Subject: Re: [PATCH net-next] dql: dql_queued() should write first to reduce bus transactions

From: Jesper Dangaard Brouer <[email-masked]>
Date: Fri, 26 Sep 2014 10:47:32 +0200

On Thu, 25 Sep 2014 23:04:56 -0700
Eric Dumazet <[email-masked]> wrote:

[...]
> 
> It turned out the problem was caused by compiler trying to be
> smart, but involving a bad MESI transaction :
>
[...] 
> 
> I got an incredible 10 % gain [1] by making sure cpu do not attempt
> to get the cache line in Shared mode, but directly requests for
> ownership.
[...]
> 
> Signed-off-by: Eric Dumazet <[email-masked]>
> ---

I'm very impressed - thank you Eric for finding this!!!

Acked-by: Jesper Dangaard Brouer <[email-masked]>

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Sr. Network Kernel Developer at Red Hat
  Author of http://www.iptv-analyzer.org
  LinkedIn: http://www.linkedin.com/in/brouer