Re: [PATCH 00/13] lib/generic-radix-tree: genradix bug fix and optimisations.

[Kent Overstreet]

On Tue, Aug 25, 2020 at 04:00:35PM +0000, David Laight wrote:
> From: 'Marcelo Ricardo Leitner'
> > Sent: 25 August 2020 16:41
> > 
> > On Tue, Aug 25, 2020 at 02:52:34PM +0000, David Laight wrote:
> > > The genradix code is used by SCTP for accessing per-stream data.
> > > This means there are quite a lot of lookups but the code wasn't
> > > really optimised at all.
> > 
> > My test box is down for the moment and will bring it on later today or
> > tomorrow, so I can't test it yet. What should we expect as performance
> > gains here?
> 
> Not sure, probably not much, but it ought to show up :-)
> There'll be bigger gains on a cpu that has software ilog2().
> 
> I've only checked SCTP still works.
> I've requested 32k streams on a listener - to force a level-2 tree.
> I've also done at least one check with a massive pad in the sctp
> stream structure.

Have you benchmarked at all? Or were you looking at the generated assembly?