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Message-ID: <b234c859-75f4-ca3d-eee6-17af7680365d@arm.com>
Date:   Wed, 12 Jul 2023 08:12:44 +0530
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Subject: Re: [PATCH V13 - RESEND 06/10] arm64/perf: Enable branch stack events
 via FEAT_BRBE
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To:     Randy Dunlap <rdunlap@infradead.org>,
        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>
 <cde1fd99-04ae-f604-a5d0-5af3ddf57f7d@infradead.org>
From:   Anshuman Khandual <anshuman.khandual@arm.com>
In-Reply-To: <cde1fd99-04ae-f604-a5d0-5af3ddf57f7d@infradead.org>
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On 7/12/23 00:56, Randy Dunlap wrote:
> 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

Agreed, will change.

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