We are analyzing the kylinos issue and found that the performance degradation 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
tags using "host_tagset_enable" module parameter.
在 2024/3/11 17:30, John Garry 写道:
> On 11/03/2024 08:54, mengfanhui wrote:
>> By default, the host_tagset_enable feature is disabled，Fio performance
>> has improved significantly
>>
>> fio test command:
>> sudo fio -filename=/fio_test -direct=1 -iodepth 32 -thread -rw=write -ioengine=libaio
>> -bs=4K -size=5120M -runtime=600 -numjobs=$CPUN -group_reporting -name=**.result >> **.result
>>
>> The test data results bw are as follows：
>> v6.8_kernel v6.8_kernel_disable_host_tagset
>> 4k randwrite 375 642
>> 4k randread 210 784
>> 4k write 306 387
>> 4k read 435 2457
>> 128k write 355 380
>> 128k read 976 3665
>> 1M read 415 3122
>>
>
> There are some huge differences in those numbers. Can you find out what is going on?
>
>> Signed-off-by: mengfanhui <mengfanhui@xxxxxxxxxx>
>> ---
>> drivers/scsi/megaraid/megaraid_sas_base.c | 4 ++--
>> 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
>> "High iops queues are not allocated &\n\t\t"
>> );
>> -int host_tagset_enable = 1;
>> +int host_tagset_enable;
>> module_param(host_tagset_enable, int, 0444);
>> -MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disable Default: enable(1)");
>> +MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disable Default: disable(0)");
>> MODULE_LICENSE("GPL");
>> MODULE_VERSION(MEGASAS_VERSION);
>
