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/pktgen_bench_xmit_mode_queue_xmit.sh -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 4.3.2.1/32 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 4.3.2.1/32 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);