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Fri, 20 Nov 2020 08:30:23 +0000 Received: from BYAPR11MB2632.namprd11.prod.outlook.com ([fe80::dc7e:c582:20a1:5bc7]) by BYAPR11MB2632.namprd11.prod.outlook.com ([fe80::dc7e:c582:20a1:5bc7%6]) with mapi id 15.20.3564.031; Fri, 20 Nov 2020 08:30:23 +0000 From: "Zhang,Qiang" Subject: SRCU: Question on srcu_advance_state To: paulmck@kernel.org Cc: "rcu@vger.kernel.org" , Joel Fernandes Message-ID: <7fc7b6b9-bcf2-fa78-1931-415d04a5ac1a@windriver.com> Date: Fri, 20 Nov 2020 16:30:15 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [60.247.85.82] X-ClientProxiedBy: HK2PR02CA0128.apcprd02.prod.outlook.com (2603:1096:202:16::12) To BYAPR11MB2632.namprd11.prod.outlook.com (2603:10b6:a02:c4::17) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [128.224.162.183] (60.247.85.82) by HK2PR02CA0128.apcprd02.prod.outlook.com (2603:1096:202:16::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3589.20 via Frontend Transport; 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X-MS-Exchange-AntiSpam-MessageData: LxOShGRGxQktWPmr+aTqCN+pTzzGNHVpEzCDPsqBoIxAJxjVjdN5NS44w277Ri4D+sXNNQ4A19+693YDXvF/qP4Mw3BbCQm8vE1PjchNUrSn5lwSI9lt1FMibLCpHGiyn9ACB7HorVKIzhdn6n5FAw4djSM9MVZLWX6Vjvsb2AaXtMqQJdAfG82XhhygaTL8tayf9GXW6EiY8Ic2eaLlYLmmL14BHyt7wPiuJ5YH0z3fhIzlouiPM+Ws9kQdFaCua4ZM17HKajx9bBcQp0QNiJ7eRiWVByqJ1dT1E0Z31Oc+K0xE31NO2fWlidNl2ZcOpi5XPaXzTkn415mgUnyBZIrPXriDn2RZFvkdN25np+JSzuy2Q/Vq8JUai8ya5zXCgmXJLCJ+dCpWPZ8Xm1lj1mU9Ugh4OOTpvSzM8crF1QGBxNMF+ezpO5Z/CwzFIW4GZISWSPNw1T5gQH4d98l7WOgmK5QZ0foGSW/ADfdsI16rAAWTWwjG+luRaYgGWmjQcvSd/nrhJi7kdKFSJB7NJp9dOmFuR+stNmgetejjU9jlM2h+xdMyoqoejwSgvyahO1DgwJFMupdcQ0lVzixO2bWa640Rnw8Sw2vunpoNYS7y8rW87OAXgR+dy12hodf+7EA/Pjt9j0SahkJaVcNVWg== X-OriginatorOrg: windriver.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0d6541b1-362c-499d-01f7-08d88d2e85d2 X-MS-Exchange-CrossTenant-AuthSource: BYAPR11MB2632.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Nov 2020 08:30:22.8978 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Gur5NyDFi0gH/ce1Ew1GwESD0KQNEEGt8jKK7iKiK6Dab777OAn+ebPoI5a5LQfhc6xzHbqWyhe5AtG/VsC+ggU8j2JZWtdog318qxXjVC0= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR11MB4976 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Hello Pual sorry to disturb you, I also have some quesetion for you: in srcu_advance_state function, when seq state == SRCU_STATE_SCAN1, we will check, if the previous readers critical region exits, will be returned directly. I'd like to know under what scenario this will happen? Thanks Qiang