Subject: Re: [PATCH bpf-next 0/5] Bulk optimization for XDP cpumap redirect

From: Jesper Dangaard Brouer <[email-masked]>
Date: Thu, 11 Apr 2019 15:18:43 +0200

On Wed, 10 Apr 2019 16:36:40 -0700
Song Liu <[email-masked]> wrote:

> On Wed, Apr 10, 2019 at 6:00 AM Jesper Dangaard Brouer
> <[email-masked]> wrote:
> >
> > This patchset utilize a number of different kernel bulk APIs for optimizing
> > the performance for the XDP cpumap redirect feature.  
> 
> Could you please share some numbers about the optimization?

I've documented ALL the details here:
 https://github.com/xdp-project/xdp-project/blob/master/areas/cpumap/cpumap02-optimizations.org

I seem to have found that the SKB-list approach is not a performance
advantage, which is very surprising.  BUT it might still be due to
invalid benchmarking, as I found that F27 behind my back is auto-loading
iptables-filter modules, which change performance.  Thus, I have to
redo a lot of the tests...

I'm considering removing the SKB-list patch from the patchset, as all
other patches show a performance increase/improvement.  Then we can
merge that, and then I can focus on SKB-list approach in another
patchset.  BUT as I said above, I might have wrong/invalid
measurements... I have to retest before I concluded anything...

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer