Re: [PATCH] perf/x86: Bump INTEL_PMC_MAX_FIXED for Icelake

From: Peter Zijlstra
Date: Tue Nov 20 2018 - 07:51:08 EST


On Wed, Nov 14, 2018 at 02:25:18PM +0000, Chris Wilson wrote:

> I am not aware of what the consequences are of bumping this limit, so
> please take the patch with a pinch of salt and more of a heads up!

Yeah, this will only make your warning go away, but is not suitable for
upstream. The upstream icelake enablement would be a much larger patch
that actually enables the new PMU features.

So I suggest you carry this in your CI tree until the icelake patches
are allowed to go public.

> diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
> index 8bdf74902293..ab4cf7c12c40 100644
> --- a/arch/x86/include/asm/perf_event.h
> +++ b/arch/x86/include/asm/perf_event.h
> @@ -7,7 +7,7 @@
> */
>
> #define INTEL_PMC_MAX_GENERIC 32
> -#define INTEL_PMC_MAX_FIXED 3
> +#define INTEL_PMC_MAX_FIXED 4
> #define INTEL_PMC_IDX_FIXED 32
>
> #define X86_PMC_IDX_MAX 64
> --
> 2.19.1
>