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Message-ID: <04bc4e49-8633-63db-5c13-12953f3349bc@arm.com>
Date:   Tue, 25 Jul 2023 10:13:15 +0530
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Subject: Re: [PATCH v2 4/4] perf: Remove unused
 PERF_PMU_CAP_HETEROGENEOUS_CPUS capability
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To:     James Clark <james.clark@arm.com>,
        linux-perf-users@vger.kernel.org, irogers@google.com,
        will@kernel.org
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
References: <20230724134500.970496-1-james.clark@arm.com>
 <20230724134500.970496-5-james.clark@arm.com>
From:   Anshuman Khandual <anshuman.khandual@arm.com>
In-Reply-To: <20230724134500.970496-5-james.clark@arm.com>
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On 7/24/23 19:14, James Clark wrote:
> Since commit bd2756811766 ("perf: Rewrite core context handling") the
> relationship between perf_event_context and PMUs has changed so that
> the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally
> silenced no longer exists.
> 
> Remove the capability to avoid confusion that it actually influences
> any perf core behavior and shift down the following capability bits to
> fill in the unused space. This change should be a no-op.
> 
> Acked-by: Ian Rogers <irogers@google.com>
> Signed-off-by: James Clark <james.clark@arm.com>

Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>

> ---
>  include/linux/perf_event.h | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 2166a69e3bf2..c617badd1e76 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -288,10 +288,9 @@ struct perf_event_pmu_context;
>  #define PERF_PMU_CAP_EXTENDED_REGS		0x0008
>  #define PERF_PMU_CAP_EXCLUSIVE			0x0010
>  #define PERF_PMU_CAP_ITRACE			0x0020
> -#define PERF_PMU_CAP_HETEROGENEOUS_CPUS		0x0040
> -#define PERF_PMU_CAP_NO_EXCLUDE			0x0080
> -#define PERF_PMU_CAP_AUX_OUTPUT			0x0100
> -#define PERF_PMU_CAP_EXTENDED_HW_TYPE		0x0200
> +#define PERF_PMU_CAP_NO_EXCLUDE			0x0040
> +#define PERF_PMU_CAP_AUX_OUTPUT			0x0080
> +#define PERF_PMU_CAP_EXTENDED_HW_TYPE		0x0100
>  
>  struct perf_output_handle;
>