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From: Kashyap Desai <kashyap.desai@broadcom.com>
To: Ming Lei <ming.lei@redhat.com>, Hannes Reinecke <hare@suse.de>
Cc: 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 19:44:04 +0530	[thread overview]
Message-ID: <95b8ea33c79b84188e4a54b4e5fcd7b6@mail.gmail.com> (raw)
In-Reply-To: <20180207122257.GA16633@ming.t460p>

> -----Original Message-----
> From: Ming Lei [mailto:ming.lei@redhat.com]
> Sent: Wednesday, February 7, 2018 5:53 PM
> To: Hannes Reinecke
> Cc: Kashyap Desai; Jens Axboe; linux-block@vger.kernel.org; Christoph
> Hellwig; Mike Snitzer; linux-scsi@vger.kernel.org; Arun Easi; Omar
Sandoval;
> Martin K . Petersen; James Bottomley; Christoph Hellwig; Don Brace;
Peter
> Rivera; Paolo Bonzini; Laurence Oberman
> Subject: Re: [PATCH 0/5] blk-mq/scsi-mq: support global tags & introduce
> force_blk_mq
>
> 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?

Ming -

I tried after change you requested.  Performance drop is still unresolved.
>From 1.6 M IOPS to 770K IOPS.

See below data. All 24 reply queue is in used correctly.

IRQs / 1 second(s)
IRQ#  TOTAL  NODE0   NODE1  NAME
 360  16422      0   16422  IR-PCI-MSI 70254653-edge megasas
 364  15980      0   15980  IR-PCI-MSI 70254657-edge megasas
 362  15979      0   15979  IR-PCI-MSI 70254655-edge megasas
 345  15696      0   15696  IR-PCI-MSI 70254638-edge megasas
 341  15659      0   15659  IR-PCI-MSI 70254634-edge megasas
 369  15656      0   15656  IR-PCI-MSI 70254662-edge megasas
 359  15650      0   15650  IR-PCI-MSI 70254652-edge megasas
 358  15596      0   15596  IR-PCI-MSI 70254651-edge megasas
 350  15574      0   15574  IR-PCI-MSI 70254643-edge megasas
 342  15532      0   15532  IR-PCI-MSI 70254635-edge megasas
 344  15527      0   15527  IR-PCI-MSI 70254637-edge megasas
 346  15485      0   15485  IR-PCI-MSI 70254639-edge megasas
 361  15482      0   15482  IR-PCI-MSI 70254654-edge megasas
 348  15467      0   15467  IR-PCI-MSI 70254641-edge megasas
 368  15463      0   15463  IR-PCI-MSI 70254661-edge megasas
 354  15420      0   15420  IR-PCI-MSI 70254647-edge megasas
 351  15378      0   15378  IR-PCI-MSI 70254644-edge megasas
 352  15377      0   15377  IR-PCI-MSI 70254645-edge megasas
 356  15348      0   15348  IR-PCI-MSI 70254649-edge megasas
 337  15344      0   15344  IR-PCI-MSI 70254630-edge megasas
 343  15320      0   15320  IR-PCI-MSI 70254636-edge megasas
 355  15266      0   15266  IR-PCI-MSI 70254648-edge megasas
 335  15247      0   15247  IR-PCI-MSI 70254628-edge megasas
 363  15233      0   15233  IR-PCI-MSI 70254656-edge megasas


Average:        CPU      %usr     %nice      %sys   %iowait    %steal
%irq     %soft    %guest    %gnice     %idle
Average:         18      3.80      0.00     14.78     10.08      0.00
0.00      4.01      0.00      0.00     67.33
Average:         19      3.26      0.00     15.35     10.62      0.00
0.00      4.03      0.00      0.00     66.74
Average:         20      3.42      0.00     14.57     10.67      0.00
0.00      3.84      0.00      0.00     67.50
Average:         21      3.19      0.00     15.60     10.75      0.00
0.00      4.16      0.00      0.00     66.30
Average:         22      3.58      0.00     15.15     10.66      0.00
0.00      3.51      0.00      0.00     67.11
Average:         23      3.34      0.00     15.36     10.63      0.00
0.00      4.17      0.00      0.00     66.50
Average:         24      3.50      0.00     14.58     10.93      0.00
0.00      3.85      0.00      0.00     67.13
Average:         25      3.20      0.00     14.68     10.86      0.00
0.00      4.31      0.00      0.00     66.95
Average:         26      3.27      0.00     14.80     10.70      0.00
0.00      3.68      0.00      0.00     67.55
Average:         27      3.58      0.00     15.36     10.80      0.00
0.00      3.79      0.00      0.00     66.48
Average:         28      3.46      0.00     15.17     10.46      0.00
0.00      3.32      0.00      0.00     67.59
Average:         29      3.34      0.00     14.42     10.72      0.00
0.00      3.34      0.00      0.00     68.18
Average:         30      3.34      0.00     15.08     10.70      0.00
0.00      3.89      0.00      0.00     66.99
Average:         31      3.26      0.00     15.33     10.47      0.00
0.00      3.33      0.00      0.00     67.61
Average:         32      3.21      0.00     14.80     10.61      0.00
0.00      3.70      0.00      0.00     67.67
Average:         33      3.40      0.00     13.88     10.55      0.00
0.00      4.02      0.00      0.00     68.15
Average:         34      3.74      0.00     17.41     10.61      0.00
0.00      4.51      0.00      0.00     63.73
Average:         35      3.35      0.00     14.37     10.74      0.00
0.00      3.84      0.00      0.00     67.71
Average:         36      0.54      0.00      1.77      0.00      0.00
0.00      0.00      0.00      0.00     97.69
..
Average:         54      3.60      0.00     15.17     10.39      0.00
0.00      4.22      0.00      0.00     66.62
Average:         55      3.33      0.00     14.85     10.55      0.00
0.00      3.96      0.00      0.00     67.31
Average:         56      3.40      0.00     15.19     10.54      0.00
0.00      3.74      0.00      0.00     67.13
Average:         57      3.41      0.00     13.98     10.78      0.00
0.00      4.10      0.00      0.00     67.73
Average:         58      3.32      0.00     15.16     10.52      0.00
0.00      4.01      0.00      0.00     66.99
Average:         59      3.17      0.00     15.80     10.35      0.00
0.00      3.86      0.00      0.00     66.80
Average:         60      3.00      0.00     14.63     10.59      0.00
0.00      3.97      0.00      0.00     67.80
Average:         61      3.34      0.00     14.70     10.66      0.00
0.00      4.32      0.00      0.00     66.97
Average:         62      3.34      0.00     15.29     10.56      0.00
0.00      3.89      0.00      0.00     66.92
Average:         63      3.29      0.00     14.51     10.72      0.00
0.00      3.85      0.00      0.00     67.62
Average:         64      3.48      0.00     15.31     10.65      0.00
0.00      3.97      0.00      0.00     66.60
Average:         65      3.34      0.00     14.36     10.80      0.00
0.00      4.11      0.00      0.00     67.39
Average:         66      3.13      0.00     14.94     10.70      0.00
0.00      4.10      0.00      0.00     67.13
Average:         67      3.06      0.00     15.56     10.69      0.00
0.00      3.82      0.00      0.00     66.88
Average:         68      3.33      0.00     14.98     10.61      0.00
0.00      3.81      0.00      0.00     67.27
Average:         69      3.20      0.00     15.43     10.70      0.00
0.00      3.82      0.00      0.00     66.85
Average:         70      3.34      0.00     17.14     10.59      0.00
0.00      3.00      0.00      0.00     65.92
Average:         71      3.41      0.00     14.94     10.56      0.00
0.00      3.41      0.00      0.00     67.69

Perf top -

  64.33%  [kernel]            [k] bt_iter
   4.86%  [kernel]            [k] blk_mq_queue_tag_busy_iter
   4.23%  [kernel]            [k] _find_next_bit
   2.40%  [kernel]            [k] native_queued_spin_lock_slowpath
   1.09%  [kernel]            [k] sbitmap_any_bit_set
   0.71%  [kernel]            [k] sbitmap_queue_clear
   0.63%  [kernel]            [k] find_next_bit
   0.54%  [kernel]            [k] _raw_spin_lock_irqsave

>
>
> Thanks,
> Ming

  reply	other threads:[~2018-02-07 14:14 UTC|newest]

Thread overview: 39+ 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
2018-02-08 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  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
2018-02-07 14:14                     ` Kashyap Desai [this message]
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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