From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40284 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726267AbeHWFpB (ORCPT ); Thu, 23 Aug 2018 01:45:01 -0400 Date: Thu, 23 Aug 2018 10:17:25 +0800 From: Ming Lei To: Ben Hutchings Cc: Ricardo Ribalda Delgado , Ming Lei , linux-block@vger.kernel.org Subject: Re: blk-mq 5-8 times slower for bmap-tools Message-ID: <20180823021719.GA10464@ming.t460p> References: <20180820083032.GA24522@ming.t460p> <526e40ca8f426252377be21f935ddcdec93cb197.camel@decadent.org.uk> <20180822220220.GA8846@ming.t460p> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Thu, Aug 23, 2018 at 01:51:05AM +0100, Ben Hutchings wrote: > On Thu, 2018-08-23 at 06:02 +0800, Ming Lei wrote: > > On Wed, Aug 22, 2018 at 08:22:00PM +0100, Ben Hutchings wrote: > > > On Mon, 2018-08-20 at 11:04 +0200, Ricardo Ribalda Delgado wrote: > > > > Hello Ming > > > > On Mon, Aug 20, 2018 at 10:30 AM Ming Lei wrote: > > > > > > [...] > > > > > One problem found from your iostat log is that looks there is ~30sec > > > > > idle period between IO activities when blk-mq is enabled. > > > > > > > > During all the test the LED on the device was blinking. > > > > > > > > But a closer look to dmesg reveals a lot of this messages: > > > > > > > > [ 196.929811] sd 6:0:0:0: [sdb] tag#3 data cmplt err -71 uas-tag 1 > > > > inflight: CMD > > > > [ 196.929822] sd 6:0:0:0: [sdb] tag#3 CDB: Write(10) 2a 00 00 04 00 > > > > 68 00 04 00 00 > > > > [ 227.764379] sd 6:0:0:0: [sdb] tag#4 uas_eh_abort_handler 0 uas-tag > > > > 2 inflight: CMD OUT > > > > [ 227.764389] sd 6:0:0:0: [sdb] tag#4 CDB: Write(10) 2a 00 00 04 04 > > > > 68 00 04 00 00 > > > > [ 227.766555] sd 6:0:0:0: [sdb] tag#3 uas_eh_abort_handler 0 uas-tag > > > > 1 inflight: CMD > > > > [ 227.766562] sd 6:0:0:0: [sdb] tag#3 CDB: Write(10) 2a 00 00 04 00 > > > > 68 00 04 00 00 > > > > [ 227.784312] scsi host6: uas_eh_device_reset_handler start > > > > [ 227.913672] usb 2-2: reset SuperSpeed USB device number 3 using xhci_hcd > > > > [ 227.944842] scsi host6: uas_eh_device_reset_handler success > > > > [ 231.416133] sd 6:0:0:0: [sdb] tag#1 data cmplt err -71 uas-tag 10 > > > > inflight: CMD > > > > [ 231.416147] sd 6:0:0:0: [sdb] tag#1 CDB: Write(10) 2a 00 00 06 d5 > > > > e8 00 04 00 00 > > > > > > > > And they take around 30 secons (227-196) > > > > > > > > > > > > Maybe this is a hw issue? I will bring the reader home tonight and see > > > > if I can replicate the bug with my notebook > > > > > > > > > > > > > > Maybe it is related with timeout, given we had big change in v4.17 timeout code, > > > > > and we also fixed one scsi_mq timeout related issue recently, and the patch[1] has > > > > > been merged to v4.18 release already. > > > > > > > > I tried with v4.18-rc4 (latest one packaged in debian experimental) > > > > and after 3 runs, 2 were fine (27 sec), but the last one was over a > > > > minute. > > > > > > Is it possible that this is fixed by "block: really disable runtime-pm > > > for blk-mq"? > > > > > > > As I mentioned, the similar issue can be triggered in both blk-mq and > > non-blk-mq, so it shouldn't be related with runtime PM. > > > > We need our UAS guys to take a look at this issue. > > I saw that you found a problem with UAS in both modes, but Ricardo's > problem seemed to be specific to blk-mq. > Actually both are triggered when doing WRITE to UAS, and the error message is same too. So I think two problems may be same. Thanks, Ming