Re: [RFC 00/10] perf tools: Add support to reuse metric

[Michael Petlan]

On Fri, 26 Jun 2020, Andi Kleen wrote:
> > The name could be a metric or an event, the logic for each is quite
> 
> I would say collisions are unlikely. Event names follow quite structured
> patterns.

But across various architectures? I guess event names can be arbitrary.
In perftool-testsuite, I use the following regexp to match event names:
[\w\-\:\/_=,]+

> 
> > different. You could look up an event and when it fails assume it was
> > a metric, but I like the simplicity of this approach.
> 
> I don't think it's simpler for the user.
>
I think it should be clear at the user level whether they're using an event
or a metric (basically a couple of events together). I don't hiding too
much of details from users is any good.

> > Maybe this
> > change could be adopted more widely with something like "perf stat -e
> > metric:IPC -a -I 1000" rather than the current "perf stat -M IPC -a -I
> > 1000".
> 
> I thought about just adding metrics to -e, without metric: of course.
> 
> -Andi
> 
>