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" , "hch@infradead.org" , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "osandov@fb.com" , "ming.lei@redhat.com" , "axboe@kernel.dk" Subject: Re: [RFC PATCH] blk-mq: fixup RESTART when queue becomes idle Date: Thu, 18 Jan 2018 17:20:57 +0000 Message-ID: <1516296056.2676.23.camel@wdc.com> References: <20180118024124.8079-1-ming.lei@redhat.com> <20180118170353.GB19734@redhat.com> In-Reply-To: <20180118170353.GB19734@redhat.com> Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gVGh1LCAyMDE4LTAxLTE4IGF0IDEyOjAzIC0wNTAwLCBNaWtlIFNuaXR6ZXIgd3JvdGU6DQo+ IE9uIFRodSwgSmFuIDE4IDIwMTggYXQgMTE6NTBhbSAtMDUwMCwNCj4gQmFydCBWYW4gQXNzY2hl IDxiYXJ0LnZhbmFzc2NoZUB3ZGMuY29tPiB3cm90ZToNCj4gPiBNeSBjb21tZW50cyBhYm91dCB0 aGUgYWJvdmUgYXJlIGFzIGZvbGxvd3M6DQo+ID4gLSBJdCBjYW4gdGFrZSB1cCB0byBxLT5ycV90 aW1lb3V0IGppZmZpZXMgYWZ0ZXIgYSAucXVldWVfcnEoKQ0KPiA+ICAgaW1wbGVtZW50YXRpb24g cmV0dXJuZWQgQkxLX1NUU19SRVNPVVJDRSBiZWZvcmUgYmxrX21xX3RpbWVvdXRfd29yaygpDQo+ ID4gICBnZXRzIGNhbGxlZC4gSG93ZXZlciwgaXQgY2FuIGhhcHBlbiB0aGF0IG9ubHkgYSBmZXcg bWlsbGlzZWNvbmRzIGFmdGVyDQo+ID4gICAucXVldWVfcnEoKSByZXR1cm5lZCBCTEtfU1RTX1JF U09VUkNFIHRoYXQgdGhlIGNvbmRpdGlvbiB0aGF0IGNhdXNlZA0KPiA+ICAgaXQgdG8gcmV0dXJu IEJMS19TVFNfUkVTT1VSQ0UgZ2V0cyBjbGVhcmVkLiBTbyB0aGUgYWJvdmUgYXBwcm9hY2ggY2Fu DQo+ID4gICByZXN1bHQgaW4gbG9uZyBkZWxheXMgZHVyaW5nIHdoaWNoIGl0IHdpbGwgc2VlbSBs aWtlIHRoZSBxdWV1ZSBnb3QNCj4gPiAgIHN0dWNrLiBBZGRpdGlvbmFsbHksIEkgdGhpbmsgdGhh dCB0aGUgYmxvY2sgZHJpdmVyIHNob3VsZCBkZWNpZGUgaG93DQo+ID4gICBsb25nIGl0IHRha2Vz IGJlZm9yZSBhIHF1ZXVlIGlzIHJlcnVuIGFuZCBub3QgdGhlIGJsb2NrIGxheWVyIGNvcmUuDQo+ IA0KPiBTbyBjb25maWd1cmUgcS0+cnFfdGltZW91dCB0byBiZSBzaG9ydGVyPyAgV2hpY2ggaXMg Y29uZmlndXJhYmxlIHRob3VnaA0KPiBibGtfbXFfdGFnX3NldCdzICd0aW1lb3V0JyBtZW1iZXIu ICBJdCBhcHBhcmVudGx5IGRlZmF1bHRzIHRvIDMwICogSFouDQo+IA0KPiBUaGF0IGlzIHRoZSBw cm9ibGVtIHdpdGggdGltZW91dHMsIHRoZXJlIGlzIGdlbmVyYWxseSBubyBvbmUgc2l6ZSBmaXRz DQo+IGFsbC4NCg0KU29ycnkgYnV0IEkgdGhpbmsgdGhhdCB3b3VsZCBiZSB3cm9uZy4gVGhlIGRl bGF5IGFmdGVyIHdoaWNoIGEgcXVldWUgaXMgcmVydW4NCnNob3VsZCBub3QgYmUgY291cGxlZCB0 byB0aGUgcmVxdWVzdCB0aW1lb3V0LiBUaGVzZSB0d28gc2hvdWxkIGJlIGluZGVwZW5kZW50Lg0K DQo+ID4gLSBUaGUgbG9ja3VwIHRoYXQgSSByZXBvcnRlZCBvbmx5IG9jY3VycyB3aXRoIHRoZSBk bSBkcml2ZXIgYnV0IG5vdCBhbnkNCj4gPiAgIG90aGVyIGJsb2NrIGRyaXZlci4gU28gd2h5IHRv IG1vZGlmeSB0aGUgYmxvY2sgbGF5ZXIgY29yZSBzaW5jZSB0aGlzDQo+ID4gICBjYW4gYmUgZml4 ZWQgYnkgbW9kaWZ5aW5nIHRoZSBkbSBkcml2ZXI/DQo+IA0KPiBIYXJkIHRvIGtub3cgaXQgaXMg b25seSBETSdzIGJsay1tcSB0aGF0IGlzIGltcGFjdGVkLiAgVGhhdCBpcyB0aGUgb25seQ0KPiBi bGstbXEgZHJpdmVyIHRoYXQgeW91J3JlIHRlc3RpbmcgbGlrZSB0aGlzICh0aGF0IGlzIGFsc28g YWJsZSB0byBoYW5kbGUNCj4gZmF1bHRzLCBldGMpLg0KDQpUaGF0J3Mgbm90IGNvcnJlY3QuIEkn bSBhbHNvIHRlc3RpbmcgdGhlIFNDU0kgY29yZSwgd2hpY2ggaXMgb25lIG9mIHRoZSBtb3N0DQpj b21wbGljYXRlZCBibG9jayBkcml2ZXJzLg0KDQo+ID4gLSBBIG11Y2ggc2ltcGxlciBmaXggYW5k IGEgZml4IHRoYXQgaXMga25vd24gdG8gd29yayBleGlzdHMsIG5hbWVseQ0KPiA+ICAgaW5zZXJ0 aW5nIGEgYmxrX21xX2RlbGF5X3J1bl9od19xdWV1ZSgpIGNhbGwgaW4gdGhlIGRtIGRyaXZlci4N Cj4gDQo+IEJlY2F1c2UgeW91ciAibXVjaCBzaW1wbGVyIiBmaXggYWN0aXZlbHkgaHVydHMgcGVy Zm9ybWFuY2UsIGFzIGlzDQo+IGRldGFpbGVkIGluIHRoaXMgaGVhZGVyOg0KPiBodHRwczovL2dp dC5rZXJuZWwub3JnL3B1Yi9zY20vbGludXgva2VybmVsL2dpdC9kZXZpY2UtbWFwcGVyL2xpbnV4 LWRtLmdpdC9jb21taXQvP2g9ZG0tNC4xNiZpZD1lYzNlYWY5YTY3MzEwNmY2NjYwNjg5NmFlZDZk ZGQyMDE4MGIwMmVjDQoNCldlIGFyZSBjbG9zZSB0byB0aGUgc3RhcnQgb2YgdGhlIG1lcmdlIHdp bmRvdyBzbyBJIHRoaW5rIGl0J3MgYmV0dGVyIHRvIGZhbGwNCmJhY2sgdG8gYW4gb2xkIGFwcHJv YWNoIHRoYXQgaXMga25vd24gdG8gd29yayB0aGFuIHRvIGtlZXAgYSBuZXcgYXBwcm9hY2gNCnRo YXQgaXMga25vd24gbm90IHRvIHdvcmsuIEFkZGl0aW9uYWxseSwgdGhlIHBlcmZvcm1hbmNlIGlz c3VlIHlvdSByZWZlcnJlZA0KdG8gb25seSBhZmZlY3RzIElPUFMgYW5kIGJhbmR3aWR0aCBtb3Jl IHRoYW4gMSUgd2l0aCB0aGUgbHBmYyBkcml2ZXIgYW5kIHRoYXQNCmlzIGJlY2F1c2UgdGhlIHF1 ZXVlIGRlcHRoIGl0IHN1cHBvcnRzIGlzIG11Y2ggbG93ZXIgdGhhbiBmb3Igb3RoZXIgU0NTSSBI QkFzLA0KbmFtZWx5IDMgaW5zdGVhZCBvZiA2NC4NCg0KVGhhbmtzLA0KDQpCYXJ0Lg==