Re: [PATCH] z3fold: the 3-fold allocator for compressed pages

From: Vlastimil Babka
Date: Thu Apr 14 2016 - 04:49:00 EST


On 04/14/2016 10:05 AM, Vitaly Wool wrote:
This patch introduces z3fold, a special purpose allocator for storing
compressed pages. It is designed to store up to three compressed pages per
physical page. It is a ZBUD derivative which allows for higher compression
ratio keeping the simplicity and determinism of its predecessor.

So the obvious question is, why a separate allocator and not extend zbud?
I didn't study the code, nor notice a design/algorithm overview doc, but it seems z3fold keeps the idea of one compressed page at the beginning, one at the end of page frame, but it adds another one in the middle? Also how is the buddy-matching done?

Thanks,
Vlastimil