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Message-ID: <4acb6f4e-5d91-462f-a741-d7839593cbdc@kylinos.cn>
Date: Thu, 14 Mar 2024 13:42:31 +0800
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MIME-Version: 1.0
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Subject: Re: [PATCH] scsi: megaraid_sas: disabled shared host tagset feature
 by default
Content-Language: en-US
To: John Garry <john.g.garry@oracle.com>, kashyap.desai@broadcom.com,
 sumit.saxena@broadcom.com, shivasharan.srikanteshwara@broadcom.com,
 chandrakanth.patil@broadcom.com
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20240311085412.2391632-1-mengfanhui@kylinos.cn>
 <03afee77-3d5e-44fc-9e03-eec70c9cee2a@oracle.com>
From: mengfanhui <mengfanhui@kylinos.cn>
In-Reply-To: <03afee77-3d5e-44fc-9e03-eec70c9cee2a@oracle.com>
Content-Type: text/plain; charset=UTF-8
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We are analyzing the kylinos issue and found that the performance degrada=
tion caused by patch 103fbf8e4020845e4fcf63819288cedb092a3c91.
It will change the working mode of the disk, It will lead to performance =
degradation.Currently driver has provision to disable host-wide=20
tags using "host_tagset_enable" module parameter.


=E5=9C=A8 2024/3/11 17:30, John Garry =E5=86=99=E9=81=93:
> On 11/03/2024 08:54, mengfanhui wrote:
>> By default, the host_tagset_enable feature is disabled=EF=BC=8CFio per=
formance
>> has improved significantly
>>
>> fio test command:
>> sudo fio -filename=3D/fio_test -direct=3D1 -iodepth 32 -thread -rw=3Dw=
rite -ioengine=3Dlibaio
>> -bs=3D4K -size=3D5120M -runtime=3D600 -numjobs=3D$CPUN -group_reportin=
g -name=3D**.result >> **.result
>>
>> The test data results bw=C2=A0 are as follows=EF=BC=9A
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0 v6.8_kernel=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 v6.8_kernel_=
disable_host_tagset
>> 4k randwrite=C2=A0=C2=A0=C2=A0=C2=A0 375=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0 642
>> 4k randread=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 210=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 784
>> 4k=C2=A0 write=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 306=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 387
>> 4k=C2=A0 read=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 435=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 2457
>> 128k write=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 355=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0 380
>> 128k read=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 976=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 3665
>> 1M=C2=A0=C2=A0 read=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 415=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 3122
>>
>=20
> There are some huge differences in those numbers. Can you find out what=
 is going on?
>=20
>> Signed-off-by: mengfanhui <mengfanhui@kylinos.cn>
>> ---
>> =C2=A0 drivers/scsi/megaraid/megaraid_sas_base.c | 4 ++--
>> =C2=A0 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/=
megaraid/megaraid_sas_base.c
>> index 3d4f13da1ae8..da19c4c07f2f 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
>> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
>> @@ -123,9 +123,9 @@ MODULE_PARM_DESC(poll_queues, "Number of queues to=
 be use for io_uring poll mode
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 "High iops queu=
es are not allocated &\n\t\t"
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 );
>> =C2=A0 -int host_tagset_enable =3D 1;
>> +int host_tagset_enable;
>> =C2=A0 module_param(host_tagset_enable, int, 0444);
>> -MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disab=
le Default: enable(1)");
>> +MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disab=
le Default: disable(0)");
>> =C2=A0 =C2=A0 MODULE_LICENSE("GPL");
>> =C2=A0 MODULE_VERSION(MEGASAS_VERSION);
>=20