; Summary: Add checkpointing or logging to UBIFS ; Proposer: Tim Bird
== 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 ** http://en.wikipedia.org/wiki/UBIFS ** http://lwn.net/Articles/276025/ * UBI2 ** see portions of http://www.mjmwired.net/kernel/Documentation/filesystems/ubifs.txt * Mount times ** http://osl.sed.hu/wiki/ubifs/index.php/Mount_results ** http://elinux.org/images/f/f8/CELFJamboree30-UBIFS_update.pdf * This proposal was suggested last year, but the project was not done ** See http://elinux.org/CELF_Project_Proposal/UBIFS_mount_time_speedups === 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: http://lists.infradead.org/pipermail/linux-mtd/2010-February/029256.html ** performance improvement: http://git.infradead.org/users/brijesh/ubil_results/blob/da4f975b5a2fc5cb2f9398bcb6b4329ba7e8c770:/nand_mount_time.pdf ** patches in April, 2010: http://lists.infradead.org/pipermail/linux-mtd/2010-April/029573.html 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 == Comments == [[Category:Project proposals 2011]] ============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Network Entertainment ============================= _______________________________________________ Celinux-dev mailing list [email protected] http://tree.celinuxforum.org/mailman/listinfo/celinux-dev
