From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ren Mingxin Subject: Re: [PATCH 0/5] scsi: Allow fast io fail without waiting through timeout Date: Wed, 22 May 2013 15:12:22 +0800 Message-ID: <519C6FD6.4090607@cn.fujitsu.com> References: <1369034103-31644-1-git-send-email-renmx@cn.fujitsu.com> <519A4716.7000001@emulex.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:36855 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751065Ab3EVHJc (ORCPT ); Wed, 22 May 2013 03:09:32 -0400 In-Reply-To: <519A4716.7000001@emulex.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Smart@emulex.com Cc: James.Bottomley@HansenPartnership.com, Nagalakshmi.Nandigama@lsi.com, Sreekanth.Reddy@lsi.com, michaelc@cs.wisc.edu, robert.w.love@intel.com, dgilbert@interlog.com, hare@suse.de, bprakash@broadcom.com, agk@redhat.com, neilb@suse.de, gregkh@linuxfoundation.org, axboe@kernel.dk, tj@kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Hi, James, On 05/20/2013 11:53 PM, James Smart wrote: > Based on the discussion recently held at LSF 2013, we are > reworking the error recovery path to address all the issues > you are mentioning. That work contradicts these patches. > So for now, these should be held off. Interesting. Can I have your general goal/idea briefly even though via a reference? Will the URL below be one you will refer to? http://lwn.net/Articles/548500 And, could I know your current progress/schedule? Especially when can we see your patches? Much appreciated! Thanks, Ren > > On 5/20/2013 3:14 AM, Ren Mingxin wrote: >> When there is a scsi command timed-out or failed, the scsi eh >> tries a thorugh recovery, which is necessary for non-redundant >> systems. However, the thorugh recovery usually takes much time, >> which is not acceptable for misson critical systems. To improve >> this latency, if we are working on a redundant system, we should >> avoid the scsi eh for its long time failing recovery, and quick >> failover to another path. >> >> This set of patches is trying to implement above. >> >> NOTE: the userland tools need to eusure the environment >> restriction, which will be implemented later. >> >> Thanks, >> Ren >> >> Ren Mingxin (5): >> scsi: rename return code FAST_IO_FAIL to FAST_IO >> FC transport: Add interface to specify fast io level for timed-out >> cmds >> SAS transport: Add interface to specify fast io level for >> timed-out cmds >> lpfc: Allow fast timed-out io recovery >> mptfusion: Allow fast timed-out io recovery >> >> drivers/message/fusion/mptscsih.c | 29 ++++++++- >> drivers/scsi/lpfc/lpfc_scsi.c | 34 ++++++++++ >> drivers/scsi/scsi_error.c | 18 ++--- >> drivers/scsi/scsi_sas_internal.h | 4 - >> drivers/scsi/scsi_transport_fc.c | 112 >> ++++++++++++++++++++++++++++++++++-- >> drivers/scsi/scsi_transport_iscsi.c | 6 - >> drivers/scsi/scsi_transport_sas.c | 103 >> ++++++++++++++++++++++++++++++++- >> include/scsi/scsi.h | 2 >> include/scsi/scsi_transport_fc.h | 11 +++ >> include/scsi/scsi_transport_sas.h | 8 ++ >> 10 files changed, 303 insertions(+), 24 deletions(-)