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

[Peter Zijlstra]

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.

Can we limit it to PMUs for which we've (attempted to) load the drivers?
That would obviously make a few of your status bits redundant, but then
you've not explained why we're interested in it.

> 	Supported
> 	Driver error
> 	Driver not loaded
> 	Not supported by hardware
> 	Wrong vendor
> 	Unknown status

There would work.

> 	Driver not in kernel config
> 	Not supported by kernel
> 	Wrong architecture

These will be hard, for if we don't load the driver we don't 'know' of
them.
--
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/