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Message-ID: <cde1fd99-04ae-f604-a5d0-5af3ddf57f7d@infradead.org>
Date:   Tue, 11 Jul 2023 12:26:11 -0700
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Subject: Re: [PATCH V13 - RESEND 06/10] arm64/perf: Enable branch stack events
 via FEAT_BRBE
Content-Language: en-US
To:     Anshuman Khandual <anshuman.khandual@arm.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com
Cc:     Mark Brown <broonie@kernel.org>, James Clark <james.clark@arm.com>,
        Rob Herring <robh@kernel.org>, Marc Zyngier <maz@kernel.org>,
        Suzuki Poulose <suzuki.poulose@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        linux-perf-users@vger.kernel.org
References: <20230711082455.215983-1-anshuman.khandual@arm.com>
 <20230711082455.215983-7-anshuman.khandual@arm.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230711082455.215983-7-anshuman.khandual@arm.com>
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Hi--

On 7/11/23 01:24, Anshuman Khandual wrote:
> diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
> index f4572a5cca72..7c8448051741 100644
> --- a/drivers/perf/Kconfig
> +++ b/drivers/perf/Kconfig
> @@ -180,6 +180,17 @@ config ARM_SPE_PMU
>  	  Extension, which provides periodic sampling of operations in
>  	  the CPU pipeline and reports this via the perf AUX interface.
>  
> +config ARM64_BRBE
> +	bool "Enable support for Branch Record Buffer Extension (BRBE)"
> +	depends on PERF_EVENTS && ARM64 && ARM_PMU
> +	default y
> +	help
> +	  Enable perf support for Branch Record Buffer Extension (BRBE) which
> +	  records all branches taken in an execution path. This supports some
> +	  branch types and privilege based filtering. It captured additional

preferably:
	                                                 captures

> +	  relevant information such as cycle count, misprediction and branch
> +	  type, branch privilege level etc.

-- 
~Randy