Re: [f2fs-dev] [PATCH] f2fs: introduce sysfs/data_io_flag to attach REQ_META/FUA

[Chao Yu]

On 2020/4/9 10:28, Jaegeuk Kim wrote:
> On 04/09, Chao Yu wrote:
>> On 2020/4/9 10:20, Jaegeuk Kim wrote:
>>> On 04/07, Chao Yu wrote:
>>>> On 2020/4/7 10:59, Jaegeuk Kim wrote:
>>>>> On 04/07, Chao Yu wrote:
>>>>>> On 2020/4/4 0:12, Jaegeuk Kim wrote:
>>>>>>> This patch introduces a way to attach REQ_META/FUA explicitly
>>>>>>> to all the data writes given temperature.
>>>>>>>
>>>>>>> -> attach REQ_FUA to Hot Data writes
>>>>>>>
>>>>>>> -> attach REQ_FUA to Hot|Warm Data writes
>>>>>>>
>>>>>>> -> attach REQ_FUA to Hot|Warm|Cold Data writes
>>>>>>>
>>>>>>> -> attach REQ_FUA to Hot|Warm|Cold Data writes as well as
>>>>>>>           REQ_META to Hot Data writes
>>>>>>
>>>>>> Out of curiosity, what scenario it is used for?
>>>>>
>>>>> It's testing purpose to compare the bandwidths per different IO flags.
>>>>
>>>> Thanks for the hint. :)
>>>>
>>>> As nobarrier was set in Android, so REQ_PREFLUSH will not be considered in
>>>> this sysfs interface?
>>>
>>> I don't see any diff on performance, so not interesting. :)
>>
>> I doubt it may has diff on non-ufs/emmc device? just guess.
> 
> I don't have any data on emmc, so maybe. Which case do we send REQ_PREFLUSH?

fsync w/ barrier mount option.

> 
>>
>> Thanks,
>>
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>> .
>>>>>
>>> .
>>>
> .
>