From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: Re: [PATCH RFC net-next] netif_receive_skb performance Date: Wed, 29 Apr 2015 15:20:13 -0700 Message-ID: <5541591D.3070505@plumgrid.com> References: <1430273488-8403-1-git-send-email-ast@plumgrid.com> <5540A665.7030406@iogearbox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , Thomas Graf , Jamal Hadi Salim , John Fastabend , netdev@vger.kernel.org To: Daniel Borkmann , "David S. Miller" Return-path: Received: from mail-pd0-f175.google.com ([209.85.192.175]:34258 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751246AbbD2WUQ (ORCPT ); Wed, 29 Apr 2015 18:20:16 -0400 Received: by pdbqa5 with SMTP id qa5so40726865pdb.1 for ; Wed, 29 Apr 2015 15:20:16 -0700 (PDT) In-Reply-To: <5540A665.7030406@iogearbox.net> Sender: netdev-owner@vger.kernel.org List-ID: On 4/29/15 2:37 AM, Daniel Borkmann wrote: > > Is the below the case where the conntracker has always a miss and thus > each time needs to create new entries, iow pktgen DoS with random IPs? not really. As far as I understand it's not doing much, just being invoked as part of default code path. Not sure. This was a default number on my setup with all modules loaded. I have empty iptables/nat/ct rules. I mentioned it, since that is what most linux users will see by default from their distro. >> Few other numbers for comparison with dmac == eth0 mac: >> no qdisc, with conntrack and empty iptables - 2.2 Mpps >> 7.65% kpktgend_0 [nf_conntrack] [k] nf_conntrack_in >> 7.62% kpktgend_0 [kernel.vmlinux] [k] fib_table_lookup >> 5.44% kpktgend_0 [kernel.vmlinux] [k] __call_rcu.constprop.63 >> 3.71% kpktgend_0 [kernel.vmlinux] [k] nf_iterate >> 3.59% kpktgend_0 [ip_tables] [k] ipt_do_table >> >> no qdisc, unload conntrack, keep empty iptables - 5.4 Mpps >> 18.17% kpktgend_0 [kernel.vmlinux] [k] fib_table_lookup >> 8.31% kpktgend_0 [kernel.vmlinux] [k] ip_rcv >> 7.97% kpktgend_0 [kernel.vmlinux] [k] __netif_receive_skb_core >> 7.53% kpktgend_0 [ip_tables] [k] ipt_do_table >> >> no qdisc, unload conntrack, unload iptables - 6.5 Mpps >> 21.97% kpktgend_0 [kernel.vmlinux] [k] fib_table_lookup >> 9.64% kpktgend_0 [kernel.vmlinux] [k] __netif_receive_skb_core >> 8.44% kpktgend_0 [kernel.vmlinux] [k] ip_rcv >> 7.19% kpktgend_0 [kernel.vmlinux] [k] __skb_clone >> 6.89% kpktgend_0 [kernel.vmlinux] [k] fib_validate_source