Re: [PATCH] perf/x86/intel: make anythread filter support conditional

From: Andi Kleen
Date: Wed Oct 21 2020 - 18:39:37 EST


On Wed, Oct 21, 2020 at 02:16:12PM -0700, Stephane Eranian wrote:
> Starting with Arch Perfmon v5, the anythread filter on generic counters may be
> deprecated. The current kernel was exporting the any filter without checking.
> On Icelake, it means you could do cpu/event=0x3c,any/ even though the filter
> does not exist. This patch corrects the problem by relying on the CPUID 0xa leaf
> function to determine if anythread is supported or not as described in the
> Intel SDM Vol3b 18.2.5.1 AnyThread Deprecation section.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

-Andi