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Message-ID: <96f4cf1f-bd1e-ae5b-172b-fea572a32500@infradead.org>
Date:   Tue, 7 Jun 2022 07:40:42 -0700
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Subject: Re: [PATCH v5 5/6] x86: Add Kconfig/Makefile to build hardware
 prefetch control driver
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To:     Kohei Tarumizu <tarumizu.kohei@fujitsu.com>,
        catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, rafael@kernel.org, lenb@kernel.org,
        gregkh@linuxfoundation.org, mchehab+huawei@kernel.org,
        eugenis@google.com, tony.luck@intel.com, pcc@google.com,
        peterz@infradead.org, marcos@orca.pet, marcan@marcan.st,
        linus.walleij@linaro.org, nicolas.ferre@microchip.com,
        conor.dooley@microchip.com, arnd@arndb.de, ast@kernel.org,
        peter.chen@kernel.org, kuba@kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-acpi@vger.kernel.org
References: <20220607120530.2447112-1-tarumizu.kohei@fujitsu.com>
 <20220607120530.2447112-6-tarumizu.kohei@fujitsu.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20220607120530.2447112-6-tarumizu.kohei@fujitsu.com>
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On 6/7/22 05:05, Kohei Tarumizu wrote:
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 4bed3abf444d..3ee173483f9f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1359,6 +1359,23 @@ config X86_CPUID
>  	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
>  	  /dev/cpu/31/cpuid.
>  
> +config X86_HWPF_CONTROL
> +	tristate "x86 Hardware Prefetch Control support"
> +	depends on X86_64
> +	help
> +	  This provides a sysfs interface to control the Hardware Prefetch
> +	  behavior for X86.
> +
> +	  Some Intel processors have MSR 0x1a4 (MSR_MISC_FEATURE_CONTROL),
> +	  which can control the hardware prefech behavior. If the processor

	                                 prefetch

> +	  supports this, the module can be loaded with the name x86-pfctl.
> +
> +	  Depending on the characteristics of the application, this register
> +	  parameters improve or degrade performance.
> +
> +	  Please see Documentation/ABI/testing/sysfs-devices-system-cpu for
> +	  more information.
> +

-- 
~Randy