Packet size can make a big difference to UDP throughput, so it makes sense
to measure it for a variety of different sizes. Currently we do this by
adjusting the MTU on the relevant interface before running iperf3.
However, the UDP packet size has no inherent connection to the MTU - it's
controlled by the sender, and the MTU just affects whether the packet will
make it through or be fragmented. The only reason adjusting the MTU works
is because iperf3 bases its default packet size on the (path) MTU.
We can test this more simply by using the -l option to the iperf3 client
to directly control the packet size, instead of adjusting the MTU.
As well as simplifying this lets us test different packet sizes for host to
ns traffic. We couldn't do that previously because we don't have
permission to change the MTU on the host.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
test/perf/passt_udp | 69 +++++++++++-------------------
test/perf/pasta_udp | 100 ++++++++++++++++++++++----------------------
2 files changed, 75 insertions(+), 94 deletions(-)
diff --git a/test/perf/passt_udp b/test/perf/passt_udp
index 12d8fbb..10f638f 100644
--- a/test/perf/passt_udp
+++ b/test/perf/passt_udp
@@ -39,24 +39,21 @@ info Throughput in Gbps, latency in µs, __THREADS__ threads at
__FREQ__ GHz, on
report passt udp __THREADS__ __FREQ__
-th MTU 256B 576B 1280B 1500B 9000B 65520B
+th pktlen 256B 576B 1280B 1500B 9000B 65520B
tr UDP throughput over IPv6: guest to host
iperf3s ns 100${i}2 __THREADS__
+# (datagram size) = (packet size) - 48: 40 bytes of IPv6 header, 8 of UDP header
bw -
bw -
-guest ip link set dev __IFNAME__ mtu 1280
-iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1232
bw __BW__ 0.8 1.2
-guest ip link set dev __IFNAME__ mtu 1500
-iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1452
bw __BW__ 1.0 1.5
-guest ip link set dev __IFNAME__ mtu 9000
-iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 5G
+iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 5G -l 8952
bw __BW__ 4.0 5.0
-guest ip link set dev __IFNAME__ mtu 65520
-iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 7G
+iperf3 BW guest __GW6__%__IFNAME__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 7G -l 64372
bw __BW__ 4.0 5.0
iperf3k ns
@@ -74,24 +71,19 @@ lat __LAT__ 200 150
tr UDP throughput over IPv4: guest to host
iperf3s ns 100${i}2 __THREADS__
+# (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
-guest ip link set dev __IFNAME__ mtu 256
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 500M
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 500M -l 228
bw __BW__ 0.0 0.0
-guest ip link set dev __IFNAME__ mtu 576
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 1G
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 1G -l 548
bw __BW__ 0.4 0.6
-guest ip link set dev __IFNAME__ mtu 1280
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1252
bw __BW__ 0.8 1.2
-guest ip link set dev __IFNAME__ mtu 1500
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1472
bw __BW__ 1.0 1.5
-guest ip link set dev __IFNAME__ mtu 9000
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 6G
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 6G -l 8972
bw __BW__ 4.0 5.0
-guest ip link set dev __IFNAME__ mtu 65520
-iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 7G
+iperf3 BW guest __GW__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 7G -l 65492
bw __BW__ 4.0 5.0
iperf3k ns
@@ -109,20 +101,17 @@ lat __LAT__ 200 150
tr UDP throughput over IPv6: host to guest
iperf3s guest 100${i}1 __THREADS__
+# (datagram size) = (packet size) - 48: 40 bytes of IPv6 header, 8 of UDP header
bw -
bw -
-ns ip link set dev lo mtu 1280
-iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1232
bw __BW__ 0.8 1.2
-ns ip link set dev lo mtu 1500
-iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1452
bw __BW__ 1.0 1.5
-ns ip link set dev lo mtu 9000
-iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 8952
bw __BW__ 3.0 4.0
-ns ip link set dev lo mtu 65520
-iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns ::1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 64372
bw __BW__ 3.0 4.0
iperf3k guest
@@ -137,30 +126,23 @@ guestb udp_rr --nolog -P 10001 -C 10011 -6
sleep 1
nsout LAT udp_rr --nolog -P 10001 -C 10011 -6 -c -H ::1 | sed -n
's/^throughput=\(.*\)/\1/p'
lat __LAT__ 200 150
-ns ip link set dev lo mtu 65535
tr UDP throughput over IPv4: host to guest
iperf3s guest 100${i}1 __THREADS__
+# (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
-ns ip link set dev lo mtu 256
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 1G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 1G -l 228
bw __BW__ 0.0 0.0
-ns ip link set dev lo mtu 576
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 1G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 1G -l 548
bw __BW__ 0.4 0.6
-ns ip link set dev lo mtu 1280
-ns ip addr add ::1 dev lo
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1252
bw __BW__ 0.8 1.2
-ns ip link set dev lo mtu 1500
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1472
bw __BW__ 1.0 1.5
-ns ip link set dev lo mtu 9000
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 8972
bw __BW__ 3.0 4.0
-ns ip link set dev lo mtu 65520
-iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}1 __THREADS__ __TIME__ __OPTS__ -b 3G -l 65492
bw __BW__ 3.0 4.0
iperf3k guest
@@ -175,6 +157,5 @@ guestb udp_rr --nolog -P 10001 -C 10011 -4
sleep 1
nsout LAT udp_rr --nolog -P 10001 -C 10011 -4 -c -H 127.0.0.1 | sed -n
's/^throughput=\(.*\)/\1/p'
lat __LAT__ 200 150
-ns ip link set dev lo mtu 65535
te
diff --git a/test/perf/pasta_udp b/test/perf/pasta_udp
index 0628bd9..5e3db1e 100644
--- a/test/perf/pasta_udp
+++ b/test/perf/pasta_udp
@@ -29,23 +29,20 @@ info Throughput in Gbps, latency in µs, one thread at __FREQ__ GHz,
__STREAMS__
report pasta lo_udp 1 __FREQ__
-th MTU 1500B 4000B 16384B 65535B
+th pktlen 1500B 4000B 16384B 65535B
tr UDP throughput over IPv6: ns to host
iperf3s host 100${i}3 __THREADS__
+# (datagram size) = (packet size) - 48: 40 bytes of IPv6 header, 8 of UDP header
-ns ip link set dev lo mtu 1500
-iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1452
bw __BW__ 1.0 1.5
-ns ip link set dev lo mtu 4000
-iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
bw __BW__ 1.2 1.8
-ns ip link set dev lo mtu 16384
-iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 10G
+iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 10G -l 16336
bw __BW__ 5.0 6.0
-ns ip link set dev lo mtu 65535
-iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW ns ::1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 15G -l 65487
bw __BW__ 7.0 9.0
iperf3k host
@@ -62,18 +59,15 @@ lat __LAT__ 200 150
tr UDP throughput over IPv4: ns to host
iperf3s host 100${i}3 __THREADS__
+# (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
-ns ip link set dev lo mtu 1500
-iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1372
bw __BW__ 1.0 1.5
-ns ip link set dev lo mtu 4000
-iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
bw __BW__ 1.2 1.8
-ns ip link set dev lo mtu 16384
-iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 10G
+iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 10G -l 16356
bw __BW__ 5.0 6.0
-ns ip link set dev lo mtu 65535
-iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW ns 127.0.0.1 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 15G -l 65507
bw __BW__ 7.0 9.0
iperf3k host
@@ -91,10 +85,13 @@ lat __LAT__ 200 150
tr UDP throughput over IPv6: host to ns
iperf3s ns 100${i}2 __THREADS__
-bw -
-bw -
-bw -
-iperf3 BW host ::1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW host ::1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1452
+bw __BW__ 1.0 1.5
+iperf3 BW host ::1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
+bw __BW__ 1.2 1.8
+iperf3 BW host ::1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 10G -l 16336
+bw __BW__ 5.0 6.0
+iperf3 BW host ::1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G -l 16336
bw __BW__ 7.0 9.0
iperf3k ns
@@ -111,10 +108,13 @@ lat __LAT__ 200 150
tr UDP throughput over IPv4: host to ns
iperf3s ns 100${i}2 __THREADS__
-bw -
-bw -
-bw -
-iperf3 BW host 127.0.0.1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW host 127.0.0.1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 1372
+bw __BW__ 1.0 1.5
+iperf3 BW host 127.0.0.1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
+bw __BW__ 1.2 1.8
+iperf3 BW host 127.0.0.1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 10G -l 16356
+bw __BW__ 5.0 6.0
+iperf3 BW host 127.0.0.1 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G -l 65507
bw __BW__ 7.0 9.0
iperf3k ns
@@ -141,22 +141,19 @@ nsout IFNAME ip -j link show | jq -rM '.[] | select(.link_type
== "ether").ifnam
info Throughput in Gbps, latency in µs, one thread at __FREQ__ GHz, __STREAMS__ streams
report pasta tap_udp 1 __FREQ__
-th MTU 1500B 4000B 16384B 65520B
+th pktlen 1500B 4000B 16384B 65520B
tr UDP throughput over IPv6: ns to host
iperf3s host 100${i}3 __THREADS__
+# (datagram size) = (packet size) - 48: 40 bytes of IPv6 header, 8 of UDP header
-ns ip link set dev __IFNAME__ mtu 1500
-iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1472
bw __BW__ 0.3 0.5
-ns ip link set dev __IFNAME__ mtu 4000
-iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
bw __BW__ 0.5 0.8
-ns ip link set dev __IFNAME__ mtu 16384
-iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 4G
+iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 4G -l 16356
bw __BW__ 3.0 4.0
-ns ip link set dev __IFNAME__ mtu 65520
-iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 6G
+iperf3 BW ns __GW6__%__IFNAME__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 6G -l 65472
bw __BW__ 6.0 7.0
iperf3k host
@@ -173,18 +170,15 @@ lat __LAT__ 200 150
tr UDP throughput over IPv4: ns to host
iperf3s host 100${i}3 __THREADS__
+# (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
-ns ip link set dev __IFNAME__ mtu 1500
-iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 2G
+iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1472
bw __BW__ 0.3 0.5
-ns ip link set dev __IFNAME__ mtu 4000
-iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G
+iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
bw __BW__ 0.5 0.8
-ns ip link set dev __IFNAME__ mtu 16384
-iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 4G
+iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 4G -l 16356
bw __BW__ 3.0 4.0
-ns ip link set dev __IFNAME__ mtu 65520
-iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 6G
+iperf3 BW ns __GW__ 100${i}3 __THREADS__ __TIME__ __OPTS__ -b 6G -l 65492
bw __BW__ 6.0 7.0
iperf3k host
@@ -203,10 +197,13 @@ iperf3s ns 100${i}2 __THREADS__
nsout IFNAME ip -j link show | jq -rM '.[] | select(.link_type ==
"ether").ifname'
nsout ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[] | select(.scope == "global" and .prefixlen
== 64).local'
-bw -
-bw -
-bw -
-iperf3 BW host __ADDR6__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW host __ADDR6__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1472
+bw __BW__ 0.3 0.5
+iperf3 BW host __ADDR6__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
+bw __BW__ 0.5 0.8
+iperf3 BW host __ADDR6__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 4G -l 16356
+bw __BW__ 3.0 4.0
+iperf3 BW host __ADDR6__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G -l 65472
bw __BW__ 7.0 9.0
iperf3k ns
@@ -225,10 +222,13 @@ tr UDP throughput over IPv4: host to ns
iperf3s ns 100${i}2 __THREADS__
nsout ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname ==
"__IFNAME__").addr_info[0].local'
-bw -
-bw -
-bw -
-iperf3 BW host __ADDR__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G
+iperf3 BW host __ADDR__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 2G -l 1472
+bw __BW__ 0.3 0.5
+iperf3 BW host __ADDR__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 3G -l 3972
+bw __BW__ 0.5 0.8
+iperf3 BW host __ADDR__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 4G -l 16356
+bw __BW__ 3.0 4.0
+iperf3 BW host __ADDR__ 100${i}2 __THREADS__ __TIME__ __OPTS__ -b 15G -l 65492
bw __BW__ 7.0 9.0
iperf3k ns
--
2.41.0