From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE Date: Tue, 19 Sep 2017 15:52:37 +0000 Message-ID: <1505836356.2671.21.camel@wdc.com> References: <20170915164456.9803-1-ming.lei@redhat.com> <20170915164456.9803-2-ming.lei@redhat.com> <1505498249.3420.15.camel@wdc.com> <20170917124000.GB6289@ming.t460p> <1505747894.2685.6.camel@wdc.com> <20170919054308.GA2517@ming.t460p> <20170919154823.GA22809@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170919154823.GA22809@redhat.com> Content-Language: en-US Content-ID: <25B5CE69171FD7468AA8059F64742797@namprd04.prod.outlook.com> Sender: linux-scsi-owner@vger.kernel.org To: "snitzer@redhat.com" , "ming.lei@redhat.com" Cc: "linux-block@vger.kernel.org" , "hch@infradead.org" , "sagi@grimberg.me" , "martin.petersen@oracle.com" , "linux-scsi@vger.kernel.org" , "axboe@fb.com" , "linux-nvme@lists.infradead.org" , "jejb@linux.vnet.ibm.com" , "loberman@redhat.com" , "dm-devel@redhat.com" List-Id: dm-devel.ids T24gVHVlLCAyMDE3LTA5LTE5IGF0IDExOjQ4IC0wNDAwLCBNaWtlIFNuaXR6ZXIgd3JvdGU6DQo+ IFRoaXMgdGhyZWFkIHByb3ZlcyB0aGF0IGl0IGlzIGRlZmluaXRlbHkgYnJpdHRsZSB0byBiZSBy ZWx5aW5nIG9uIGZpeGVkDQo+IGRlbGF5cyBsaWtlIHRoaXM6DQo+IGh0dHBzOi8vcGF0Y2h3b3Jr Lmtlcm5lbC5vcmcvcGF0Y2gvOTcwMzI0OS8NCg0KSGVsbG8gTWlrZSwNCg0KU29ycnkgYnV0IEkg dGhpbmsgdGhhdCdzIGEgbWlzaW50ZXJwcmV0YXRpb24gb2YgbXkgcGF0Y2guIEkgY2FtZSB1cCB3 aXRoIHRoYXQNCnBhdGNoIGJlZm9yZSBJIGhhZCBmb3VuZCBhbmQgZml4ZWQgdGhlIHJvb3QgY2F1 c2Ugb2YgdGhlIGhpZ2ggc3lzdGVtIGxvYWQuDQpUaGVzZSBmaXhlcyBhcmUgdXBzdHJlYW0gKGtl cm5lbCB2NC4xMykgd2hpY2ggbWVhbnMgdGhhdCB0aGF0IHBhdGNoIGlzIG5vdw0Kb2Jzb2xldGUu DQoNCkJhcnQu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.hgst.iphmx.com ([68.232.143.124]:15346 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751097AbdISPwm (ORCPT ); Tue, 19 Sep 2017 11:52:42 -0400 From: Bart Van Assche To: "snitzer@redhat.com" , "ming.lei@redhat.com" CC: "linux-block@vger.kernel.org" , "hch@infradead.org" , "sagi@grimberg.me" , "martin.petersen@oracle.com" , "linux-scsi@vger.kernel.org" , "axboe@fb.com" , "linux-nvme@lists.infradead.org" , "jejb@linux.vnet.ibm.com" , "loberman@redhat.com" , "dm-devel@redhat.com" Subject: Re: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE Date: Tue, 19 Sep 2017 15:52:37 +0000 Message-ID: <1505836356.2671.21.camel@wdc.com> References: <20170915164456.9803-1-ming.lei@redhat.com> <20170915164456.9803-2-ming.lei@redhat.com> <1505498249.3420.15.camel@wdc.com> <20170917124000.GB6289@ming.t460p> <1505747894.2685.6.camel@wdc.com> <20170919054308.GA2517@ming.t460p> <20170919154823.GA22809@redhat.com> In-Reply-To: <20170919154823.GA22809@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 T24gVHVlLCAyMDE3LTA5LTE5IGF0IDExOjQ4IC0wNDAwLCBNaWtlIFNuaXR6ZXIgd3JvdGU6DQo+ IFRoaXMgdGhyZWFkIHByb3ZlcyB0aGF0IGl0IGlzIGRlZmluaXRlbHkgYnJpdHRsZSB0byBiZSBy ZWx5aW5nIG9uIGZpeGVkDQo+IGRlbGF5cyBsaWtlIHRoaXM6DQo+IGh0dHBzOi8vcGF0Y2h3b3Jr Lmtlcm5lbC5vcmcvcGF0Y2gvOTcwMzI0OS8NCg0KSGVsbG8gTWlrZSwNCg0KU29ycnkgYnV0IEkg dGhpbmsgdGhhdCdzIGEgbWlzaW50ZXJwcmV0YXRpb24gb2YgbXkgcGF0Y2guIEkgY2FtZSB1cCB3 aXRoIHRoYXQNCnBhdGNoIGJlZm9yZSBJIGhhZCBmb3VuZCBhbmQgZml4ZWQgdGhlIHJvb3QgY2F1 c2Ugb2YgdGhlIGhpZ2ggc3lzdGVtIGxvYWQuDQpUaGVzZSBmaXhlcyBhcmUgdXBzdHJlYW0gKGtl cm5lbCB2NC4xMykgd2hpY2ggbWVhbnMgdGhhdCB0aGF0IHBhdGNoIGlzIG5vdw0Kb2Jzb2xldGUu DQoNCkJhcnQu From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart.VanAssche@wdc.com (Bart Van Assche) Date: Tue, 19 Sep 2017 15:52:37 +0000 Subject: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE In-Reply-To: <20170919154823.GA22809@redhat.com> References: <20170915164456.9803-1-ming.lei@redhat.com> <20170915164456.9803-2-ming.lei@redhat.com> <1505498249.3420.15.camel@wdc.com> <20170917124000.GB6289@ming.t460p> <1505747894.2685.6.camel@wdc.com> <20170919054308.GA2517@ming.t460p> <20170919154823.GA22809@redhat.com> Message-ID: <1505836356.2671.21.camel@wdc.com> On Tue, 2017-09-19@11:48 -0400, Mike Snitzer wrote: > This thread proves that it is definitely brittle to be relying on fixed > delays like this: > https://patchwork.kernel.org/patch/9703249/ Hello Mike, Sorry but I think that's a misinterpretation of my patch. I came up with that patch before I had found and fixed the root cause of the high system load. These fixes are upstream (kernel v4.13) which means that that patch is now obsolete. Bart.