From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "zhangweiping@didichuxing.com" CC: "linux-block@vger.kernel.org" , "axboe@kernel.dk" Subject: Re: [PATCH] blk-mq: fix nr_requests wrong value when modify it from sysfs Date: Wed, 6 Sep 2017 13:00:44 +0000 Message-ID: <1504702843.7750.0.camel@wdc.com> References: <20170903134634.GA27411@localhost.didichuxing.com> <1504626163.4135.33.camel@wdc.com> <20170906073355.GA37455@localhost.didichuxing.com> In-Reply-To: <20170906073355.GA37455@localhost.didichuxing.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gV2VkLCAyMDE3LTA5LTA2IGF0IDE1OjM0ICswODAwLCB3ZWlwaW5nIHpoYW5nIHdyb3RlOg0K PiBPbiBUdWUsIFNlcCAwNSwgMjAxNyBhdCAwMzo0Mjo0NVBNICswMDAwLCBCYXJ0IFZhbiBBc3Nj aGUgd3JvdGU6DQo+ID4gT24gU3VuLCAyMDE3LTA5LTAzIGF0IDIxOjQ2ICswODAwLCB3ZWlwaW5n IHpoYW5nIHdyb3RlOg0KPiA+ID4gaWYgYmxrLW1xIHVzZSAibm9uZSIgaW8gc2NoZWR1bGVyLCBu cl9yZXF1ZXN0IGdldCBhIHdyb25nIHZhbHVlIHdoZW4NCj4gPiA+IGlucHV0IGEgbnVtYmVyID4g dGFnX3NldC0+cXVldWVfZGVwdGguIGJsa19tcV90YWdfdXBkYXRlX2RlcHRoIHdpbGwgZ2V0DQo+ ID4gPiB0aGUgc21hbGxlciBvbmUgbWluKG5yLCBzZXQtPnF1ZXVlX2RlcHRoKSwgYW5kIHRoZW4g cS0+bnJfcmVxdWVzdCBnZXQgYQ0KPiA+ID4gd3JvbmcgdmFsdWUuDQo+ID4gPiANCj4gPiA+IFJl cHJvZHVjZToNCj4gPiA+IA0KPiA+ID4gZWNobyBub25lID4gL3N5cy9ibG9jay9udm1lMG4xL3F1 ZXVlL2lvc2NoZWR1bGVyDQo+ID4gPiBlY2hvIDEwMDAwMDAgPiAvc3lzL2Jsb2NrL252bWUwbjEv cXVldWUvbnJfcmVxdWVzdHMNCj4gPiA+IGNhdCAvc3lzL2Jsb2NrL252bWUwbjEvcXVldWUvbnJf cmVxdWVzdHMNCj4gPiA+IDEwMDAwMDANCj4gPiA+IA0KPiA+ID4gU2lnbmVkLW9mZi1ieTogd2Vp cGluZyB6aGFuZyA8emhhbmd3ZWlwaW5nQGRpZGljaHV4aW5nLmNvbT4NCj4gPiA+IC0tLQ0KPiA+ ID4gIGJsb2NrL2Jsay1tcS5jIHwgNyArKysrKy0tDQo+ID4gPiAgMSBmaWxlIGNoYW5nZWQsIDUg aW5zZXJ0aW9ucygrKSwgMiBkZWxldGlvbnMoLSkNCj4gPiA+IA0KPiA+ID4gZGlmZiAtLWdpdCBh L2Jsb2NrL2Jsay1tcS5jIGIvYmxvY2svYmxrLW1xLmMNCj4gPiA+IGluZGV4IGY4NGQxNDUuLjgz MDNlNWUgMTAwNjQ0DQo+ID4gPiAtLS0gYS9ibG9jay9ibGstbXEuYw0KPiA+ID4gKysrIGIvYmxv Y2svYmxrLW1xLmMNCj4gPiA+IEBAIC0yNjIyLDggKzI2MjIsMTEgQEAgaW50IGJsa19tcV91cGRh dGVfbnJfcmVxdWVzdHMoc3RydWN0IHJlcXVlc3RfcXVldWUgKnEsIHVuc2lnbmVkIGludCBucikN Cj4gPiA+ICAJCSAqIHF1ZXVlIGRlcHRoLiBUaGlzIGlzIHNpbWlsYXIgdG8gd2hhdCB0aGUgb2xk IGNvZGUgd291bGQgZG8uDQo+ID4gPiAgCQkgKi8NCj4gPiA+ICAJCWlmICghaGN0eC0+c2NoZWRf dGFncykgew0KPiA+ID4gLQkJCXJldCA9IGJsa19tcV90YWdfdXBkYXRlX2RlcHRoKGhjdHgsICZo Y3R4LT50YWdzLA0KPiA+ID4gLQkJCQkJCQltaW4obnIsIHNldC0+cXVldWVfZGVwdGgpLA0KPiA+ ID4gKwkJCWlmIChuciA+IHNldC0+cXVldWVfZGVwdGgpIHsNCj4gPiA+ICsJCQkJbnIgPSBzZXQt PnF1ZXVlX2RlcHRoOw0KPiA+ID4gKwkJCQlwcl93YXJuKCJyZWR1Y2UgbnJfcmVxdWVzdCB0byAl dVxuIiwgbnIpOw0KPiA+ID4gKwkJCX0NCj4gPiA+ICsJCQlyZXQgPSBibGtfbXFfdGFnX3VwZGF0 ZV9kZXB0aChoY3R4LCAmaGN0eC0+dGFncywgbnIsDQo+ID4gPiAgCQkJCQkJCWZhbHNlKTsNCj4g PiA+ICAJCX0gZWxzZSB7DQo+ID4gPiAgCQkJcmV0ID0gYmxrX21xX3RhZ191cGRhdGVfZGVwdGgo aGN0eCwgJmhjdHgtPnNjaGVkX3RhZ3MsDQo+ID4gDQo+ID4gU2hvdWxkbid0IHRoaXMgY29kZSBy ZXR1cm4gLUVJTlZBTCBvciAtRVJBTkdFIGlmICducicgaXMgdG9vIGxhcmdlPyBUaGF0IHdpbGwg aGVscCB0bw0KPiA+IGtlZXAgdXNlciBzcGFjZSBjb2RlIHNpbXBsZSB0aGF0IHVwZGF0ZXMgdGhl IHF1ZXVlIGRlcHRoLg0KPiANCj4gSGkgQmFydCwNCj4gDQo+IFRoZSByZWFzb24gd2h5IG5vdCBy ZXR1cm4gLUVJTlZBTCBpcyBrZWVwaW5nIGFsaW4gd2l0aCBtaW5pbXVtIGNoZWNraW5nIGluIHF1 ZXVlX3JlcXVlc3RzX3N0b3JlLA0KPiBpZiB5b3UgaW5zaXN0IHJldHVybiAtRUlOVkFMLy1FUkFO R0UsIG1pbmltdW0gY2hlY2tpbmcgc2hvdWxkIGFsc28ga2VlcA0KPiBzYW1lIGJlaGF2aW9yLiBC b3RoIHJldHVybiBlcnJvciBtZWVzYWdlIGFuZCBxdWlldGx5IGNoYW5naW5nIGFyZSBva2V5DQo+ IGZvciBtZS4gV2hpY2ggd2F5IGRvIHlvdSBwcmVmZXIgPw0KPiANCj4gc3RhdGljIHNzaXplX3QN Cj4gcXVldWVfcmVxdWVzdHNfc3RvcmUoc3RydWN0IHJlcXVlc3RfcXVldWUgKnEsIGNvbnN0IGNo YXIgKnBhZ2UsIHNpemVfdCBjb3VudCkNCj4gew0KPiAJdW5zaWduZWQgbG9uZyBucjsNCj4gCWlu dCByZXQsIGVycjsNCj4gDQo+IAlpZiAoIXEtPnJlcXVlc3RfZm4gJiYgIXEtPm1xX29wcykNCj4g CQlyZXR1cm4gLUVJTlZBTDsNCj4gDQo+IAlyZXQgPSBxdWV1ZV92YXJfc3RvcmUoJm5yLCBwYWdl LCBjb3VudCk7DQo+IAlpZiAocmV0IDwgMCkNCj4gCQlyZXR1cm4gcmV0Ow0KPiANCj4gCWlmIChu ciA8IEJMS0RFVl9NSU5fUlEpDQo+IAkJbnIgPSBCTEtERVZfTUlOX1JROw0KDQpIZWxsbyBKZW5z LA0KDQpEbyB5b3UgcGVyaGFwcyBoYXZlIGEgcHJlZmVyZW5jZSBmb3Igb25lIG9mIHRoZSBhcHBy b2FjaGVzIHRoYXQgaGF2ZSBiZWVuIGRpc2N1c3NlZA0KaW4gdGhpcyBlLW1haWwgdGhyZWFkPw0K DQpUaGFua3MsDQoNCkJhcnQu