[U-Boot-Users] Very slow JFFS2 scan time and directory listing

[Stuart Wood]

On Thu, May 29, 2008 at 6:39 AM, Mark Craske <mcraske at mvista.com> wrote:
> In Message-ID:
>>       <c13b1cfc0805281223k314393a8w876ea75e1377073f at mail.gmail.com>
> you wrote:
>
>> It's taking an extremely long time to do a directory listing using the
>> 'ls' command with JFFS2.
>> Its taking nearly a minute to scan the file system and then about 1
>> second to print each line.
>>
>> What is could be the cause of this, and is there any way to speed this
>> up currently?
>
> I too am suffering from this very slow JFFS2 problem.
> It is especially bad for NAND flash.

I'm also using NAND flash, and at this time the performance off JFFS2
will not allow us to use it even though we'd like too.

> I modified the fs/jffs2/Makefile to use fs/jffs2/jffs2_nand_1pass.c
> instead of jffs2_1pass.c, but that would not build.
>
> I eventually fixed that by quite large changes, but it still ran
> very slowly despite reading larger chunks of NAND.

I've not yet looked at the code so you know more than I do, but we
were speculating
that the JFFS layer was not building an inode table in RAM, so that
each time it finds
a file it goes back to the begining of the fs and starts searching for
the next without
remembering what it has already seen.

Does this make sense? Would caching the inodes in RAM help?

--
Stuart Wood

Lab X Technologies, LLC
176 Anderson Ave.
Suite 302
Rochester, NY 14607
Phone: (585) 271-7790 x207
Fax: (585) 473.4707



-- 
Stuart Wood

Lab X Technologies, LLC
176 Anderson Ave.
Suite 302
Rochester, NY 14607
Phone: (585) 271-7790 x207
Fax: (585) 473.4707