linux-kernel - Re: [PATCH 13/32] x86,fs/resctrl: Add an architectural hook called for first mount

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Message-ID: <f3a5f539-0843-4643-9b52-8bb7315441ed@intel.com>
Date: Fri, 9 Jan 2026 07:28:25 -0800
From: Reinette Chatre <reinette.chatre@...el.com>
To: Tony Luck <tony.luck@...el.com>, Borislav Petkov <bp@...en8.de>
CC: 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>, <x86@...nel.org>, <linux-kernel@...r.kernel.org>,
	<patches@...ts.linux.dev>
Subject: Re: [PATCH 13/32] x86,fs/resctrl: Add an architectural hook called
 for first mount

Hi Tony,

On 1/8/26 9:42 AM, Tony Luck wrote:
> Enumeration of Intel telemetry events is an asynchronous process involving
> several mutually dependent drivers added as auxiliary devices during
> the device_initcall() phase of Linux boot. The process finishes after
> the probe functions of these drivers completes. But this happens after
> resctrl_arch_late_init() is executed.
> 
> Tracing the enumeration process shows that it does complete a full seven
> seconds before the earliest possible mount of the resctrl file system (when
> included in /etc/fstab for automatic mount by systemd).
> 
> Add a hook at the beginning of the mount code that will be used to check
> for telemetry events and initialize if any are found.
> 
> The hook is only called on the first mount of the resctrl file system as
> that is all that is needed for telemetry enumeration.

Needs imperative. "Only call the hook on the first mount ..."?
Although, to help with brevity, the last three sentences could be merged. For example:

	Add a hook for use by telemetry event enumeration and initialization and
	run it once at the beginning of resctrl mount without any locks held.
	Architecture is responsible for any required locking.

> 
> resctrl filesystem calls the hook with no locks held. Architecture code is
> responsible for any required locking.
> 
> Signed-off-by: Tony Luck <tony.luck@...el.com>
> ---

| Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>

Reinette