Chris wrote:
> Is there any "low hanging fruit" to be had as far as compromising on 
> certain file system performance aspects, but gaining a much more 
> aggressive memory footprint?

If you can accept the higher wastage you could move to larger virtual 
blocks: you could do this without touching the guts of the filesystem by 
creating a funky NAND driver which exposed a larger page size (say 8k or 
16k, or perhaps even as large as a single eraseblock) to YAFFS.

As every page of every file requires a Tnode entry, you've then at a 
stroke cut the number of entries required by a factor of four or eight. 
You've perhaps also shrunk the size of a single Tnode, and hence a few 
more bytes off every Tnode group of every file, if your NAND array had 
2^16 or more physical pages. (This wouldn't help if your filesystem 
comprised mainly small files, as I think the per-object overhead would 
dominate?)

Such a driver might conceivably be written as an intervening layer - 
that is to say, pretending to YAFFS to be an MTD device and itself 
talking to the real MTD device - which would I think be a good candidate 
to be contributed.


Ross

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