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Sat, 11 Oct 2025 01:18:41 +0000 From: Aaron Tomlin To: gregkh@linuxfoundation.org, nathan@kernel.org, rafael@kernel.org, dakr@kernel.org Cc: riel@surriel.com, frederic@kernel.org, atomlin@atomlin.com, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/2] sysfs/cpu: Use DEVICE_ATTR_RO for nohz_full attribute Date: Fri, 10 Oct 2025 21:18:29 -0400 Message-ID: <20251011011830.6670-2-atomlin@atomlin.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20251011011830.6670-1-atomlin@atomlin.com> References: <20251011011830.6670-1-atomlin@atomlin.com> Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: MN0P222CA0019.NAMP222.PROD.OUTLOOK.COM (2603:10b6:208:531::25) To CWLP123MB3523.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:70::10) 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: CWLP123MB3523:EE_|LO0P123MB7766:EE_ X-MS-Office365-Filtering-Correlation-Id: 91a3619f-c34f-4b35-7c39-08de08641cb7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014; 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charset="utf-8" The /sys/devices/system/cpu/nohz_full file is a read-only attribute that reports the CPUs configured for tickless operation (CONFIG_NO_HZ_FULL=3Dy). The current definition uses the generic DEVICE_ATTR macro, which unnecessarily requires specifying the file mode (0444) and a NULL store operation pointer. This patch converts the definition to use the dedicated DEVICE_ATTR_RO macro. This correctly expresses the read-only nature of the attribute, removes the redundant mode field, and simplifies the code. As a related cleanup, rename the show function from print_cpus_nohz_full() to the standard nohz_full_show() for consistency with common sysfs attribute naming conventions. Signed-off-by: Aaron Tomlin --- drivers/base/cpu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index fa0a2eef93ac..c792ec66462d 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -301,12 +301,13 @@ static ssize_t print_cpus_isolated(struct device *dev, static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL); =20 #ifdef CONFIG_NO_HZ_FULL -static ssize_t print_cpus_nohz_full(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t nohz_full_show(struct device *dev, + struct device_attribute *attr, + char *buf) { return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask)); } -static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL); +static DEVICE_ATTR_RO(nohz_full); #endif =20 #ifdef CONFIG_CRASH_HOTPLUG --=20 2.49.0