From: Reinette Chatre <reinette.chatre@intel.com>
To: Babu Moger <babu.moger@amd.com>, <corbet@lwn.net>,
<tony.luck@intel.com>, <Dave.Martin@arm.com>,
<james.morse@arm.com>, <tglx@kernel.org>, <bp@alien8.de>,
<dave.hansen@linux.intel.com>
Cc: <skhan@linuxfoundation.org>, <x86@kernel.org>, <mingo@redhat.com>,
<hpa@zytor.com>, <akpm@linux-foundation.org>,
<rdunlap@infradead.org>, <pawan.kumar.gupta@linux.intel.com>,
<feng.tang@linux.alibaba.com>, <dapeng1.mi@linux.intel.com>,
<kees@kernel.org>, <elver@google.com>, <lirongqing@baidu.com>,
<paulmck@kernel.org>, <bhelgaas@google.com>, <seanjc@google.com>,
<alexandre.chartre@oracle.com>, <yazen.ghannam@amd.com>,
<peterz@infradead.org>, <chang.seok.bae@intel.com>,
<kim.phillips@amd.com>, <xin@zytor.com>, <naveen@kernel.org>,
<thomas.lendacky@amd.com>, <linux-doc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <eranian@google.com>,
<peternewman@google.com>
Subject: Re: [PATCH v3 06/12] fs/resctrl: Initialize the global kernel-mode policy at subsystem init
Date: Mon, 22 Jun 2026 09:21:49 -0700 [thread overview]
Message-ID: <737a4228-52fb-4583-ac64-8efe79c107e6@intel.com> (raw)
In-Reply-To: <416d685f-9e76-415a-bbb0-fc89f87827d9@amd.com>
Hi Babu,
On 6/18/26 10:14 AM, Babu Moger wrote:
> On 6/16/26 18:36, Reinette Chatre wrote:
>> On 4/30/26 4:24 PM, Babu Moger wrote:
>>
>>> - calls resctrl_arch_get_kmode_support() so each architecture ORs
>>> BIT(<mode>) into kmode for the policies its hardware supports
>>> (on x86, AMD PLZA contributes the two global-assign modes).
>>>
>>> resctrl_kmode_init() runs from resctrl_init() once the default group
>>
>> resctrl_kmode_init() can be dropped after changes described in response
>> to previous patch. Apart from no longer being necessary I also find that
>> having the kernel mode fully initialized *before* the hotplug handlers run
>> to be simpler.
>
> That means resctrl_set_kmode_support() will be called from the architecture layer, likely from core.c within get_rdt_alloc_resources().
>
> The resctrl_set_kmode_support() handler would need to initialize both the default mode and all supported modes.
I see this differently. Since resctrl_set_kmode_support() is optional for an architecture
resctrl fs can just statically initialize the defaults. resctrl_set_kmode_support() would
expand the defaults to also accommodate what the architecture supports.
Reinette
next prev parent reply other threads:[~2026-06-22 16:22 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-30 23:24 [PATCH v3 00/12] [PATCH v3 00/12] x86/resctrl: Add kernel-mode (e.g., PLZA) support to the resctrl subsystem Babu Moger
2026-04-30 23:24 ` [PATCH v3 01/12] x86/resctrl: Support Privilege-Level Zero Association (PLZA) Babu Moger
2026-06-11 23:23 ` Reinette Chatre
2026-06-12 16:56 ` Moger, Babu
2026-06-12 17:00 ` Moger, Babu
2026-06-17 0:00 ` Reinette Chatre
2026-06-17 16:28 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 02/12] x86/resctrl: Add data structures and definitions for PLZA configuration Babu Moger
2026-06-11 23:40 ` Reinette Chatre
2026-06-12 15:40 ` Luck, Tony
2026-06-12 17:46 ` Moger, Babu
2026-06-12 17:32 ` Moger, Babu
2026-06-12 17:49 ` Moger, Babu
2026-04-30 23:24 ` [PATCH v3 03/12] fs/resctrl: Add kernel mode (kmode) data structures and arch hook Babu Moger
2026-06-16 23:30 ` Reinette Chatre
2026-06-17 19:36 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 04/12] x86,fs/resctrl: Program PLZA through kmode arch hooks Babu Moger
2026-05-19 20:59 ` Luck, Tony
2026-05-20 17:49 ` Babu Moger
2026-05-20 22:16 ` Luck, Tony
2026-05-20 23:09 ` Moger, Babu
2026-06-11 11:44 ` Peter Newman
2026-06-11 14:46 ` Babu Moger
2026-06-16 23:33 ` Reinette Chatre
2026-06-17 23:15 ` Moger, Babu
2026-04-30 23:24 ` [PATCH v3 05/12] x86/resctrl: Initialize supported kernel modes for PLZA Babu Moger
2026-06-16 23:35 ` Reinette Chatre
2026-06-18 16:20 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 06/12] fs/resctrl: Initialize the global kernel-mode policy at subsystem init Babu Moger
2026-06-16 23:36 ` Reinette Chatre
2026-06-18 17:14 ` Babu Moger
2026-06-22 16:21 ` Reinette Chatre [this message]
2026-06-22 16:38 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 07/12] fs/resctrl: Add info/kernel_mode for kernel-mode policy introspection Babu Moger
2026-06-16 23:38 ` Reinette Chatre
2026-06-18 19:16 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 08/12] fs/resctrl: Make info/kernel_mode writable and identify the bound group Babu Moger
2026-06-16 23:42 ` Reinette Chatre
2026-06-19 1:29 ` Babu Moger
2026-06-22 16:47 ` Reinette Chatre
2026-06-22 19:03 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 09/12] fs/resctrl: Reset kernel-mode binding when its rdtgroup goes away Babu Moger
2026-06-16 23:42 ` Reinette Chatre
2026-06-19 20:22 ` Babu Moger
2026-04-30 23:24 ` [PATCH v3 10/12] fs/resctrl: Expose kmode_cpus / kmode_cpus_list per rdtgroup Babu Moger
2026-04-30 23:24 ` [PATCH v3 11/12] resctrl: Hide kmode_cpus[_list] on groups not bound to kernel-mode Babu Moger
2026-04-30 23:24 ` [PATCH v3 12/12] fs/resctrl: Allow user space to write kmode_cpus / kmode_cpus_list Babu Moger
2026-06-11 21:53 ` [PATCH v3 00/12] [PATCH v3 00/12] x86/resctrl: Add kernel-mode (e.g., PLZA) support to the resctrl subsystem Reinette Chatre
2026-06-12 15:37 ` Moger, Babu
2026-06-17 4:34 ` Reinette Chatre
2026-06-17 15:56 ` Babu Moger
2026-06-17 17:33 ` Reinette Chatre
2026-06-17 19:55 ` Babu Moger
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