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Wed, 19 Aug 2026 23:08:03 +0000 Message-ID: Date: Wed, 19 Aug 2026 16:08:02 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 7/9] fs/resctrl: Do not invoke smp_processor_id() in preemptible context To: Chen Yu , CC: , , , , , , , , , References: Content-Language: en-US From: Reinette Chatre In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR03CA0347.namprd03.prod.outlook.com (2603:10b6:303:dc::22) To SJ2PR11MB8370.namprd11.prod.outlook.com (2603:10b6:a03:540::20) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ2PR11MB8370:EE_|DS0PR11MB7901:EE_ X-MS-Office365-Filtering-Correlation-Id: 6f93a9f2-999a-4a79-0511-08defe46b8f5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|7416014|376014|1800799024|6133799003|56012099006|10067099003|4143699003|11063799006|22082099003|18002099003; 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Please let the context describe what the *current* code does. This changelog describes context that does not exist (yet) and then presents the change in this patch as a bugfix. This is not accurate and misrepresents this change. > > __l3_mon_event_count() calls smp_processor_id() to find the CPU to read > from. For an any_cpu event that lookup is unsafe: > the code runs in preemptible task context, so smp_processor_id() emits a > debug warning. > > Skip the current-CPU lookup when an event's any_cpu flag is set, events with > this flag do not require execution on a specific CPU. For legacy MSR-based > access, update rmid_read::err if the reading of the event was dispatched to > a wrong CPU, according to the change at: > https://lore.kernel.org/lkml/6b3c66a49788828bd8c04a6911bd74c91ccd56f3.1782857711.git.reinette.chatre@intel.com/ This has been merged now so it should not be necessary to call this out, at least in this format > > Signed-off-by: Tony Luck > Signed-off-by: Chen Yu > Tested-by: Hongyu Ning > --- Reinette