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Peter Anvin" , Andy Lutomirski , Jens Axboe , Christian Brauner , Peter Zijlstra , Shuah Khan , Arnd Bergmann , Jonathan Corbet , Ashok Raj , Jacob Pan , "Gayatri Kammela" , Zeng Guang , "Dan Williams" , Randy E Witt , Ravi V Shankar , Ramesh Thomas , , , , References: <20210913200132.3396598-1-sohil.mehta@intel.com> <20210913200132.3396598-7-sohil.mehta@intel.com> From: Sohil Mehta Message-ID: Date: Mon, 27 Sep 2021 16:20:25 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.14.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-ClientProxiedBy: BYAPR03CA0029.namprd03.prod.outlook.com (2603:10b6:a02:a8::42) To BYAPR11MB3320.namprd11.prod.outlook.com (2603:10b6:a03:18::25) MIME-Version: 1.0 Received: from [192.168.86.37] (73.222.31.188) by BYAPR03CA0029.namprd03.prod.outlook.com (2603:10b6:a02:a8::42) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4544.13 via Frontend Transport; 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/* bit 0: ON, bit 1: SN, bit 2-7: reserved */ >> + u8 reserved1; /* Reserved */ >> + u8 nv; /* Notification vector */ >> + u8 reserved2; /* Reserved */ > What are these "reserved" for? The UPID is an architectural data structure defined by the hardware. The reserved fields are defined by the hardware (likely to keep the structure size as 16 bytes). > >> +struct uintr_upid_ctx { >> + struct uintr_upid *upid; >> + refcount_t refs; > Please use a kref for this and do not roll your own for no good reason. Sure. Will do.