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From: Ming Lei <ming.lei@redhat.com>
To: Hannes Reinecke <hare@suse.de>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>,
	Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org,
	Christoph Hellwig <hch@infradead.org>,
	Mike Snitzer <snitzer@redhat.com>,
	linux-scsi@vger.kernel.org, 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>,
	Don Brace <don.brace@microsemi.com>,
	Peter Rivera <peter.rivera@broadcom.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Laurence Oberman <loberman@redhat.com>
Subject: Re: [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq
Date: Wed, 7 Feb 2018 20:23:02 +0800	[thread overview]
Message-ID: <20180207122257.GA16633@ming.t460p> (raw)
In-Reply-To: <4c934478-a9c1-2f66-83f2-982b85c4e6cc@suse.de>

On Wed, Feb 07, 2018 at 07:50:21AM +0100, Hannes Reinecke wrote:
> Hi all,
> 
> [ .. ]
> >>
> >> Could you share us your patch for enabling global_tags/MQ on
> > megaraid_sas
> >> so that I can reproduce your test?
> >>
> >>> See below perf top data. "bt_iter" is consuming 4 times more CPU.
> >>
> >> Could you share us what the IOPS/CPU utilization effect is after
> > applying the
> >> patch V2? And your test script?
> > Regarding CPU utilization, I need to test one more time. Currently system
> > is in used.
> > 
> > I run below fio test on total 24 SSDs expander attached.
> > 
> > numactl -N 1 fio jbod.fio --rw=randread --iodepth=64 --bs=4k
> > --ioengine=libaio --rw=randread
> > 
> > Performance dropped from 1.6 M IOPs to 770K IOPs.
> > 
> This is basically what we've seen with earlier iterations.

Hi Hannes,

As I mentioned in another mail[1], Kashyap's patch has a big issue, which
causes only reply queue 0 used.

[1] https://marc.info/?l=linux-scsi&m=151793204014631&w=2

So could you guys run your performance test again after fixing the patch?


Thanks,
Ming

  reply	other threads:[~2018-02-07 12:23 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-03  4:21 [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq Ming Lei
2018-02-03  4:21 ` [PATCH 1/5] blk-mq: tags: define several fields of tags as pointer Ming Lei
2018-02-05  6:57   ` Hannes Reinecke
2018-02-08 17:34   ` Bart Van Assche
2018-02-03  4:21 ` [PATCH 2/5] blk-mq: introduce BLK_MQ_F_GLOBAL_TAGS Ming Lei
2018-02-05  6:54   ` Hannes Reinecke
2018-02-05 10:35     ` Ming Lei
2018-02-03  4:21 ` [PATCH 3/5] block: null_blk: introduce module parameter of 'g_global_tags' Ming Lei
2018-02-05  6:54   ` Hannes Reinecke
2018-02-03  4:21 ` [PATCH 4/5] scsi: introduce force_blk_mq Ming Lei
2018-02-05  6:57   ` Hannes Reinecke
2018-02-03  4:21 ` [PATCH 5/5] scsi: virtio_scsi: fix IO hang by irq vector automatic affinity Ming Lei
2018-02-05  6:57   ` Hannes Reinecke
2018-02-05  6:58 ` [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce force_blk_mq Hannes Reinecke
2018-02-05  7:05   ` Kashyap Desai
2018-02-05 10:17     ` Ming Lei
2018-02-06  6:03       ` Kashyap Desai
2018-02-06  8:04         ` Ming Lei
2018-02-06 11:29           ` Kashyap Desai
2018-02-06 12:31             ` Ming Lei
2018-02-06 14:27               ` Kashyap Desai
2018-02-06 15:46                 ` Ming Lei
2018-02-07  6:50                 ` Hannes Reinecke
2018-02-07 12:23                   ` Ming Lei [this message]
2018-02-07 14:14                     ` Kashyap Desai
2018-02-08  1:23                       ` Ming Lei
2018-02-08  7:00                       ` Hannes Reinecke
2018-02-08 16:53                         ` Ming Lei
2018-02-09  4:58                           ` Kashyap Desai
2018-02-09  5:31                             ` Ming Lei
2018-02-09  8:42                               ` Kashyap Desai
2018-02-10  1:01                                 ` Ming Lei
2018-02-11  5:31                                   ` Ming Lei
2018-02-12 18:35                                     ` Kashyap Desai
2018-02-13  0:40                                       ` Ming Lei
2018-02-14  6:28                                         ` Kashyap Desai
2018-02-05 10:23   ` Ming Lei

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