
.32 to have the lock prefix bug fixed.

Now, the second comment:

> c) /proc/sys + sysctl
>
> Would this do any good? You could probably write to a file to
> select the MSR register/performance counter and then read from
> it. I'd love to do it that way, but access would be restricted
> to root. Is that okay?

Please, no: I think there should be some way to have those read by normal
users, even if there could be some need for an explicit root's
authorization, if the access could be granted only to a devel group, to
which the willing profiler should be added, and to which he should change
before using the performance registers... even though I fear this could
stop the upgrade to a better gprof I envision...