From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "hch@infradead.org" , "sagi@grimberg.me" , "axboe@kernel.dk" CC: "keith.busch@intel.com" , "linux-block@vger.kernel.org" , "linux-nvme@lists.infradead.org" Subject: Re: [GIT PULL] nvme update for Linux 4.14, take 2 Date: Wed, 30 Aug 2017 15:46:33 +0000 Message-ID: <1504107991.2526.16.camel@wdc.com> References: <20170829150507.rjixn6uf3id6kltx@infradead.org> <9a27048d-1252-985f-c905-b738d709b204@kernel.dk> <38ddd70f-3fec-09c0-dafb-eba1e8f9cc18@grimberg.me> <1504106914.2526.5.camel@wdc.com> In-Reply-To: Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 List-ID: T24gV2VkLCAyMDE3LTA4LTMwIGF0IDE4OjMzICswMzAwLCBTYWdpIEdyaW1iZXJnIHdyb3RlOg0K PiA+ID4gSSBqdXN0IHJlYWxpemVkIHRoYXQgcGF0Y2g6DQo+ID4gPiAtLQ0KPiA+ID4gY29tbWl0 IGQzNTJhZTIwNWQ4YjA1ZjNmNzU1OGQxMGY0NzRkODQzNjU4MWIzZTINCj4gPiA+IEF1dGhvcjog QmFydCBWYW4gQXNzY2hlIDxiYXJ0LnZhbmFzc2NoZUB3ZGMuY29tPg0KPiA+ID4gRGF0ZTogICBU aHUgQXVnIDE3IDE2OjIzOjAzIDIwMTcgLTA3MDANCj4gPiA+IA0KPiA+ID4gICAgICAgYmxrLW1x OiBNYWtlIGJsa19tcV9yZWluaXRfdGFnc2V0KCkgY2FsbHMgZWFzaWVyIHRvIHJlYWQNCj4gPiA+ IA0KPiA+ID4gICAgICAgU2luY2UgYmxrX21xX29wcy5yZWluaXRfcmVxdWVzdCBpcyBvbmx5IGNh bGxlZCBmcm9tIGluc2lkZQ0KPiA+ID4gICAgICAgYmxrX21xX3JlaW5pdF90YWdzZXQoKSwgbWFr ZSB0aGlzIGZ1bmN0aW9uIHBvaW50ZXIgYW4gYXJndW1lbnQgb2YNCj4gPiA+ICAgICAgIGJsa19t cV9yZWluaXRfdGFnc2V0KCkgaW5zdGVhZCBvZiBhIG1lbWJlciBvZiBzdHJ1Y3QgYmxrX21xX29w cy4NCj4gPiA+ICAgICAgIFRoaXMgcGF0Y2ggZG9lcyBub3QgY2hhbmdlIGFueSBmdW5jdGlvbmFs aXR5IGJ1dCBtYWtlcw0KPiA+ID4gICAgICAgYmxrX21xX3JlaW5pdF90YWdzZXQoKSBjYWxscyBl YXNpZXIgdG8gcmVhZCBhbmQgdG8gYW5hbHl6ZS4NCj4gPiA+IC0tDQo+ID4gPiANCj4gPiA+IE1h a2VzIGl0IGltcG9zc2libGUgZm9yIG1lIHRvIG1vdmUgY29udHJvbGxlciByZXNldCBmbG93IHRv DQo+ID4gPiBudm1lLWNvcmUgd2l0aG91dCBhZGRpbmcgYSB0cmFtcG9saW5lIChhcyB0aGUgcmVp bml0X3JlcXVlc3QNCj4gPiA+IGlzIHRyYW5zcG9ydCBzcGVjaWZpYykuLi4NCj4gPiANCj4gPiBI ZWxsbyBTYWdpLA0KPiA+IA0KPiA+IFNvcnJ5IGJ1dCBJIGRvdWJ0IHRoYXQgdGhhdCBwYXRjaCBt YWtlcyBpdCAiaW1wb3NzaWJsZSIgdG8gbW92ZSBjb250cm9sbGVyDQo+ID4gcmVzZXQgZmxvdyB0 byB0aGUgTlZNZSBjb3JlLiBUaGVyZSBhcmUgYWxyZWFkeSBzZXZlcmFsIGZ1bmN0aW9uIHBvaW50 ZXJzIGluDQo+ID4gdGhlIG52bWVfY3RybF9vcHMgZGF0YSBzdHJ1Y3R1cmUgYW5kIHRoZXJlIGlz IG9uZSBzdWNoIGRhdGEgc3RydWN0dXJlIHBlcg0KPiA+IHRyYW5zcG9ydC4gSGFkIHlvdSBhbHJl YWR5IGNvbnNpZGVyZWQgdG8gYWRkIGEgZnVuY3Rpb24gcG9pbnRlciB0byB0aGF0DQo+ID4gc3Ry dWN0dXJlPw0KPiANCj4gSSBoYXZlLCB0aGF0J3MgdGhlIHRyYW1wb2xpbmUgZnVuY3Rpb24gdGhh dCBJIHdhcyByZWZlcnJpbmcgdG8sIGl0IGZlZWxzDQo+IGEgYml0IGZ1bm55IHRvIGhhdmUgYWEg bnZtZSBjb3JlIGZ1bmN0aW9uIHRoYXQgd291bGQgbG9vayBsaWtlOg0KPiANCj4gaW50IG52bWVf cmVpbml0X3JlcXVlc3QoKQ0KPiB7DQo+IAlyZXR1cm4gY3RybC0+b3BzLT5yZWluaXRfcmVxdWVz dCgpDQo+IH0NCj4gDQo+IEkgY2FuIGVhc2lseSBkbyB0aGF0LCBidXQgZG9lc24ndCBpdCBkZWZl YXQgdGhlIHB1cnBvc2Ugb2YgYmxrX21xX29wcz8NCg0KSSBkb24ndCB0aGluayBzby4gUmVxdWVz dCByZWluaXRpYWxpemF0aW9uIGlzIGFuIE5WTWUgY29uY2VwdCB0aGF0IGlzIG5vdCB1c2VkDQpi eSBhbnkgb3RoZXIgYmxvY2sgZHJpdmVyLCBzbyB3aHkgc2hvdWxkIHRoZSBwb2ludGVyIHRvIHRo ZSByZWluaXRpYWxpemF0aW9uDQpmdW5jdGlvbiBleGlzdCBpbiBibGtfbXFfb3BzPw0KDQpCYXJ0 Lg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart.VanAssche@wdc.com (Bart Van Assche) Date: Wed, 30 Aug 2017 15:46:33 +0000 Subject: [GIT PULL] nvme update for Linux 4.14, take 2 In-Reply-To: References: <20170829150507.rjixn6uf3id6kltx@infradead.org> <9a27048d-1252-985f-c905-b738d709b204@kernel.dk> <38ddd70f-3fec-09c0-dafb-eba1e8f9cc18@grimberg.me> <1504106914.2526.5.camel@wdc.com> Message-ID: <1504107991.2526.16.camel@wdc.com> On Wed, 2017-08-30@18:33 +0300, Sagi Grimberg wrote: > > > I just realized that patch: > > > -- > > > commit d352ae205d8b05f3f7558d10f474d8436581b3e2 > > > Author: Bart Van Assche > > > Date: Thu Aug 17 16:23:03 2017 -0700 > > > > > > blk-mq: Make blk_mq_reinit_tagset() calls easier to read > > > > > > Since blk_mq_ops.reinit_request is only called from inside > > > blk_mq_reinit_tagset(), make this function pointer an argument of > > > blk_mq_reinit_tagset() instead of a member of struct blk_mq_ops. > > > This patch does not change any functionality but makes > > > blk_mq_reinit_tagset() calls easier to read and to analyze. > > > -- > > > > > > Makes it impossible for me to move controller reset flow to > > > nvme-core without adding a trampoline (as the reinit_request > > > is transport specific)... > > > > Hello Sagi, > > > > Sorry but I doubt that that patch makes it "impossible" to move controller > > reset flow to the NVMe core. There are already several function pointers in > > the nvme_ctrl_ops data structure and there is one such data structure per > > transport. Had you already considered to add a function pointer to that > > structure? > > I have, that's the trampoline function that I was referring to, it feels > a bit funny to have aa nvme core function that would look like: > > int nvme_reinit_request() > { > return ctrl->ops->reinit_request() > } > > I can easily do that, but doesn't it defeat the purpose of blk_mq_ops? I don't think so. Request reinitialization is an NVMe concept that is not used by any other block driver, so why should the pointer to the reinitialization function exist in blk_mq_ops? Bart.