Re: [PATCH] ubifs: Introduce a mount option of force_atime.

[Dongsheng Yang <yangds.fnst@cn.fujitsu.com>]

On 06/08/2015 06:02 PM, Richard Weinberger wrote:
> Am 08.06.2015 um 11:54 schrieb Dongsheng Yang:
>> On 06/08/2015 05:33 PM, Richard Weinberger wrote:
>>> Am 08.06.2015 um 11:11 schrieb Dongsheng Yang:
>>>> On 06/08/2015 04:44 PM, Richard Weinberger wrote:
>>>>> Am 08.06.2015 um 10:27 schrieb Dongsheng Yang:
>>>>>> Currently, ubifs does not support access time anyway. I understand
>>>>>> that there is a overhead to update inode in each access from user.
>>>>>>
>>>>>> But for the following two reasons, I think we can make it optional
>>>>>> to user.
>>>>>>
>>>>>> (1). More and more flash storage in server are trying to use ubifs,
>>>>>> it is not only for a device such as mobile phone any more, we want
>>>>>> to use it in more and more generic way. Then we need to compete
>>>>>> with some other main filesystems. From this point, access time is
>>>>>> necessary to us, at least as a choice to user currently.
>>>>>
>>>>> Do you have a reference? I know that modern servers use a lot of SSDs
>>>>> which use internally NAND (mostly MLC and TLC).
>>>>> But which systems use RAW NAND where they would care about the atime?
>>>>
>>>> Hi Richard,
>>>>
>>>> Thanx for your quick response here.
>>>>
>>>> http://www.slideshare.net/FujitsuTS/bos-c113a-data-will-change-business-but-will-it-really-change-ict
>>>> I am not sure is that url available to you. But that's what my team is
>>>> focus on. It's about a server-using NAND device.
>>>
>>> So, you want to use UBI/UBIFS on NAND attached via PCEe?
>>> Is this SLC NAND? (UBI and UBIFS was designed with SLC in mind).
>>> MLC and TLC are a major challenge for UBI/UBIFS.
>>
>> It's SLC.
>
> Where can i get one of those? ;-)

Haha, unfortunately, it's a research project in Fujitsu lab. There is
a client, I am sorry I can't share the customer company name of it, for
this device. But I am afraid others would have to wait a long time to
get it in the market. :)
>
> Thanks,
> //richard
> .
>