[U-Boot] [PATCH,V2] JFFS2: accelerate scanning.

[Detlev Zundel]

Hi Baidu,

>  Syncs up with jffs2 in the linux kernel:
>  1/ Change DEFAULT_EMPTY_SCAN_SIZE from 4KB to 256 Bytes.
>  2/ If the 1KB data is 0xFF after the cleanmarker, skip
>  and scan the next sector.
>  3/ Change the buffer size from 4KB to 128KB which is the
>  common size of erase block.

There is no "common size of erase block".  Looking into the Linux code,
it uses "max(erase block size, 128k)" for its buffer to speed up reading
from NAND and the 128k seem to be a kmalloc limit.

So maybe a "increase buffer size from 4KiB to 128KiB to reduce number of
read operations" would be more fitting.  By the way, does this change
contribute to the performance increase at all, or is the increase simply
due to DEFAULT_EMPTY_SCAN_SIZE?

Also as for the other patch, can you split the commit into the
individual changes corresponding to the list items?  In this way, one
could also easily measure which change really speeds up the operation...

Thanks!
  Detlev

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