Re: [patch] enabling APIC and NMI watchdog on UP systems

From: John Levon (moz@compsoc.man.ac.uk)
Date: Fri Sep 29 2000 - 05:58:47 EST


On Fri, 29 Sep 2000, Ingo Molnar wrote:

> that having all said, i'm not against a generic, nonpriviledged (kernel
> based) performance counter API within the kernel (if there is demand), and
> such an API should of course have close control over the contents of the
> performance counter registers, and in this case the NMI oopser has to
> cooperate. Something like doing per-process performance monitoring and
> potentially switching the MSRs on task-switch. But as far as i've seen,
> most people who want to have that kind of finegrained information about
> their system have no problem doing these things as root, and this is a
> much simpler implementation.
>
> Ingo

Of course Mikael Petersson's perfctr patch has been providing such for a
while now, and many people use it. My forthcoming profiler makes use the
counters in a different way, but as long as such an API is clean enough to
allow the various different uses w/o hacky patches I think this would be a
great idea.

prumpf has been talking about using some counter information for
scheduling/VM purposes as well ...

thanks
john

-- 
"The words CON and NUL
Are reserved by the system.
Don't ask; they just are."

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Sep 30 2000 - 21:00:24 EST