Re: [PATCH] Radix-tree pagecache for 2.5

[William Lee Irwin III]

On Tue, Jan 29, 2002 at 04:54:44PM +0100, Christoph Hellwig wrote:
> I've ported my hacked up version of Momchil Velikov's radix tree
> radix tree pagecache to 2.5.3-pre{5,6}.
> The changes over the 2.4.17 version are:
>   o use mempool to avoid OOM situation involving radix nodes.
>   o remove add_to_page_cache_locked, it was unused in the 2.4.17 patch.
>   o unify add_to_page and add_to_page_unique
> It gives nice scalability improvements on big machines and drops the
> memory usage on small ones (if you consider my 64MB Athlon small :)).

I love this patch. My only concern is about worst-case space consumption,
but it is beautiful regardless, and space consumption can be addressed
later if it is a problem in practice. The average case space consumption,
as you have noted, is quite good already, and it seems difficult to
trigger the worst case (I have tested it myself).

Cheers,
Bill