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From: Lukas Wunner <>
To: Pablo Neira Ayuso <>
Cc: Jozsef Kadlecsik <>,
	Florian Westphal <>,,,, Martin Mares <>,
	Daniel Borkmann <>
Subject: Re: [PATCH nf-next,RFC 0/5] Netfilter egress hook
Date: Sat, 23 Nov 2019 14:11:08 +0100
Message-ID: <> (raw)
In-Reply-To: <20191107225149.5t4sg35b5gwuwawa@salvia>

On Thu, Nov 07, 2019 at 11:51:49PM +0100, Pablo Neira Ayuso wrote:
> On Thu, Oct 31, 2019 at 02:41:00PM +0100, Lukas Wunner wrote:
> > Introduce a netfilter egress hook to complement the existing ingress hook.
> Would you provide some numbers on the performance impact for this new
> hook?

For some reason the numbers are slightly better with this series.

Could be caused by the __always_inline in patch 4, I'd have to compare
the disassembly to confirm this hunch.

* Without this patch:
  Result: OK: 34205373(c34202809+d2564) usec, 100000000 (60byte,0frags)
  2923517pps 1403Mb/sec (1403288160bps) errors: 0

* With this patch:
  Result: OK: 34106013(c34103172+d2841) usec, 100000000 (60byte,0frags)
  2932034pps 1407Mb/sec (1407376320bps) errors: 0

* Without this patch + tc egress:
  Result: OK: 37848652(c37846140+d2511) usec, 100000000 (60byte,0frags)
  2642102pps 1268Mb/sec (1268208960bps) errors: 0

* With this patch + tc egress:
  Result: OK: 37784817(c37782026+d2791) usec, 100000000 (60byte,0frags)
  2646565pps 1270Mb/sec (1270351200bps) errors: 0

* With this patch + nft egress:
  Result: OK: 43911936(c43908932+d3003) usec, 100000000 (60byte,0frags)
  2277285pps 1093Mb/sec (1093096800bps) errors: 0

Tested on a bare-metal Core i7-3615QM, each measurement was performed
twice to verify that the numbers are stable.

Commands to perform a measurement:
modprobe pktgen
echo "add_device lo@3" > /proc/net/pktgen/kpktgend_3
samples/pktgen/ -i 'lo@3' -n 100000000

Commands for testing tc egress:
tc qdisc add dev lo clsact
tc filter add dev lo egress protocol ip prio 1 u32 match ip dst

Commands for testing nft egress:
nft add table netdev t
nft add chain netdev t co \{ type filter hook egress device lo priority 0 \; \}
nft add rule netdev t co ip daddr drop

All testing was performed on the loopback interface to avoid distorting
measurements by the packet handling in the low-level Ethernet driver.
This required the following small patch:

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index bb99152..020c825 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2003,8 +2003,8 @@ static int pktgen_setup_dev(const struct pktgen_net *pn,
 		return -ENODEV;
-	if (odev->type != ARPHRD_ETHER) {
-		pr_err("not an ethernet device: \"%s\"\n", ifname);
+	if (odev->type != ARPHRD_ETHER && odev->type != ARPHRD_LOOPBACK) {
+		pr_err("not an ethernet or loopback device: \"%s\"\n", ifname);
 		err = -EINVAL;
 	} else if (!netif_running(odev)) {
 		pr_err("device is down: \"%s\"\n", ifname);

      reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-31 13:41 Lukas Wunner
2019-10-31 13:41 ` [PATCH nf-next,RFC 1/5] netfilter: Clean up unnecessary #ifdef Lukas Wunner
2019-10-31 13:41 ` [PATCH nf-next,RFC 2/5] netfilter: Document ingress hook Lukas Wunner
2019-10-31 13:41 ` [PATCH nf-next,RFC 3/5] netfilter: Rename ingress hook include file Lukas Wunner
2019-10-31 13:41 ` [PATCH nf-next,RFC 4/5] netfilter: Generalize ingress hook Lukas Wunner
2019-10-31 13:41 ` [PATCH nf-next,RFC 5/5] netfilter: Introduce egress hook Lukas Wunner
2019-10-31 22:39   ` Daniel Borkmann
2019-11-23 14:23     ` Lukas Wunner
2019-11-07 22:51 ` [PATCH nf-next,RFC 0/5] Netfilter " Pablo Neira Ayuso
2019-11-23 13:11   ` Lukas Wunner [this message]

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