Re: Review of Thomas's >2GB ext2fs proposal

[Neal H. Walfield]

> I'm back online :-)

Welcome back.

> Neal H. Walfield wrote:
> > Yes, we remove the data from memory any time we remove a mapping but
> > we only remove mappings when Mach evicts the data.
> 
> Just a small techical correction: we remove mapping only when we are 
> remapping page to contain another block.  So when page is evicted, it 
> continues to map the same disk block until ext2fs decides that we want 
> this page to hold another block (only if page is still evicted, of
> course).

Well, I think we ought to drain the mapping cache when the page is
evicted.  This keeps memory usage lower.  Further, relative to the
cost of reading from disk, adding an entry to the hashes, etc. is
cheap.

Neal