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From: Chaitanya Kulkarni <chaitanyak@nvidia.com>
To: Dan Williams <dan.j.williams@intel.com>,
	Chaitanya Kulkarni <chaitanyak@nvidia.com>,
	"vishal.l.verma@intel.com" <vishal.l.verma@intel.com>,
	"dave.jiang@intel.com" <dave.jiang@intel.com>,
	"ira.weiny@intel.com" <ira.weiny@intel.com>
Cc: "nvdimm@lists.linux.dev" <nvdimm@lists.linux.dev>
Subject: Re: [PATCH 1/1] pmem: allow user to set QUEUE_FLAG_NOWAIT
Date: Sat, 13 May 2023 00:58:16 +0000	[thread overview]
Message-ID: <77b44173-d5dc-94a0-e9fd-58afd3cc7fe3@nvidia.com> (raw)
In-Reply-To: <645e8b49ca74f_1e6f29437@dwillia2-xfh.jf.intel.com.notmuch>

On 5/12/23 11:54, Dan Williams wrote:
> Chaitanya Kulkarni wrote:
>> Allow user to set the QUEUE_FLAG_NOWAIT optionally using module
>> parameter to retain the default behaviour. Also, update respective
>> allocation flags in the write path. Following are the performance
>> numbers with io_uring fio engine for random read, note that device has
>> been populated fully with randwrite workload before taking these
>> numbers :-
> Numbers look good. I see no reason for this to be optional. Just like
> the brd driver always sets NOWAIT, so should pmem.

yes, sending out v2 without mod param.

>
>> * linux-block (for-next) # grep IOPS  pmem*fio | column -t
>>
>> nowait-off-1.fio:  read:  IOPS=3968k,  BW=15.1GiB/s
>> nowait-off-2.fio:  read:  IOPS=4084k,  BW=15.6GiB/s
>> nowait-off-3.fio:  read:  IOPS=3995k,  BW=15.2GiB/s
>>
>> nowait-on-1.fio:   read:  IOPS=5909k,  BW=22.5GiB/s
>> nowait-on-2.fio:   read:  IOPS=5997k,  BW=22.9GiB/s
>> nowait-on-3.fio:   read:  IOPS=6006k,  BW=22.9GiB/s
>>
>> * linux-block (for-next) # grep cpu  pmem*fio | column -t
>>
>> nowait-off-1.fio:  cpu  :  usr=6.38%,   sys=31.37%,  ctx=220427659
>> nowait-off-2.fio:  cpu  :  usr=6.19%,   sys=31.45%,  ctx=229825635
>> nowait-off-3.fio:  cpu  :  usr=6.17%,   sys=31.22%,  ctx=221896158
>>
>> nowait-on-1.fio:  cpu  :  usr=10.56%,  sys=87.82%,  ctx=24730
>> nowait-on-2.fio:  cpu  :  usr=9.92%,   sys=88.36%,  ctx=23427
>> nowait-on-3.fio:  cpu  :  usr=9.85%,   sys=89.04%,  ctx=23237
>>
>> * linux-block (for-next) # grep slat  pmem*fio | column -t
>> nowait-off-1.fio:  slat  (nsec):  min=431,   max=50423k,  avg=9424.06
>> nowait-off-2.fio:  slat  (nsec):  min=420,   max=35992k,  avg=9193.94
>> nowait-off-3.fio:  slat  (nsec):  min=430,   max=40737k,  avg=9244.24
>>
>> nowait-on-1.fio:   slat  (nsec):  min=1232,  max=40098k,  avg=7518.60
>> nowait-on-2.fio:   slat  (nsec):  min=1303,  max=52107k,  avg=7423.37
>> nowait-on-3.fio:   slat  (nsec):  min=1123,  max=40193k,  avg=7409.08
> Any thoughts on why min latency went up?

really not sure why, will need some more time to investigate that ..

-ck



  reply	other threads:[~2023-05-13  0:58 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-12 10:43 [PATCH 0/1] pmem: allow user to set QUEUE_FLAG_NOWAIT Chaitanya Kulkarni
2023-05-12 10:43 ` [PATCH 1/1] " Chaitanya Kulkarni
2023-05-12 17:14   ` Ira Weiny
2023-05-13  0:56     ` Chaitanya Kulkarni
2023-05-12 18:54   ` Dan Williams
2023-05-13  0:58     ` Chaitanya Kulkarni [this message]
2023-05-15 19:54   ` Jane Chu
2023-05-15 23:53     ` Dan Williams
2023-05-16 17:58       ` Jane Chu
2023-05-12 13:29 ` [PATCH 0/1] " Christoph Hellwig
2023-05-13  0:54   ` Chaitanya Kulkarni

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