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client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by SA2PEPF000015C6.mail.protection.outlook.com (10.167.241.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8655.12 via Frontend Transport; Sat, 12 Apr 2025 05:12:17 +0000 Received: from [10.252.90.31] (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Sat, 12 Apr 2025 00:12:13 -0500 Message-ID: <77f5e50c-ba52-42de-8668-e15660ba9eb3@amd.com> Date: Sat, 12 Apr 2025 10:42:04 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 5/6] sched/isolation: Introduce isolated task work To: Oleg Nesterov , Frederic Weisbecker CC: LKML , Andrew Morton , Ingo Molnar , Marcelo Tosatti , Michal Hocko , Peter Zijlstra , Thomas Gleixner , Valentin Schneider , Vlastimil Babka , References: <20250410152327.24504-1-frederic@kernel.org> <20250410152327.24504-6-frederic@kernel.org> <20250411102555.GA5322@redhat.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20250411102555.GA5322@redhat.com> Content-Type: text/plain; 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X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Apr 2025 05:12:17.5408 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: bb0e2777-abd3-4e18-c109-08dd79809867 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SA2PEPF000015C6.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW5PR12MB5598 On 4/11/2025 3:55 PM, Oleg Nesterov wrote: > >> + local_irq_save(flags); >> + if (task_work_queued(¤t->nohz_full_work)) { >> + ret = 0; >> + goto out; >> + } >> + >> + ret = task_work_add(current, ¤t->nohz_full_work, TWA_RESUME); >> +out: >> + local_irq_restore(flags); >> + return ret; > > Hmm, why not > > local_irq_save(flags); > if (task_work_queued(...)) > ret = 0; > else > ret = task_work_add(...); > > ? Or use guard() sand save on flags and ret: guard(irqsave)(); if (task_work_queued(...)) return 0; return task_work_add(...); -- Thanks and Regards, Prateek > > Oleg. > >