linux-kernel - Re: [PATCH v11 16/31] x86,fs/resctrl: Add architectural event pointer

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Message-ID: <2ec8e10d-fffb-403b-bd86-722a6520c1ae@intel.com>
Date: Fri, 3 Oct 2025 16:38:48 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: Tony Luck <tony.luck@...el.com>, Fenghua Yu <fenghuay@...dia.com>, "Maciej
 Wieczor-Retman" <maciej.wieczor-retman@...el.com>, Peter Newman
	<peternewman@...gle.com>, James Morse <james.morse@....com>, Babu Moger
	<babu.moger@....com>, Drew Fustini <dfustini@...libre.com>, Dave Martin
	<Dave.Martin@....com>, Chen Yu <yu.c.chen@...el.com>
CC: <x86@...nel.org>, <linux-kernel@...r.kernel.org>,
	<patches@...ts.linux.dev>
Subject: Re: [PATCH v11 16/31] x86,fs/resctrl: Add architectural event pointer

Hi Tony,

On 9/25/25 1:03 PM, Tony Luck wrote:
> The resctrl file system layer passes the domain, RMID, and event id to
> resctrl_arch_rmid_read() to fetch an event counter.
> 
> Fetching a telemetry event counter requires additional information that
> is private to the architecture, for example, the offset into MMIO space
> from where counter should be read.
> 
> Add mon_evt::arch_priv void pointer. Architecture code can initialize
> this when marking each event enabled.
> 
> File system code passes this pointer to resctrl_arch_rmid_read().

A suggestion to avoid describing code that can be seen from the patch:

	The resctrl file system layer passes the domain, RMID, and event id to
	the architecture to fetch an event counter.

	Fetching a telemetry event counter requires additional information that
	is private to the architecture, for example, the offset into MMIO space
	from where the counter should be read.

	Add mon_evt::arch_priv that architecture can use for any private          
	data related to the event. resctrl filesystem initializes mon_evt::arch_priv    
	when the architecture enables the event and passes it back to architecture      
	when needing to fetch an event counter.

> 
> Suggested-by: Reinette Chatre <reinette.chatre@...el.com>
> Signed-off-by: Tony Luck <tony.luck@...el.com>
> ---

Reinette