Re: [RFC PATCH] perf: Provide status of known PMUs

From: Ingo Molnar
Date: Thu Jul 09 2015 - 05:27:13 EST



* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Thu, Jul 09, 2015 at 10:48:00AM +0300, Adrian Hunter wrote:
>
> > Known PMUs may not be present for various reasons. Provide a way for the user
> > to know what the reason is.
>
> Not a bad idea, but I do wonder where we should draw the line on what is
> 'known'. The patch as proposed will have bts/pt listed as 'known' for every arch
> out there.
>
> By that logic, x86 should list the ppc/sparc/mips/arm/etc.. PMUs as known and
> wrong_arch too, which might be a tad excessive.

Absolutely x86 should list them as well - from a user POV arch dependent tooling
sucks in general. There's nothing more annoying than trying to figure out why a
particular tool does not work.

If memory usage becomes any concern in the future we can list them in a bit more
compressed form.

Thanks,

Ingo
--
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/