Release of UBIL: ubi with log

[Corentin Chary]

On Thu, Apr 1, 2010 at 1:14 PM, Brijesh Singh <brijesh.s.singh at gmail.com> wrote:
> Hi,
>
> On Wed, Mar 31, 2010 at 6:27 PM, Corentin Chary
> <corentin.chary at gmail.com> wrote:
>> On Tue, Mar 2, 2010 at 8:45 PM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
>>> On Fri, 2010-02-26 at 18:28 +0530, Brijesh Singh wrote:
>>>> Hi,
>>>>  It gives me great pleasure in sharing UBIL: ubi with log.  We have
>>>> added logging functionality to ubi for reducing mount time.
>>>> UBIL uses the "same source base of UBI". The logging functionality can
>>>> be added or removed at compile time using "make menuconfig option".
>>>>
>>>> We have seen mount time reduction of 50% in 1GB NAND. We are expecting
>>>> even better results for larger flash memories.
>>>>
>>>> The source code of UBIL can be found in the following git tree:
>>>> http://git.infradead.org/users/brijesh/ubi-2.6.git
>>>>
>>>
>>> Sounds interesting! However, I'm out of office till end of March, and
>>> won't be able to look closely at this. But hopefully others will try it.
>>>
>>
>> Hi,
>> Didn't took the time  to read the code, I'll try to do so soon.
>> Could you tell us more about what you did and how it works ?
>> Is it similar to yaffs checkpoints ? When are the log written ?
> Not sure with yaffs checkpoints.

Yaffs works by writting it's internal memory representation on the
nand while unmounting, so it seems to be different.

> But commit writes only valid log entries.
> Log is written when an eba mapping is changed or when ec of peb is changed.

How this affect write performances ?

>> What will happen if you try to mount something that used UBIL with a
>> kernel without UBIL support ?
> It won't work.

Could it work by using a separate UBI volume with the right flag ? Are
the log per-volume ?

-- 
Corentin Chary
http://xf.iksaif.net