On Thu, Jul 26, 2012 at 3:53 PM, David Miller [off-list ref] wrote:

From: Alexander Duyck <redacted>
Date: Thu, 26 Jul 2012 15:03:39 -0700

quoted

Here is the latest perf results with all of these patches in place.
As you predicted your patch essentially cut the lookup overhead in
half:

Ok good.

That patch is hard to make legitimate, I'd have to do a bit or work
before we could realize that change.

We can only combine the LOCAL and MAIN tables like that so long as
there are no overlaps in the routes covered by the two tables.  We'd
also have to be sure to report the routes properly in dumps too.

I really wish we had never segregated these two tables, it's
completely pointless and hurts performance.  But now we have to
accomodate this legacy.

Any idea why these look-ups are so expensive in the first place?  When
I dump fib_trie it doesn't look like I have much there.  I would have
thought the table would be pretty static with just 8 flows all going
to the same destination address, but it seems like I was getting hit
with cache misses for some reason.

Thanks,

Alex