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Wed, 8 Jul 2026 21:11:16 +0000 Message-ID: <3af17868-6ab2-4a22-907f-e994a1b18ccd@intel.com> Date: Wed, 8 Jul 2026 14:11:13 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 05/11] x86/virt/tdx: Handle concurrent callers in tdx_pamt_get/put() Content-Language: en-US To: "Edgecombe, Rick P" , "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" , "Huang, Kai" , "Hansen, Dave" , "Zhao, Yan Y" , "kas@kernel.org" , "seanjc@google.com" , "mingo@redhat.com" , "linux-kernel@vger.kernel.org" , "pbonzini@redhat.com" , "nik.borisov@suse.com" , "linux-doc@vger.kernel.org" , "hpa@zytor.com" , "tglx@kernel.org" , "Annapurve, Vishal" , "bp@alien8.de" , "Gao, Chao" , "x86@kernel.org" CC: "kirill.shutemov@linux.intel.com" References: <20260526023515.288829-1-rick.p.edgecombe@intel.com> <20260526023515.288829-6-rick.p.edgecombe@intel.com> <1d60cebf-4764-4785-bf01-8ca59ab2cc7d@intel.com> From: Sohil Mehta In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR05CA0131.namprd05.prod.outlook.com (2603:10b6:a03:33d::16) To DS0PR11MB7997.namprd11.prod.outlook.com (2603:10b6:8:125::14) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR11MB7997:EE_|SA1PR11MB5873:EE_ X-MS-Office365-Filtering-Correlation-Id: 4b202f5c-09d0-4a8b-5dda-08dedd357297 X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|366016|1800799024|23010399003|921020|22082099003|18002099003|56012099006|11063799006|4143699003; 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They do not strictly need >> to be because all access is protected by pamt_lock. The overhead >> of an atomic_t in this situation is minuscule compared to the >> global lock. Leave the (unnecessary) atomic_t in place to enable >> future optimization with minimal churn. >> The atomic_t is introduced primarily by this patch (and slightly by the previous one). Instead of "Leave the atomic_t in place", would it be more appropriate to say "Use an (unnecessary) atomic_t to enable future ..."? >> Does that work for everybody? > Yes, this works. > Works for me, thanks.