Subject: Re: [PATCH RFC net-next] pktgen: introduce 'rx' mode

From: Alexei Starovoitov <[email-masked]>
Date: Wed, 29 Apr 2015 16:28:05 -0700

On 4/29/15 3:56 PM, Eric Dumazet wrote:
>
> So pktgen in RX mode MUST deliver skb with skb->users = 1, there is no
> way around it.

if I only knew how to do it...
The cost of continuously allocating skbs is way higher than
netif_receive_skb itself. Such benchmarking tool would measure the
speed of skb alloc/free instead of speed of netif_receive_skb.
Are you suggesting to pre-allocate 10s of millions of skbs and
then feed them in one go? The profile will be dominated by
cache misses in the first few lines of __netif_receive_skb_core()
where it accesses skb->dev,data,head. Doesn't sound too useful either.
Other thoughts?