linux-kernel - Re: [PATCH v8 23/32] x86/resctrl: Handle domain creation/deletion for RDT_RESOURCE_PERF

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Message-ID: <062ca116-7e0c-4d64-abf0-d1c73d23362b@intel.com>
Date: Thu, 14 Aug 2025 14:51:32 -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 v8 23/32] x86/resctrl: Handle domain creation/deletion for
 RDT_RESOURCE_PERF_PKG

Hi Tony,

On 8/11/25 11:16 AM, Tony Luck wrote:
> The L3 resource has several requirements for domains. There are structures

"There are structures" -> "There are per domain structures ..."?
(to help connect with new domain structure later)

> that hold the 64-bit values of counters, and elements to keep track of
> the overflow and limbo threads.
> 
> None of these are needed for the PERF_PKG resource. The hardware counters
> are wide enough that they do not wrap around for decades.
> 
> Define a new rdt_perf_pkg_mon_domain structure which just consists of
> the standard rdt_domain_hdr to keep track of domain id and CPU mask.
> 
> Add a case RDT_RESOURCE_PERF_PKG to domain_add_cpu_mon() to call
> intel_aet_setup_mon_domain() to allocate and initialize the
> rdt_perf_pkg_mon_domain structure.
> 
> Also add a case to domain_remove_cpu_mon() cleanup when the last

"cleanup" -" to clean up" ?

Regarding the "Add a case" usage ... you need not document the actual
code changes in such detail, that can be seen from the patch. Just describing
what the patch does on high level is sufficient.
For example,
	Support the PERF_PKG resource in the CPU online/offline	handlers.
	Allocate and initialize the rdt_perf_pkg_mon_domain structure
	when the first CPU of a domain comes online and do necessary
	cleanup when the last CPU of a domain goes offline. 

> CPU of a domain is removed.
> 
> Signed-off-by: Tony Luck <tony.luck@...el.com>
> ---

Reinette