Release of UBIL: ubi with log

 

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:


We have tested ubil for samsung nand and onenand. The test results can
be found in the following git tree:


We are working on utilities and design document of UBIL. I will share
those as soon as possible.

If someone wants to try, please follow the instructions:
make menuconfig
         select ubi as module
         select ubil feature.
compile ubi module.

1) First mount of ubil is little different than ubi.

insmod ubi mtd=1,ubinize.
(Second parameter "ubinize" is introduced to avoid accidental loss of data.)
insmod ubifs
mount ubifs

2)For next mounts:
insmod ubi mtd=1
insmod ubifs
mount ubifs

Though UBIL is functionally complete,there is a lot of scope for
optimizations. All the help is very much appreciated.


Thanks and Regards,
Brijesh

 

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Add checkpointing or logging to UBIFS

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Summary Add checkpointing or logging to UBIFS Proposer Tim Bird

Contents[]

if (window.showTocToggle) { var tocShowText = "show"; var tocHideText = "hide"; showTocToggle(); } Description

Currently, the UBI file system takes a long time to be ready for use, due to a badblock scan that takes place during initialization of UBI (the UBI attach operation). The scan takes a time that is linearly proportional to the size of flash. As flash sizes grow, the delay caused by this scan becomes a problem.

It would be beneficial to eliminate the scan, or make it more scalable, using some kind of checkpointing or logging.

Related work

• UBIFS
• UBI2
  • see portions of http://www.mjmwired.net/kernel/Documentation/filesystems/ubifs.txt
• Mount times
  • http://elinux.org/images/f/f8/CELFJamboree30-UBIFS_update.pdf

• This proposal was suggested last year, but the project was not done
  • See

UBI logging feature submitted by Samsung

A developer with Samsung (in India) proposed UBIL - UBI logging - to solve this problem, in April 2010.

• Initial announcement:
  • performance improvement:
  • 98bcb6b4329ba7e8c770:/nand_mount_time.pdf
  • patches in April, 2010:

I seem to recall someone at the kernel summit (maybe Thomas) telling me that these patches improved the speed, but still had scalability proportional to the flash size.

Scope

A rough estimate would be 3 months of development and test work, followed by some work to mainline the changes upstream.

Contractor Candidates

• Thomas Gleixner
• Artem Bityutskiy
• Free Electrons

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