linux-kernel - Re: [PATCH v16 33/34] x86/resctrl: Configure mbm

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Message-ID: <bb734538-4280-4748-9192-5bfa5ca8c8ab@intel.com>
Date: Wed, 30 Jul 2025 13:11:36 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: Babu Moger <babu.moger@....com>, <corbet@....net>, <tony.luck@...el.com>,
	<james.morse@....com>, <tglx@...utronix.de>, <mingo@...hat.com>,
	<bp@...en8.de>, <dave.hansen@...ux.intel.com>
CC: <Dave.Martin@....com>, <x86@...nel.org>, <hpa@...or.com>,
	<akpm@...ux-foundation.org>, <paulmck@...nel.org>, <rostedt@...dmis.org>,
	<Neeraj.Upadhyay@....com>, <david@...hat.com>, <arnd@...db.de>,
	<fvdl@...gle.com>, <seanjc@...gle.com>, <jpoimboe@...nel.org>,
	<pawan.kumar.gupta@...ux.intel.com>, <xin@...or.com>,
	<manali.shukla@....com>, <tao1.su@...ux.intel.com>, <sohil.mehta@...el.com>,
	<kai.huang@...el.com>, <xiaoyao.li@...el.com>, <peterz@...radead.org>,
	<xin3.li@...el.com>, <kan.liang@...ux.intel.com>,
	<mario.limonciello@....com>, <thomas.lendacky@....com>, <perry.yuan@....com>,
	<gautham.shenoy@....com>, <chang.seok.bae@...el.com>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<peternewman@...gle.com>, <eranian@...gle.com>
Subject: Re: [PATCH v16 33/34] x86/resctrl: Configure mbm_event mode if
 supported

Hi Babu,

On 7/25/25 11:29 AM, Babu Moger wrote:
> Configure mbm_event mode on AMD platforms. On AMD platforms, it is
> recommended to use the mbm_event mode, if supported, to prevent the
> hardware from resetting counters between reads. This can result in
> misleading values or display "Unavailable" if no counter is assigned
> to the event.
> 
> The mbm_event mode, referred to as ABMC (Assignable Bandwidth Monitoring
> Counters) on AMD, is enabled by default when supported by the system.

needs imperative

> 
> Update ABMC across all logical processors within the resctrl domain to
> ensure proper functionality.
> 
> Signed-off-by: Babu Moger <babu.moger@....com>
> ---

Patch looks good.

Reinette