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

[Jaegeuk Kim]

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?

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