From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "tj@kernel.org" CC: "hch@lst.de" , "linux-block@vger.kernel.org" , "axboe@kernel.dk" Subject: Re: [PATCH] blk-mq: Fix a race between resetting the timer and completion handling Date: Mon, 5 Feb 2018 21:33:03 +0000 Message-ID: <1517866382.3764.43.camel@wdc.com> References: <20180201224930.17918-1-bart.vanassche@wdc.com> <20180205210601.GP1121507@devbig577.frc2.facebook.com> In-Reply-To: <20180205210601.GP1121507@devbig577.frc2.facebook.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gTW9uLCAyMDE4LTAyLTA1IGF0IDEzOjA2IC0wODAwLCBUZWp1biBIZW8gd3JvdGU6DQo+IFRo YW5rcyBhIGxvdCBmb3IgdGVzdGluZyBhbmQgZml4aW5nIHRoZSBpc3N1ZXMgYnV0IEknbSBhIGJp dCBjb25mdXNlZA0KPiBieSB0aGUgcGF0Y2guICBNYXliZSB3ZSBjYW4gc3BsaXQgcGF0Y2ggYSBi aXQgbW9yZT8gIFRoZXJlIHNlZW0gdG8gYmUNCj4gdGhyZWUgdGhpbmdzIGdvaW5nIG9uLA0KPiAN Cj4gMS4gQ2hhbmdpbmcgcHJlZW1wdGlvbiBwcm90ZWN0aW9uIHRvIGlycSBwcm90ZWN0aW9uIGlu IGlzc3VlIHBhdGguDQo+IA0KPiAyLiBNZXJnZSBvZiBhYm9ydGVkX2dzdGF0ZV9zeW5jIGFuZCBn c3RhdGVfc2VxLg0KPiANCj4gMy4gVXBkYXRlcyB0byBibGtfbXFfcnFfdGltZWRfb3V0KCkuDQo+ IA0KPiBBcmUgYWxsIHRocmVlIGNoYW5nZXMgbmVjZXNzYXJ5IGZvciBzdGFiaWxpdHk/DQoNCkhl bGxvIFRlanVuLA0KDQpNeSBnb2FsIHdpdGggdGhpcyBwYXRjaCBpcyB0byBmaXggdGhlIHJhY2Ug YmV0d2VlbiByZXNldHRpbmcgdGhlIHRpbWVyIGFuZA0KdGhlIGNvbXBsZXRpb24gcGF0aC4gSGVu Y2UgY2hhbmdlICgzKS4gQ2hhbmdlcyAoMSkgYW5kICgyKSBhcmUgbmVlZGVkIHRvDQptYWtlIHRo ZSBjaGFuZ2VzIGluIGJsa19tcV9ycV90aW1lZF9vdXQoKSB3b3JrLg0KDQo+ID4gQEAgLTgzMSwx MyArODM0LDEyIEBAIHN0YXRpYyB2b2lkIGJsa19tcV9ycV90aW1lZF9vdXQoc3RydWN0IHJlcXVl c3QgKnJlcSwgYm9vbCByZXNlcnZlZCkNCj4gPiAgCQlfX2Jsa19tcV9jb21wbGV0ZV9yZXF1ZXN0 KHJlcSk7DQo+ID4gIAkJYnJlYWs7DQo+ID4gIAljYXNlIEJMS19FSF9SRVNFVF9USU1FUjoNCj4g PiAtCQkvKg0KPiA+IC0JCSAqIEFzIG5vdGhpbmcgcHJldmVudHMgZnJvbSBjb21wbGV0aW9uIGhh cHBlbmluZyB3aGlsZQ0KPiA+IC0JCSAqIC0+YWJvcnRlZF9nc3RhdGUgaXMgc2V0LCB0aGlzIG1h eSBsZWFkIHRvIGlnbm9yZWQNCj4gPiAtCQkgKiBjb21wbGV0aW9ucyBhbmQgZnVydGhlciBzcHVy aW91cyB0aW1lb3V0cy4NCj4gPiAtCQkgKi8NCj4gPiAtCQlibGtfbXFfcnFfdXBkYXRlX2Fib3J0 ZWRfZ3N0YXRlKHJlcSwgMCk7DQo+ID4gKwkJbG9jYWxfaXJxX2Rpc2FibGUoKTsNCj4gPiArCQl3 cml0ZV9zZXFjb3VudF9iZWdpbigmcmVxLT5nc3RhdGVfc2VxKTsNCj4gPiAgCQlibGtfYWRkX3Rp bWVyKHJlcSk7DQo+ID4gKwkJcmVxLT5hYm9ydGVkX2dzdGF0ZSA9IDA7DQo+ID4gKwkJd3JpdGVf c2VxY291bnRfZW5kKCZyZXEtPmdzdGF0ZV9zZXEpOw0KPiA+ICsJCWxvY2FsX2lycV9lbmFibGUo KTsNCj4gPiAgCQlicmVhazsNCj4gDQo+IFNvLCB0aGlzIGlzICMzIGFuZCBJJ20gbm90IHN1cmUg aG93IGFkZGluZyBnc3RhdGVfc2VxIHByb3RlY3Rpb24gZ2V0cw0KPiByaWQgb2YgdGhlIHJhY2Ug Y29uZGl0aW9uIG1lbnRpb25lZCBpbiB0aGUgY29tbWVudC4gIEl0J3Mgc3RpbGwgdGhlDQo+IHNh bWUgdGhhdCBub3RoaW5nIGlzIHByb3RlY3RpbmcgYWdhaW5zdCByYWNpbmcgdy8gY29tcGxldGlv bi4NCg0KSSB0aGluayB5b3UgYXJlIHJpZ2h0LiBJIHdpbGwgc2VlIHdoZXRoZXIgSSBjYW4gcmV3 b3JrIHRoaXMgcGF0Y2ggdG8gYWRkcmVzcw0KdGhhdCByYWNlLg0KDQpUaGFua3MsDQoNCkJhcnQu DQoNCg0K