jffs2 fragmentation

[David Woodhouse]

On Sat, 2003-10-18 at 09:20 -0500, J B wrote:
> Normally, a rm/cp pair takes about 2 minutes on my system.  After about 10 
> iterations, the copies begin to take longer, about 3-4 minutes.   After 
> about 10 iterations they take upwards of 1/2 an hour.

I suspect you've triggered the worst case of a performance bug which
I've known about for a while.

We should write new data out to one empty block, while writing out
garbage-collected data out to another. We don't do that at the moment;
we interleave old and new data and then you erase your new file, leaving
us with a very suboptimal mix of valid and obsolete nodes in each
eraseblock we've been writing to.

I'm still a bit surprised it takes half an hour though. 

-- 
dwmw2