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Tue, 7 Oct 2025 01:25:08 +0000 From: Aaron Tomlin To: gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org Cc: riel@surriel.com, frederic@kernel.org, atomlin@atomlin.com, linux-kernel@vger.kernel.org Subject: [PATCH v2 0/1] tick/nohz: avoid showing '(null)' if nohz_full= not set Date: Mon, 6 Oct 2025 21:25:03 -0400 Message-ID: <20251007012504.16118-1-atomlin@atomlin.com> X-Mailer: git-send-email 2.49.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: MN2PR15CA0027.namprd15.prod.outlook.com (2603:10b6:208:1b4::40) 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_|LOBP123MB8319:EE_ X-MS-Office365-Filtering-Correlation-Id: e2d8b398-282a-4cfd-1abf-08de05405a3b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; 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Memory is only allocated to the cpumask data structure, when Linux kernel boot-time parameter "nohz_full=" is correctly specified (see tick_nohz_full_setup() and housekeeping_setup()). If "nohz_full=" is not set and an attempt is made to read /sys/devices/system/cpu/nohz_full, '(null)' can be displayed: ❯ cat /sys/devices/system/cpu/nohz_full (null) This patch changes the output to print a newline (or 0x0A) instead of '(null)', making it consistent with print_cpus_isolated() behaviour. Changes since v1 [1]: - Refactor to use an if statement (Greg KH) [1]: https://lore.kernel.org/lkml/20251006005824.76187-1-atomlin@atomlin.com/ Aaron Tomlin (1): tick/nohz: avoid showing '(null)' if nohz_full= not set drivers/base/cpu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 2.49.0