Re: [PATCH V3 1/8] scsi: hpsa: fix selection of reply queue

[Laurence Oberman <loberman@redhat.com>]

On Fri, 2018-03-02 at 15:03 +0000, Don Brace wrote:
> > -----Original Message-----
> > From: Laurence Oberman [mailto:loberman@redhat.com]
> > Sent: Friday, March 02, 2018 8:09 AM
> > To: Ming Lei <ming.lei@redhat.com>
> > Cc: Don Brace <don.brace@microsemi.com>; Jens Axboe <axboe@kernel.d
> > k>;
> > linux-block@vger.kernel.org; Christoph Hellwig <hch@infradead.org>;
> > Mike
> > Snitzer <snitzer@redhat.com>; linux-scsi@vger.kernel.org; Hannes
> > Reinecke
> > <hare@suse.de>; Arun Easi <arun.easi@cavium.com>; Omar Sandoval
> > <osandov@fb.com>; Martin K . Petersen <martin.petersen@oracle.com>;
> > James
> > Bottomley <james.bottomley@hansenpartnership.com>; Christoph
> > Hellwig
> > <hch@lst.de>; Kashyap Desai <kashyap.desai@broadcom.com>; Peter
> > Rivera
> > <peter.rivera@broadcom.com>; Meelis Roos <mroos@linux.ee>
> > Subject: Re: [PATCH V3 1/8] scsi: hpsa: fix selection of reply
> > queue
> > 
> > EXTERNAL EMAIL
> > 
> > 
> > On Fri, 2018-03-02 at 10:16 +0800, Ming Lei wrote:
> > > On Thu, Mar 01, 2018 at 04:19:34PM -0500, Laurence Oberman wrote:
> > > > On Thu, 2018-03-01 at 14:01 -0500, Laurence Oberman wrote:
> > > > > On Thu, 2018-03-01 at 16:18 +0000, Don Brace wrote:
> > > > > > > -----Original Message-----
> > > > > > > From: Ming Lei [mailto:ming.lei@redhat.com]
> > > > > > > Sent: Tuesday, February 27, 2018 4:08 AM
> > > > > > > To: Jens Axboe <axboe@kernel.dk>; linux-block@vger.kernel
> > > > > > > .org
> > > > > > > ;
> > > > > > > Christoph
> > > > > > > Hellwig <hch@infradead.org>; Mike Snitzer <snitzer@redhat
> > > > > > > .com
> > > > > > > > 
> > > > > > > 
> > > > > > > Cc: linux-scsi@vger.kernel.org; Hannes Reinecke <hare@sus
> > > > > > > e.de
> > > > > > > > ;
> > > > > > > 
> > > > > > > Arun Easi
> > > > > > > <arun.easi@cavium.com>; Omar Sandoval <osandov@fb.com>;
> > > > > > > Martin K
> > > > > > > .
> > > > > > > Petersen <martin.petersen@oracle.com>; James Bottomley
> > > > > > > <james.bottomley@hansenpartnership.com>; Christoph
> > > > > > > Hellwig <h
> > > > > > > ch@l
> > > > > > > st
> > > > > > > .de>;
> > > > > > > Don Brace <don.brace@microsemi.com>; Kashyap Desai
> > > > > > > <kashyap.desai@broadcom.com>; Peter Rivera <peter.rivera@
> > > > > > > broa
> > > > > > > dcom
> > > > > > > .c
> > > > > > > om>;
> > > > > > > Laurence Oberman <loberman@redhat.com>; Ming Lei
> > > > > > > <ming.lei@redhat.com>; Meelis Roos <mroos@linux.ee>
> > > > > > > Subject: [PATCH V3 1/8] scsi: hpsa: fix selection of
> > > > > > > reply
> > > > > > > queue
> > > > > > > 
> > > 
> > > Seems Don run into IO failure without blk-mq, could you run your
> > > tests again
> > > in legacy mode?
> > > 
> > > Thanks,
> > > Ming
> > 
> > Hello Ming
> > I ran multiple passes on Legacy and still see no issues in my test
> > bed
> > 
> > BOOT_IMAGE=/vmlinuz-4.16.0-rc2.ming+ root=UUID=43f86d71-b1bf-4789-
> > a28e-
> > 21c6ddc90195 ro crashkernel=256M@64M log_buf_len=64M
> > console=ttyS1,115200n8
> > 
> > HEAD of the git kernel I am using
> > 
> > 694e16f scsi: megaraid: improve scsi_mq performance via
> > .host_tagset
> > 793686c scsi: hpsa: improve scsi_mq performance via .host_tagset
> > 60d5b36 block: null_blk: introduce module parameter of
> > 'g_host_tags'
> > 8847067 scsi: Add template flag 'host_tagset'
> > a8fbdd6 blk-mq: introduce BLK_MQ_F_HOST_TAGS
> > 4710fab blk-mq: introduce 'start_tag' field to 'struct blk_mq_tags'
> > 09bb153 scsi: megaraid_sas: fix selection of reply queue
> > 52700d8 scsi: hpsa: fix selection of reply queue
> 
> I checkout out Linus's tree (4.16.0-rc3+) and re-applied the above
> patches.
> I  and have been running 24 hours with no issues.
> Evidently my forked copy was corrupted. 
> 
> So, my I/O testing has gone well. 
> 
> I'll run some performance numbers next.
> 
> Thanks,
> Don

Unless Kashyap is not happy we need to consider getting this in to
Linus now because we are seeing HPE servers that keep hanging now with
the original commit now upstream.

Kashyap, are you good with the v3 patchset or still concerned with
performance. I was getting pretty good IOPS/sec to individual SSD
drives set up as jbod devices on the megaraid_sas.

With larger I/O sizes like 1MB I was getting good MB/sec and not seeing
a measurable performance impact.

I dont have the hardware you have to mimic your configuration.

Thanks
Laurence