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

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Message-ID: <20201021223932.GP466880@tassilo.jf.intel.com>
Date:   Wed, 21 Oct 2020 15:39:32 -0700
From:   Andi Kleen <ak@...ux.intel.com>
To:     Stephane Eranian <eranian@...gle.com>
Cc:     linux-kernel@...r.kernel.org, kan.liang@...el.com,
        jolsa@...hat.com, peterz@...radead.org, mingo@...e.hu,
        irogers@...gle.com, namhyung@...nel.org
Subject: Re: [PATCH] perf/x86/intel: make anythread filter support conditional

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@...ux.intel.com>

-Andi