Re: [RFC PATCH v2] bridge: make it possible for packets to traverse the bridge without hitting netfilter

On 02/26/15 17:34, David Miller wrote:

From: Imre Palik <redacted>
Date: Thu, 26 Feb 2015 11:19:25 +0100

quoted

If you are looking for peculiarities in my setup then here they are:
I am on 4k pages, and perf is not working :-(
(I am trying to fix those too, but that is far from being a low hanging fruit.)
So my guess would be that the packet pipeline doesn't fit in the cache/tlb

Pure specualtion until you can actually use perf to measure these
things.

And I don't want to apply patches which were designed based upon
pure speculation.

I did performance measurements in the following way:

Removed those pieces of the packet pipeline that I don't necessarily need one-by-one.  Then measured their effect on small packet performance.

This was the only part that produced considerable effect.

The pure speculation was about why the effect is more than 15% increase in packet throughput, although the code path avoided contains way less code than 15% of the packet pipeline.  It seems, Felix Fietkau profiled similar changes, and found my guess well founded.

Now could anybody explain me what else is wrong with my patch?  I run out of ideas what to improve.

Thanks

Imre