From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "snitzer@redhat.com" CC: "dm-devel@redhat.com" , "linux-kernel@vger.kernel.org" , "hch@infradead.org" , "linux-block@vger.kernel.org" , "osandov@fb.com" , "axboe@kernel.dk" , "ming.lei@redhat.com" Subject: Re: [dm-devel] [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle Date: Thu, 18 Jan 2018 21:39:15 +0000 Message-ID: <1516311554.2676.50.camel@wdc.com> References: <20180118024124.8079-1-ming.lei@redhat.com> <20180118170353.GB19734@redhat.com> <1516296056.2676.23.camel@wdc.com> <20180118183039.GA20121@redhat.com> <1516301278.2676.35.camel@wdc.com> <20180118204856.GA31679@redhat.com> <1516309128.2676.38.camel@wdc.com> <20180118212327.GB31679@redhat.com> In-Reply-To: <20180118212327.GB31679@redhat.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gVGh1LCAyMDE4LTAxLTE4IGF0IDE2OjIzIC0wNTAwLCBNaWtlIFNuaXR6ZXIgd3JvdGU6DQo+ IE9uIFRodSwgSmFuIDE4IDIwMTggYXQgIDM6NThQIC0wNTAwLA0KPiBCYXJ0IFZhbiBBc3NjaGUg PEJhcnQuVmFuQXNzY2hlQHdkYy5jb20+IHdyb3RlOg0KPiANCj4gPiBPbiBUaHUsIDIwMTgtMDEt MTggYXQgMTU6NDggLTA1MDAsIE1pa2UgU25pdHplciB3cm90ZToNCj4gPiA+IEZvciBCYXJ0J3Mg dGVzdCB0aGUgdW5kZXJseWluZyBzY3NpLW1xIGRyaXZlciBpcyB3aGF0IGlzIHJlZ3VsYXJseQ0K PiA+ID4gaGl0dGluZyB0aGlzIGNhc2UgaW4gX19ibGtfbXFfdHJ5X2lzc3VlX2RpcmVjdGx5KCk6 DQo+ID4gPiANCj4gPiA+ICAgICAgICAgaWYgKGJsa19tcV9oY3R4X3N0b3BwZWQoaGN0eCkgfHwg YmxrX3F1ZXVlX3F1aWVzY2VkKHEpKQ0KPiA+DQo+ID4gVGhlc2UgbG9ja3VwcyB3ZXJlIGFsbCB0 cmlnZ2VyZWQgYnkgaW5jb3JyZWN0IGhhbmRsaW5nIG9mDQo+ID4gLnF1ZXVlX3JxKCkgcmV0dXJu aW5nIEJMS19TVFNfUkVTT1VSQ0UuDQo+IA0KPiBQbGVhc2UgYmUgcHJlY2lzZSwgZG1fbXFfcXVl dWVfcnEoKSdzIHJldHVybiBvZiBCTEtfU1RTX1JFU09VUkNFPw0KPiAiSW5jb3JyZWN0IiBiZWNh dXNlIGl0IG5vIGxvbmdlciBydW5zIGJsa19tcV9kZWxheV9ydW5faHdfcXVldWUoKT8NCg0KSW4g d2hhdCBJIHdyb3RlIEkgd2FzIHJlZmVycmluZyB0byBib3RoIGRtX21xX3F1ZXVlX3JxKCkgYW5k IHNjc2lfcXVldWVfcnEoKS4NCldpdGggImluY29ycmVjdCIgSSBtZWFudCB0aGF0IHF1ZXVlIGxv Y2t1cHMgYXJlIGludHJvZHVjZWQgdGhhdCBtYWtlIHVzZXINCnNwYWNlIHByb2Nlc3NlcyB1bmtp bGxhYmxlLiBUaGF0J3MgYSBzZXZlcmUgYnVnLg0KDQo+IFBsZWFzZSB0cnkgdG8gZG8gbW9yZSB3 b3JrIGFuYWx5emluZyB0aGUgdGVzdCBjYXNlIHRoYXQgb25seSB5b3UgY2FuDQo+IGVhc2lseSBy dW4gKGR1ZSB0byBzcnBfdGVzdCBiZWluZyBhIFBJVEEpLg0KDQpJdCBpcyBub3QgY29ycmVjdCB0 aGF0IEknbSB0aGUgb25seSBvbmUgd2hvIGlzIGFibGUgdG8gcnVuIHRoYXQgc29mdHdhcmUuDQpB bnlvbmUgd2hvIGlzIHdpbGxpbmcgdG8gbWVyZ2UgdGhlIGxhdGVzdCBTUlAgaW5pdGlhdG9yIGFu ZCB0YXJnZXQgZHJpdmVyDQpwYXRjaGVzIGluIGhpcyBvciBoZXIgdHJlZSBjYW4gcnVuIHRoYXQg c29mdHdhcmUgaW4NCmFueSBWTS4gSSdtIHdvcmtpbmcgaGFyZA0Kb24gZ2V0dGluZyB0aGUgcGF0 Y2hlcyB1cHN0cmVhbSB0aGF0IG1ha2UgaXQgcG9zc2libGUgdG8gcnVuIHRoZSBzcnAtdGVzdA0K c29mdHdhcmUgb24gYSBzZXR1cCB0aGF0IGlzIG5vdCBlcXVpcHBlZCB3aXRoIEluZmluaUJhbmQg aGFyZHdhcmUuDQoNCj4gV2UgaGF2ZSB0aW1lIHRvIGdldCB0aGlzIHJpZ2h0LCBwbGVhc2Ugc3Rv cCBoeXBlcnZlbnRpbGF0aW5nIGFib3V0DQo+ICJyZWdyZXNzaW9ucyIuDQoNClNvcnJ5IE1pa2Ug YnV0IHRoYXQncyBzb21ldGhpbmcgSSBjb25zaWRlciBhcyBhbiB1bmZhaXIgY29tbWVudC4gSWYg TWluZyBhbmQNCnlvdSB3b3JrIG9uIHBhdGNoZXMgdG9nZXRoZXIsIGl0J3MgeW91ciBqb2IgdG8g bWFrZSBzdXJlIHRoYXQgbm8gcmVncmVzc2lvbnMNCmFyZSBpbnRyb2R1Y2VkLiBJbnN0ZWFkIG9m IGJsYW1pbmcgbWUgYmVjYXVzZSBJIHJlcG9ydCB0aGVzZSByZWdyZXNzaW9ucyB5b3UNCnNob3Vs ZCBiZSBncmF0ZWZ1bCB0aGF0IEkgdGFrZSB0aGUgdGltZSBhbmQgZWZmb3J0IHRvIHJlcG9ydCB0 aGVzZSByZWdyZXNzaW9ucw0KZWFybHkuIEFuZCBzaW5jZSB5b3UgYXJlIGVtcGxveWVkIGJ5IGEg bGFyZ2Ugb3JnYW5pemF0aW9uIHRoYXQgc2VsbHMgTGludXgNCnN1cHBvcnQgc2VydmljZXMsIHlv dXIgZW1wbG95ZXIgc2hvdWxkIGludmVzdCBpbiBkZXZlbG9waW5nIHRlc3QgY2FzZXMgdGhhdA0K cmVhY2ggYSBoaWdoZXIgY292ZXJhZ2Ugb2YgdGhlIGRtLCBTQ1NJIGFuZCBibG9jayBsYXllciBj b2RlLiBJIGRvbid0IHRoaW5rDQp0aGF0IGl0J3Mgbm9ybWFsIHRoYXQgbXkgdGVzdHMgZGlzY292 ZXJlZCBzZXZlcmFsIGlzc3VlcyB0aGF0IHdlcmUgbm90DQpkaXNjb3ZlcmVkIGJ5IFJlZCBIYXQn cyBpbnRlcm5hbCB0ZXN0IHN1aXRlLiBUaGF0J3Mgc29tZXRoaW5nIFJlZCBIYXQgaGFzIHRvDQph ZGRyZXNzLg0KDQpCYXJ0Lg==