> Also, I'm puzzled why it would the space increase would proportional
> to the amount of data and be more than 300 bytes. There's no reason it
> wouldn't be a small fixed amount. The ideal is you set aside one bit
> -- if the bit is set the rest is compressed and has to save at least
> one bit. If the bit is not set then the rest is uncompressed. Maximum
> bloat is 1-bit. In real systems it's more likely to be a byte or a
> word.
I'm working on cleaning the patch...
I added a field in PageHeader which contains :- 0 to indicate a non-compressed page- length of compressed data if
compressed
If compression gains nothing (ie gains less than 4K), the page is stored
raw.
It seems that only pages having a PageHeader are handled by md.c, so it
should work (am I mistaken ?)