From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.hgst.iphmx.com ([68.232.143.124]:48064 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752655AbdKFQeY (ORCPT ); Mon, 6 Nov 2017 11:34:24 -0500 From: Bart Van Assche To: "ming.lei@redhat.com" CC: "hch@infradead.org" , "linux-block@vger.kernel.org" , "osandov@fb.com" , "axboe@fb.com" , "hare@suse.com" Subject: Re: [PATCH] blk-mq: respect queue dead via blk_mq_quiesce_queue Date: Mon, 6 Nov 2017 16:34:21 +0000 Message-ID: <1509986060.2409.17.camel@wdc.com> References: <20171105121008.28180-1-ming.lei@redhat.com> <1509896328.2697.4.camel@wdc.com> <20171106034423.GC26416@ming.t460p> In-Reply-To: <20171106034423.GC26416@ming.t460p> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org T24gTW9uLCAyMDE3LTExLTA2IGF0IDExOjQ0ICswODAwLCBNaW5nIExlaSB3cm90ZToNCj4gT24g U3VuLCBOb3YgMDUsIDIwMTcgYXQgMDM6Mzg6NDlQTSArMDAwMCwgQmFydCBWYW4gQXNzY2hlIHdy b3RlOg0KPiA+IE9uIFN1biwgMjAxNy0xMS0wNSBhdCAyMDoxMCArMDgwMCwgTWluZyBMZWkgd3Jv dGU6DQo+ID4gPiBkaWZmIC0tZ2l0IGEvYmxvY2svYmxrLWNvcmUuYyBiL2Jsb2NrL2Jsay1jb3Jl LmMNCj4gPiA+IGluZGV4IDA0OGJlNGFhNjAyNC4uMGIxMjFmMjllM2IxIDEwMDY0NA0KPiA+ID4g LS0tIGEvYmxvY2svYmxrLWNvcmUuYw0KPiA+ID4gKysrIGIvYmxvY2svYmxrLWNvcmUuYw0KPiA+ ID4gQEAgLTY1OCw2ICs2NTgsMTAgQEAgdm9pZCBibGtfY2xlYW51cF9xdWV1ZShzdHJ1Y3QgcmVx dWVzdF9xdWV1ZSAqcSkNCj4gPiA+ICAJcXVldWVfZmxhZ19zZXQoUVVFVUVfRkxBR19ERUFELCBx KTsNCj4gPiA+ICAJc3Bpbl91bmxvY2tfaXJxKGxvY2spOw0KPiA+ID4gIA0KPiA+ID4gKwkvKiBy ZXNwZWN0IHF1ZXVlIERFQUQgdmlhIHF1aWVzY2UgZm9yIGJsay1tcSAqLw0KPiA+ID4gKwlpZiAo cS0+bXFfb3BzKQ0KPiA+ID4gKwkJYmxrX21xX3F1aWVzY2VfcXVldWUocSk7DQo+ID4gPiArDQo+ ID4gPiAgCS8qIGZvciBzeW5jaHJvbm91cyBiaW8tYmFzZWQgZHJpdmVyIGZpbmlzaCBpbi1mbGln aHQgaW50ZWdyaXR5IGkvbyAqLw0KPiA+ID4gIAlibGtfZmx1c2hfaW50ZWdyaXR5KCk7DQo+ID4g DQo+ID4gSGF2ZSB5b3UgY29uc2lkZXJlZCB0byBjaGFuZ2UgdGhlIGJsa19mcmVlemVfcXVldWVf c3RhcnQoKSBjYWxsIGluDQo+ID4gYmxrX3NldF9xdWV1ZV9keWluZygpIGludG8gYSBibGtfZnJl ZXplX3F1ZXVlKCkgY2FsbD8gVGhhdCBhcHByb2FjaCBoYXMgdGhlDQo+ID4gYWR2YW50YWdlIHRo YXQgbm8gbmV3IGlmIChxLT5tcV9vcHMpIHRlc3QgaGFzIHRvIGJlIGludHJvZHVjZWQuDQo+IA0K PiBUaGF0IGFwcHJvYWNoIGlzbid0IG5vdGhpbmcgdG8gZG8gd2l0aCB0aGlzIGlzc3VlLCBhbmQg Y2FuJ3QgZml4IHRoaXMgaXNzdWUNCj4gdG9vLg0KDQpTb3JyeSBidXQgSSBkaXNhZ3JlZS4gTXkg b3BpbmlvbiBpcyB0aGF0IHRoZSBjaGFuZ2UgSSBwcm9wb3NlZCBpcyBhIG1vcmUNCmVsZWdhbnQg d2F5IHRvIGF2b2lkIHRoYXQgYmxrX21xX3J1bl9od19xdWV1ZSgpIHRyaWVzIHRvIGV4ZWN1dGUg YSByZXF1ZXN0DQphZnRlciBibGtfY2xlYW51cF9xdWV1ZSgpIGhhcyBzdGFydGVkLg0KDQo+IE5v dCBtZW50aW9uIHdlIGhvbGQgcS0+c3lzZnNfbG9jayBiZWZvcmUgY2FsbGluZyBibGtfc2V0X3F1 ZXVlX2R5aW5nKCksDQo+IHRoZXJlIG1heSBiZSByaXNrIHRvIGNhdXNlIGRlYWRsb2NrLg0KDQpT b3JyeSBidXQgSSBkaXNhZ3JlZSBhZ2Fpbi4gcS0+c3lzZnNfbG9jayBpcyBub3Qgb2J0YWluZWQg ZnJvbSBpbnNpZGUgYW55DQpjb2RlIHRoYXQgcnVucyB0aGUgcXVldWUgc28gdGhlcmUgaXMgbm8g ZGVhZGxvY2sgcmlzay4gQWRkaXRpb25hbGx5LCBJIGRvdWJ0DQp0aGF0IGl0IGlzIHVzZWZ1bCB0 byBvYnRhaW4gcS0+c3lzZnNfbG9jayBmcm9tIGluc2lkZSBibGtfY2xlYW51cF9xdWV1ZSgpLg0K VGhlIHF1ZXVlIGF0dHJpYnV0ZXMgdGhhdCBhcmUgZXhwb3J0ZWQgdGhyb3VnaCBzeXNmcyBjYW4g YmUgbW9kaWZpZWQgc2FmZWx5DQp1bnRpbCB0aGVzZSBzeXNmcyBhdHRyaWJ1dGVzIGFyZSByZW1v dmVkLg0KDQo+IFRoZSBpc3N1ZSBpcyB0aGF0IHRoZXJlIGlzbid0IGFueSByZXF1ZXN0IGluIHF1 ZXVlKHF1ZXVlIGlzIGZyb3plbiksIGJ1dA0KPiBkaXNwYXRjaCBzdGlsbCBtYXkgaGFwcGVuLCBs ZXQgbWUgZXhwbGFpbiBpdCBhIGJpdDoNCj4gDQo+IDEpIHRoZXJlIGFyZSBzZXZlcmFsIElPIHN1 Ym1pdCBwYXRocyBpbi1wcm9ncmVzcw0KPiAyKSByZXF1ZXN0cyBmcm9tIGFsbCB0aGVzZSBwYXRo cyBhcmUgaW5zZXJ0ZWQgdG8gcXVldWUsIGJ1dCBtYXkgZGlzcGF0Y2ggdG8NCj4gTExEIGluIG9u bHkgb25lIG9mIHRoZXNlIHBhdGhzLCBidXQgb3RoZXIgcGF0aHMgbWF5IHN0aWxsIG1vdmUgb24g dG8gZGlzcGF0Y2gNCj4gZXZlbiBhbGwgdGhlc2UgcmVxdWVzdHMgYXJlIGNvbXBsZXRlZCh0aGF0 IG1lYW5zIGJsa19tcV9mcmVlemVfcXVldWVfd2FpdCgpDQo+IHJldHVybnMgYXQgdGhhdCB0aW1l KQ0KPiAzKSB0aGUgZGlzcGF0Y2ggYWZ0ZXIgcXVldWUgZGVhZCBoYXBwZW5zIGFuZCBjYXVzZXMg dGhlIHVzZS1hZnRlci1mcmVlLA0KPiBiZWNhdXNlIHdlIG5ldmVyIHJlc3BlY3QgcXVldWUgZGVh ZCBmb3IgYmxrLW1xLg0KDQpBZnRlciBhIHF1ZXVlIGhhcyBiZWVuIG1hcmtlZCAiZHlpbmciIGFu ZCBhZnRlciBibGtfZnJlZXplX3F1ZXVlKCkgaGFzDQpyZXR1cm5lZCBpdCBpcyBndWFyYW50ZWVk IHRoYXQgYWxsIHJlcXVlc3RzIGhhdmUgZmluaXNoZWQgYW5kIHRoYXQgYWxsIGZ1dHVyZQ0KYmxr X2dldF9yZXF1ZXN0KCkgY2FsbHMgd2lsbCBmYWlsLiBIZW5jZSAucXVldWVfcnEoKSB3b24ndCBi ZSBjYWxsZWQgYW55bW9yZS4NCkFueSBjb2RlIHRoYXQgcnVucyBhIHF1ZXVlICh0aGUgX19ibGtf bXFfcnVuX2h3X3F1ZXVlKCkgLyBibGtfbXFfbWFrZV9yZXF1ZXN0KCkNCmNhbGxlcnMpIG11c3Qg aG9sZCBhIHJlZmVyZW5jZSBvbiB0aGF0IHF1ZXVlLiBSdW5uaW5nIGEgcXVldWUgZXZlbiBhZnRl cg0KYmxrX2NsZWFudXBfcXVldWUoKSBmaW5pc2hlZCBpcyBzYWZlIGFzIGxvbmcgYXMgdGhlIGNh bGxlciBob2xkcyBhIHJlZmVyZW5jZQ0Kb24gdGhhdCBxdWV1ZS4gU28gdGhlIHNjZW5hcmlvIGRl c2NyaWJlZCBhYm92ZSB3b24ndCBsZWFkIHRvIGEgY3Jhc2guDQoNCkJhcnQu