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From: John Garry <john.garry@huawei.com>
To: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>,
	Hannes Reinecke <hare@suse.com>,
	Kashyap Desai <kashyap.desai@broadcom.com>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	Christoph Hellwig <hch@lst.de>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	Sathya Prakash <sathya.prakash@broadcom.com>,
	Sreekanth Reddy <sreekanth.reddy@broadcom.com>,
	Suganath Prabu Subramani  <suganath-prabu.subramani@broadcom.com>,
	PDL-MPT-FUSIONLINUX <MPT-FusionLinux.pdl@broadcom.com>,
	chenxiang <chenxiang66@hisilicon.com>
Subject: Re: About scsi device queue depth
Date: Tue, 12 Jan 2021 17:44:14 +0000	[thread overview]
Message-ID: <9241f2fa-3143-7aae-ee21-71e31e363c9a@huawei.com> (raw)
In-Reply-To: <20210112090634.GA97446@T590>

>>>> sdev qdepth	fio number jobs* 	1	10	20
>>>> 16					1590	1654	1660
>>>> 32					1545	1646	1654
>>>> 64					1436	1085	1070
>>>> 254 (default)				1436	1070	1050
>>> What does the performance number mean? IOPS or others? What is the fio
>>> io test? random IO or sequential IO?
>> So those figures are x1K IOPs read performance; so 1590, above, is 1.59M
>> IOPs read. Here's the fio script:
>>
>> [global]
>> rw=read
>> direct=1
>> ioengine=libaio
>> iodepth=40
>> numjobs=20
>> bs=4k
>> ;size=10240000m
>> ;zero_buffers=1
>> group_reporting=1
>> ;ioscheduler=noop
>> ;cpumask=0xffe
>> ;cpus_allowed=1-47
>> ;gtod_reduce=1
>> ;iodepth_batch=2
>> ;iodepth_batch_complete=2
>> runtime=60
>> ;thread
>> loops = 10000
> Is there any effect on random read IOPS when you decrease sdev queue
> depth? For sequential IO, IO merge can be enhanced by that way.
> 

Hi Ming,

fio randread results:

fio queue depth 40
sdev qdepth	fio number jobs* 	1	10	20
8					1308K	831K	814K
16					1435K	1073K	988K
32					1438K	1065K	990K
64					1432K	1061K	1020K
254 (default)				1439K	1099K	1083K


fio queue depth 128
sdev qdepth	fio number jobs* 	1	10	20
8					1310K	860K	849K
16					1435K	1048K	958K
32					1438K	1140K	951K
64					1438K	1065K	953k
254 (default)				1439K	1140K	1056K

So randread goes in the opposite direction (to read wrt queue depth).

Thanks,
John

  parent reply	other threads:[~2021-01-12 17:46 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11 16:21 About scsi device queue depth John Garry
2021-01-11 16:40 ` James Bottomley
2021-01-11 17:11   ` John Garry
2021-01-12  6:35     ` James Bottomley
2021-01-12 10:27       ` John Garry
2021-01-12 16:40         ` Bryan Gurney
2021-01-12 16:47         ` James Bottomley
2021-01-12 17:20           ` Bryan Gurney
2021-01-11 17:31   ` Douglas Gilbert
2021-01-13  6:07   ` Martin K. Petersen
2021-01-13  6:36     ` Damien Le Moal
2021-01-12  1:42 ` Ming Lei
2021-01-12  8:56   ` John Garry
2021-01-12  9:06     ` Ming Lei
2021-01-12  9:23       ` John Garry
2021-01-12 11:44         ` Kashyap Desai
2021-01-13 12:17           ` John Garry
2021-01-13 13:34             ` Kashyap Desai
2021-01-13 15:39               ` John Garry
2021-01-12 17:44       ` John Garry [this message]
2021-01-12  7:23 ` Hannes Reinecke
2021-01-12  9:15   ` John Garry

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