Re: [PATCH 2/2] mkfs.f2fs: make the default extensions list much more sensical

[Chao Yu <yuchao0@huawei.com>]

Hi Ju Hyung,

On 2019/5/28 18:28, Ju Hyung Park wrote:
> Hi Chao,
> 
> On Tue, May 28, 2019 at 7:19 PM Chao Yu <yuchao0@huawei.com> wrote:
>> How about adding below extensions:
>>
>>         "zip",
>>         "bin",
>>         "dat",
>>         "txt",
> 
> zip is capable of random updates. I didn't add bz2 for the same reason.
> But I do agree that most users won't be constantly updating zip files.

Yup, I think the most possible case is using zip/bz2 to pack log files or for
some downloaded resources, which should be write-once file.

> 
> I personally use my Android device with zip treated as cold, but I'm
> not sure if it makes good sense to make it as the default that's
> supposed to run under various scenarios.
> 
> How much different is the random write performance from cold to hot?

We use different write policies: trigger OPU for hot data mostly, and IPU for
cold data, so performance is quite relating to the test scenario.

> 
> But I'm against the idea of adding the rest 3 extensions.
> "bin" and "dat" is way too generic. You wouldn't know if a program
> happens to heavily update files named .bin/.dat.
> 
> For txt, it won't be uncommon for a user to update it frequently.
> Moreover, most txt size is pretty small anyways.

I think your concern is right, those extensions are too common and it needs to
consider various platforms instead of just android. So, let's leave those three
extensions.

Thanks,

> 
> And finally, circling back to your original concern, we should be more
> careful adding extensions as there's a limit.>
> Thanks.
> .
>