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From: Alexei Starovoitov <ast@plumgrid•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: "David S. Miller" <davem@davemloft•net>,
	Eric Dumazet <edumazet@google•com>,
	Daniel Borkmann <daniel@iogearbox•net>,
	Thomas Graf <tgraf@suug•ch>, Jamal Hadi Salim <jhs@mojatatu•com>,
	John Fastabend <john.r.fastabend@intel•com>,
	netdev@vger•kernel.org
Subject: Re: [PATCH RFC net-next] pktgen: introduce 'rx' mode
Date: Wed, 29 Apr 2015 16:28:05 -0700	[thread overview]
Message-ID: <55416905.7070308@plumgrid.com> (raw)
In-Reply-To: <1430348211.3711.66.camel@edumazet-glaptop2.roam.corp.google.com>

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?

  reply	other threads:[~2015-04-29 23:28 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-29  2:11 [PATCH RFC net-next] netif_receive_skb performance Alexei Starovoitov
2015-04-29  2:11 ` [PATCH RFC net-next] pktgen: introduce 'rx' mode Alexei Starovoitov
2015-04-29  4:14   ` Eric Dumazet
2015-04-29 21:55     ` Alexei Starovoitov
2015-04-29 22:19       ` Eric Dumazet
2015-04-29 22:38         ` Alexei Starovoitov
2015-04-29 22:56           ` Eric Dumazet
2015-04-29 23:28             ` Alexei Starovoitov [this message]
2015-04-29 23:39               ` Eric Dumazet
2015-04-29 23:59                 ` Alexei Starovoitov
2015-04-29  5:23 ` [PATCH RFC net-next] netif_receive_skb performance Eric Dumazet
2015-04-29 22:15   ` Alexei Starovoitov
2015-04-29  9:37 ` Daniel Borkmann
2015-04-29 22:20   ` Alexei Starovoitov

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