From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa5.hgst.iphmx.com ([216.71.153.144]:58073 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757457AbeD0QQ7 (ORCPT ); Fri, 27 Apr 2018 12:16:59 -0400 From: Bart Van Assche To: "axboe@fb.com" , "ming.lei@redhat.com" CC: "linux-block@vger.kernel.org" , "snitzer@redhat.com" , "hch@lst.de" , "martin.petersen@oracle.com" , "hare@suse.de" , "linux-scsi@vger.kernel.org" , "don.brace@microsemi.com" , "james.bottomley@hansenpartnership.com" , "osandov@fb.com" , "loberman@redhat.com" , "kashyap.desai@broadcom.com" Subject: Re: [PATCH 3/3] scsi: avoid to hold host-wide counter of host_busy for scsi_mq Date: Fri, 27 Apr 2018 16:16:48 +0000 Message-ID: References: <20180420065742.8043-1-ming.lei@redhat.com> <20180420065742.8043-4-ming.lei@redhat.com> In-Reply-To: <20180420065742.8043-4-ming.lei@redhat.com> 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 T24gRnJpLCAyMDE4LTA0LTIwIGF0IDE0OjU3ICswODAwLCBNaW5nIExlaSB3cm90ZToNCj4gK3N0 cnVjdCBzY3NpX2hvc3RfbXFfaW5fZmxpZ2h0IHsNCj4gKwlpbnQgY250Ow0KPiArfTsNCj4gKw0K PiArc3RhdGljIHZvaWQgc2NzaV9ob3N0X2NoZWNrX2luX2ZsaWdodChzdHJ1Y3QgcmVxdWVzdCAq cnEsIHZvaWQgKmRhdGEsDQo+ICsJCWJvb2wgcmVzZXJ2ZWQpDQo+ICt7DQo+ICsJc3RydWN0IHNj c2lfaG9zdF9tcV9pbl9mbGlnaHQgKmluX2ZsaWdodCA9IGRhdGE7DQo+ICsNCj4gKwlpZiAoYmxr X21xX3JlcXVlc3Rfc3RhcnRlZChycSkpDQo+ICsJCWluX2ZsaWdodC0+Y250Kys7DQo+ICt9DQo+ ICsNCj4gIC8qKg0KPiAgICogc2NzaV9ob3N0X2J1c3kgLSBSZXR1cm4gdGhlIGhvc3QgYnVzeSBj b3VudGVyDQo+ICAgKiBAc2hvc3Q6CVBvaW50ZXIgdG8gU2NzaV9Ib3N0IHRvIGluYy4NCj4gICAq Ki8NCj4gIGludCBzY3NpX2hvc3RfYnVzeShzdHJ1Y3QgU2NzaV9Ib3N0ICpzaG9zdCkNCj4gIHsN Cj4gLQlyZXR1cm4gYXRvbWljX3JlYWQoJnNob3N0LT5ob3N0X2J1c3kpOw0KPiArCXN0cnVjdCBz Y3NpX2hvc3RfbXFfaW5fZmxpZ2h0IGluX2ZsaWdodCA9IHsNCj4gKwkJLmNudCA9IDAsDQo+ICsJ fTsNCj4gKw0KPiArCWlmICghc2hvc3QtPnVzZV9ibGtfbXEpDQo+ICsJCXJldHVybiBhdG9taWNf cmVhZCgmc2hvc3QtPmhvc3RfYnVzeSk7DQo+ICsNCj4gKwlibGtfbXFfdGFnc2V0X2J1c3lfaXRl cigmc2hvc3QtPnRhZ19zZXQsIHNjc2lfaG9zdF9jaGVja19pbl9mbGlnaHQsDQo+ICsJCQkmaW5f ZmxpZ2h0KTsNCj4gKwlyZXR1cm4gaW5fZmxpZ2h0LmNudDsNCj4gIH0NCj4gIEVYUE9SVF9TWU1C T0woc2NzaV9ob3N0X2J1c3kpOw0KDQpUaGlzIHBhdGNoIGludHJvZHVjZXMgYSBzdWJ0bGUgYmVo YXZpb3IgY2hhbmdlIHRoYXQgaGFzIG5vdCBiZWVuIGV4cGxhaW5lZA0KaW4gdGhlIGNvbW1pdCBt ZXNzYWdlLiBJZiBhIFNDU0kgcmVxdWVzdCBnZXRzIHJlcXVldWVkIHRoYXQgcmVzdWx0cyBpbiBh DQpkZWNyZWFzZSBvZiB0aGUgLmhvc3RfYnVzeSBjb3VudGVyIGJ5IHNjc2lfZGV2aWNlX3VuYnVz eSgpIGJlZm9yZSB0aGUgcmVxdWVzdA0KaXMgcmVxdWV1ZWQgYW5kIGFuIGluY3JlYXNlIG9mIHRo ZSBob3N0X2J1c3kgY291bnRlciB3aGVuIHNjc2lfcXVldWVfcnEoKSBpcw0KY2FsbGVkIGFnYWlu LiBEdXJpbmcgdGhhdCB0aW1lIHN1Y2ggcmVxdWVzdHMgaGF2ZSB0aGUgc3RhdGUgTVFfUlFfQ09N UExFVEUgYW5kDQpoZW5jZSBibGtfbXFfcmVxdWVzdF9zdGFydGVkKCkgd2lsbCByZXR1cm4gdHJ1 ZSBhbmQgc2NzaV9ob3N0X2NoZWNrX2luX2ZsaWdodCgpDQp3aWxsIGluY2x1ZGUgdGhlc2UgcmVx dWVzdHMuIEluIG90aGVyIHdvcmRzLCB0aGlzIHBhdGNoIGludHJvZHVjZXMgYSBzdWJ0bGUNCmJl aGF2aW9yIGNoYW5nZSB0aGF0IGhhcyBub3QgYmVlbiBleHBsYWluZWQgaW4gdGhlIGNvbW1pdCBt ZXNzYWdlLiBIZW5jZSBJJ20NCmRvdWJ0IHRoYXQgdGhpcyBjaGFuZ2UgaXMgY29ycmVjdC4NCg0K QmFydC4NCg0KDQoNCg==