multiple MTD partitions
krstic at solarsail.hcs.harvard.edu
Mon Dec 17 01:16:37 EST 2007
On Dec 16, 2007, at 11:40 PM, John Watlington wrote:
> I'm curious how you measured this, as the underlying hardware only
> supports a max. transfer rate of around 20 MiB/s...
As Artem mentioned, UBIFS employs a write-back cache, meaning writes
aren't flushed to the underlying medium immediately; pages are instead
marked dirty in the page cache and written back when evicted.
This makes a hell of a lot of sense. In a synchronous filesystem like
JFFS2, constant and repeated writes to the same single page will keep
pummeling the underlying flash needlessly. With UBIFS, such writes
succeed instantly but only cause a write/erase cycle on the flash to
be triggered when the page gets kicked out of the page cache either
because the RAM is needed or because of the kernel thread performing
dirty page writeback on a timer.
Ivan Krstić <krstic at solarsail.hcs.harvard.edu> | http://radian.org
More information about the Devel