On Thu, 31 Aug 2017 18:23:49 +0200 Michal Kubecek <mkube...@suse.cz> wrote:
> If we go this way (which would IMHO require some benchmarks to make sure
> it doesn't harm performance too much) we can drop the explicit checks
> for zero thresholds which were added to work around the unreliability of
> fast checks of percpu counters (or at least the second one was by commit
> 30759219f562 ("net: disable fragment reassembly if high_thresh is zero").
After much considerations, together with Florian, I'm now instead
looking at reverting the use of percpu_counter for this memory
accounting use-case. The complexity and maintenance cost is not worth
it. And I'm of-cause testing the perf effect, and currently I'm _not_
seeing any perf regression on my 10G + 100G testlab (although this is
not a NUMA system, which were my original optimization case).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
