Re: [generalized cache events] Re: [PATCH 1/1] perf tools: Addmissing user space support for config1/config2

From: Ingo Molnar
Date: Fri Apr 22 2011 - 15:57:42 EST



* Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:

> > Once you have clear and precise definition, then we can look at the actual
> > events and figure out a mapping.
>
> It's unclear this can be even done. Linux runs on a wide variety of micro
> architectures, with all kinds of cache architectures.
>
> Micro architectures are so different. I suspect a "generic" definition would
> need to be so vague as to be useless.

Not really. I gave a very specific example which solved a common and real
problem, using L1-loads and L1-load-misses events.

> This in general seems to be the problem of the current cache events.
>
> Overall for any interesting analysis you need to go CPU specific. Abstracted
> performance analysis is a contradiction in terms.

Nothing of what i did in that example was CPU or microarchitecture specific.

Really, you are making this more complex than it really is. Just check the
cache profiling example i gave, it works just fine today.

Thanks,

Ingo
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