linux-kernel - Re: [PATCH v5 10/13] x86/process: Clear hardware feedback history for AMD processors

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Message-ID: <20241029194801.GAZyE78b5j1skQ0Kf_@fat_crate.local>
Date: Tue, 29 Oct 2024 20:48:01 +0100
From: Borislav Petkov <bp@...en8.de>
To: Mario Limonciello <mario.limonciello@....com>
Cc: Hans de Goede <hdegoede@...hat.com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	x86@...nel.org, "Gautham R . Shenoy" <gautham.shenoy@....com>,
	Perry Yuan <perry.yuan@....com>, linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org, linux-pm@...r.kernel.org,
	platform-driver-x86@...r.kernel.org,
	Shyam Sundar S K <Shyam-sundar.S-k@....com>
Subject: Re: [PATCH v5 10/13] x86/process: Clear hardware feedback history
 for AMD processors

On Sun, Oct 27, 2024 at 09:02:48PM -0500, Mario Limonciello wrote:
> +__always_inline void reset_hardware_history_hetero(void)
> +{
> +	if (static_branch_unlikely(&hardware_history_features))
> +		wrmsrl(AMD_WORKLOAD_HRST, 0x1);

Get rid of all of the other crap - the static key and that
reset_hardware_history_hetero() silly thing and do

	/* Reset hw history on AMD CPUs */
	if (cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS))
		wrmsrl(AMD_WORKLOAD_HRST, 0x1);

in __switch_to().

Nothing else.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette