Re: [PATCH] z3fold: use per-cpu unbuddied lists

[Andrew Morton]

On Wed, 2 Aug 2017 12:25:05 +0200 Vitaly Wool <vitalywool@xxxxxxxxx> wrote:

> z3fold is operating on unbuddied lists in a simple manner: in fact,
> it only takes the first entry off the list on a hot path. So if the
> z3fold pool is big enough and balanced well enough, considering
> only the lists local to the current CPU won't be an issue in any
> way, while random I/O performance will go up.

Has the performance benefit been measured?  It's a large patch.

> This patch also introduces two worker threads which: one for async
> in-page object layout optimization and one for releasing freed
> pages.

Why?  What are the runtime effects of this change?  Does this turn
currently-synchronous operations into now-async operations?  If so,
what are the implications of this if, say, the workqueue doesn't get
serviced for a while?

etc.  Sorry, but I'm not seeing anywhere near enough information and
testing results to justify merging such a large and intrusive patch.