Re: [PATCH 1/1] perf tools: Add missing user space support forconfig1/config2

From: Ingo Molnar
Date: Wed Apr 27 2011 - 02:44:14 EST



* Vince Weaver <vweaver1@xxxxxxxxxxxx> wrote:

> On Tue, 26 Apr 2011, Peter Zijlstra wrote:
>
> > > That's why people use libpfm4. or PAPI. And they do.
> >
> > And how is typing in hex numbers different from typing in model specific
> > event names?
>
> Reall... quick, tell me what event 0x53cf28 corresponds to on a core2.
>
> Now if I said L2_IFETCH:BOTH_CORES you know several things about what it is.

Erm, that assumes you already know that magic incantation. Most of the users
who want to do measurements and profiling do not know that. So there's little
difference between:

- someone shows them the 0x53cf28 magic code
- someone shows them the L2_IFETCH:BOTH_CORES magic symbol

So you while hexa values have like 10% utility, the stupid, vendor-specific
event names you are pushing here have like 15% utility.

In perf we are aiming for 100% utility, where if someone knows something about
CPUs and can type 'cycles', 'instructions' or 'branches', will get the obvious
result.

This is not a difficult usability concept really.

Thanks,

Ingo
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