Re: [discuss] Re: 2.6.19-rc5: known regressions (v3)

[Andi Kleen]

> What other purposes do you see the performance counters useful for? 

Export one to user space as a cycle counter for benchmarking. RDTSC doesn't 
do this job anymore.

> To collect information on process characteristics so they can be scheduled more efficiently?

That might happen at some point in the future, but i would expect
us to wait for CPUs with more performance counters first.

> Is this going to require sharing the nmi interrupt and knowing which perfcounter 
> register triggered the interrupt to get the correct action?  Currently the 
> oprofile interrupt handler assumes any performance monitoring counter it sees 
> overflowing is something it should count.

Yes. That needs to be fixed.

-Andi

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