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Thread-Topic: [PATCH] smp: Do not warn if smp_call_function_single() is doing a self call. Thread-Index: AQHU84XIPd58XT1sd0attup0EFB40aY94IwA Date: Mon, 15 Apr 2019 23:39:57 +0000 Message-ID: References: <20190412235341.29379-1-decui@microsoft.com> <20190415122128.GO11158@hirez.programming.kicks-ass.net> In-Reply-To: <20190415122128.GO11158@hirez.programming.kicks-ass.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: msip_labels: MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Enabled=True; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SiteId=72f988bf-86f1-41af-91ab-2d7cd011db47; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Owner=decui@microsoft.com; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SetDate=2019-04-15T23:39:54.3315002Z; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Name=General; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Application=Microsoft Azure Information Protection; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ActionId=49f62ccb-ea35-42ea-b712-cc1ed31dc74d; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Extended_MSFT_Method=Automatic authentication-results: spf=none (sender IP is ) smtp.mailfrom=decui@microsoft.com; x-originating-ip: [2001:4898:80e8:2:5ccc:8ef3:4a1f:27b] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 3ff43cbb-1fda-429a-c2dc-08d6c1fbaba9 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600140)(711020)(4605104)(4618075)(2017052603328)(7193020);SRVR:PU1P153MB0170; x-ms-traffictypediagnostic: PU1P153MB0170: x-ld-processed: 72f988bf-86f1-41af-91ab-2d7cd011db47,ExtAddr x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:4714; x-forefront-prvs: 000800954F x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(376002)(136003)(346002)(39860400002)(366004)(199004)(189003)(54906003)(5660300002)(4326008)(229853002)(68736007)(22452003)(71190400001)(6116002)(6436002)(4744005)(7416002)(6916009)(53936002)(106356001)(2906002)(52536014)(9686003)(25786009)(33656002)(55016002)(105586002)(86612001)(316002)(74316002)(305945005)(7736002)(86362001)(14454004)(102836004)(8676002)(11346002)(186003)(6246003)(8990500004)(14444005)(99286004)(256004)(71200400001)(10090500001)(476003)(7696005)(76176011)(97736004)(81156014)(478600001)(53546011)(8936002)(446003)(10290500003)(6506007)(46003)(81166006)(486006);DIR:OUT;SFP:1102;SCL:1;SRVR:PU1P153MB0170;H:PU1P153MB0169.APCP153.PROD.OUTLOOK.COM;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: microsoft.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: 5MuGwtUKrf6lddAOH4vsNADHf4MIpEBYQmaO1pwGKTT8jKvm9ZlpJk3cqcBh6KRrj9j1aLZjRHY/DuWJwAXeZk69dbgtG2BL33fG7ZAyPCY6Fi5naKRMdaFcWQ6olWqkJXCMl2q+9dVGCGGgsovkwsJWnVzPqJh727SztkXOY4kjGsqddbOYs6ykIIjBHRdKrNQn9eawRM4RHiAdYop89fRyNUBMNeHRo88wgUdfv+rv9Im0MqpcTvb1pmSwLlyTHEMt9f8EsAnQIBsUvRqrICocxo7CaJckTHfHirHRsmtOuVrcRfQRaDKC2DLT8t7131Ja2IsFxMyCvEgmEurfqRIYgoIh10sPVXF7zcFh3vN2jD/pkxfiq6JT4j8SlbwHG/soqUdKzXZ9DBdKRNJxEe8XEThKRzFIa3M/iUvMnlU= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3ff43cbb-1fda-429a-c2dc-08d6c1fbaba9 X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Apr 2019 23:39:57.5458 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-Transport-CrossTenantHeadersStamped: PU1P153MB0170 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Peter Zijlstra > Sent: Monday, April 15, 2019 5:21 AM > To: Dexuan Cui >=20 > On Fri, Apr 12, 2019 at 11:53:57PM +0000, Dexuan Cui wrote: > > If smp_call_function_single() is calling the function for itself, it's = safe > > to run with irqs_disabled() =3D=3D true. > > > > I hit the warning because I'm in the below path in the .suspend callbac= k of > > a "syscore_ops" to support hibernation for a VM running on Hyper-V: > > > > hv_synic_cleanup() -> > > clockevents_unbind_device() -> > > clockevents_unbind() -> > > smp_call_function_single(). > > > > When the .suspend callback runs, only CPU0 is online and irqs_disabled(= ) is > > true. >=20 > Pray tell, how well do you think mutex_lock() works with interrupts > disabled? Good point. I realized generally speaking this patch makes no sense, so let= me try the solution proposed by Vitaly, i.e. fix clockevents_unbind() instead. Thanks, -- Dexuan