From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCHv3 0/9] New EH command timeout handler Date: Fri, 12 Jul 2013 08:09:52 +0200 Message-ID: <51DF9DB0.7080502@suse.de> References: <1372688671-85639-1-git-send-email-hare@suse.de> <51DF82B9.8030406@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:45631 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480Ab3GLGJ4 (ORCPT ); Fri, 12 Jul 2013 02:09:56 -0400 In-Reply-To: <51DF82B9.8030406@cn.fujitsu.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Ren Mingxin Cc: James Bottomley , linux-scsi@vger.kernel.org, Ewan Milne , Bart van Assche , Joern Engel , James Smart , Roland Dreier On 07/12/2013 06:14 AM, Ren Mingxin wrote: > Hi, Hannes: >=20 > On 07/01/2013 10:24 PM, Hannes Reinecke wrote: >> With the original SCSI EH I got: >> # time dd if=3D/dev/zero of=3D/dev/dm-2 bs=3D4k count=3D4k oflag=3Dd= irect >> 4096+0 records in >> 4096+0 records out >> 16777216 bytes (17 MB) copied, 142.652 s, 118 kB/s >> >> real 2m22.657s >> user 0m0.013s >> sys 0m0.145s >> >> With this patchset I got: >> # time dd if=3D/dev/zero of=3D/dev/dm-2 bs=3D4k count=3D4k oflag=3Dd= irect >> 4096+0 records in >> 4096+0 records out >> 16777216 bytes (17 MB) copied, 52.1579 s, 322 kB/s >> >> real 0m52.163s >> user 0m0.012s >> sys 0m0.145s >> >> Test was to disable RSCN on the target port, disable the >> target port, and then start the 'dd' command as indicated. >=20 > Do you mean disabling RSCN/port is enough? I'm afraid I couldn't > reproduce the problem by your steps. Both with and without your > patchset are the same 'dd' result: 27s. Please let me know where I > neglected or mistook: >=20 > 1) I made a dm-multipath target 'dm-0' whose grouping policy was > failover; > 2) Disable RSCN/port via brocade fc switch: > SW300:root> portcfg rscnsupr 15 --enable; portDisable 15 > 3) Start the 'dd' command: > # time dd if=3D/dev/zero of=3D/dev/dm-0 bs=3D4k count=3D4k oflag=3D= direct > dd: writing `/dev/sde': Input/output error > 1+0 records in > 0+0 records out > 0 bytes (0 B) copied, 27.8588 s, 0.0 kB/s >=20 > real 0m27.860s > user 0m0.001s > sys 0m0.000s You are aware that you have to disable RSCNs on the _target_ port, right? Disabling RSCNs on the _initiator_ ports is a well-tested case, and the one which actually makes sense (and is even implemented in QLogic switches). Disabling RSCNs for the _target_ port, OTOH, has a very questionable nature (hence QLogic switches don't even allow you to do this). [ .. ] > Another question: >=20 > I also tried to produce timeouts by modifying Yasui's module(please > see APPENDIX A): > http://www.spinics.net/lists/linux-scsi/msg35091.html >=20 > But I got a bug with your this patchset by follwing steps(there was > not such bug without your patchset): >=20 > # grep lpfc_template /proc/kallsyms > ffffffffa00f9240 d lpfc_template [lpfc] > # multipath -ll > ... > mpathb (36000b5d0006a0000006a14e7000c0000) dm-1 FUJITSU,ETERNUS_DX400 > size=3D50G features=3D'1 queue_if_no_path' hwhandler=3D'0' wp=3Drw > |-+- policy=3D'round-robin 0' prio=3D130 status=3Dactive > | `- 2:0:0:1 sdf 8:80 active ready running > `-+- policy=3D'round-robin 0' prio=3D130 status=3Denabled > `- 3:0:0:1 sdh 8:112 active ready running > # insmod scsi_tmo_mod.ko param=3D0xffffffffa00f9240,2:0:0:1; time dd > if=3D/dev/zero of=3D/dev/dm-1 bs=3D4k count=3D4k oflag=3Ddirect > 4096+0 records in > 4096+0 records out > 16777216 bytes (17 MB) copied, 151.194 s, 111 kB/s >=20 > real 2m31.195s > user 0m0.004s > sys 0m0.111s >=20 > Please see logs in APPENDIX B. Do you think this bug is irrelevant to > your patchset? >=20 Hmm. No, sadly not. 'cancel_work_sync' cannot be called from an interrupt context; guess I'll need to convert it to delayed work. Thanks for testing; will be updating the patchset. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html