Revert "net: sctp: Fix a_rwnd/rwnd management to reflect real state of the receiver's buffer"
This reverts commit ef2820a735 ("net: sctp: Fix a_rwnd/rwnd management
to reflect real state of the receiver's buffer") as it introduced a
serious performance regression on SCTP over IPv4 and IPv6, though a not
as dramatic on the latter. Measurements are on 10Gbit/s with ixgbe NICs.
Current state:
[root@Lab200slot2 ~]# iperf3 --sctp -4 -c 192.168.241.3 -V -l 1452 -t 60
iperf version 3.0.1 (10 January 2014)
Linux Lab200slot2 3.14.0 #1 SMP Thu Apr 3 23:18:29 EDT 2014 x86_64
Time: Fri, 11 Apr 2014 17:56:21 GMT
Connecting to host 192.168.241.3, port 5201
Cookie: Lab200slot2.1397238981.812898.548918
[ 4] local 192.168.241.2 port 38616 connected to 192.168.241.3 port 5201
Starting Test: protocol: SCTP, 1 streams, 1452 byte blocks, omitting 0 seconds, 60 second test
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.09 sec 20.8 MBytes 161 Mbits/sec
[ 4] 1.09-2.13 sec 10.8 MBytes 86.8 Mbits/sec
[ 4] 2.13-3.15 sec 3.57 MBytes 29.5 Mbits/sec
[ 4] 3.15-4.16 sec 4.33 MBytes 35.7 Mbits/sec
[ 4] 4.16-6.21 sec 10.4 MBytes 42.7 Mbits/sec
[ 4] 6.21-6.21 sec 0.00 Bytes 0.00 bits/sec
[ 4] 6.21-7.35 sec 34.6 MBytes 253 Mbits/sec
[ 4] 7.35-11.45 sec 22.0 MBytes 45.0 Mbits/sec
[ 4] 11.45-11.45 sec 0.00 Bytes 0.00 bits/sec
[ 4] 11.45-11.45 sec 0.00 Bytes 0.00 bits/sec
[ 4] 11.45-11.45 sec 0.00 Bytes 0.00 bits/sec
[ 4] 11.45-12.51 sec 16.0 MBytes 126 Mbits/sec
[ 4] 12.51-13.59 sec 20.3 MBytes 158 Mbits/sec
[ 4] 13.59-14.65 sec 13.4 MBytes 107 Mbits/sec
[ 4] 14.65-16.79 sec 33.3 MBytes 130 Mbits/sec
[ 4] 16.79-16.79 sec 0.00 Bytes 0.00 bits/sec
[ 4] 16.79-17.82 sec 5.94 MBytes 48.7 Mbits/sec
(etc)
[root@Lab200slot2 ~]# iperf3 --sctp -6 -c 2001:db8:0:f101::1 -V -l 1400 -t 60
iperf version 3.0.1 (10 January 2014)
Linux Lab200slot2 3.14.0 #1 SMP Thu Apr 3 23:18:29 EDT 2014 x86_64
Time: Fri, 11 Apr 2014 19:08:41 GMT
Connecting to host 2001:db8:0:f101::1, port 5201
Cookie: Lab200slot2.1397243321.714295.2b3f7c
[ 4] local 2001:db8:0:f101::2 port 55804 connected to 2001:db8:0:f101::1 port 5201
Starting Test: protocol: SCTP, 1 streams, 1400 byte blocks, omitting 0 seconds, 60 second test
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 169 MBytes 1.42 Gbits/sec
[ 4] 1.00-2.00 sec 201 MBytes 1.69 Gbits/sec
[ 4] 2.00-3.00 sec 188 MBytes 1.58 Gbits/sec
[ 4] 3.00-4.00 sec 174 MBytes 1.46 Gbits/sec
[ 4] 4.00-5.00 sec 165 MBytes 1.39 Gbits/sec
[ 4] 5.00-6.00 sec 199 MBytes 1.67 Gbits/sec
[ 4] 6.00-7.00 sec 163 MBytes 1.36 Gbits/sec
[ 4] 7.00-8.00 sec 174 MBytes 1.46 Gbits/sec
[ 4] 8.00-9.00 sec 193 MBytes 1.62 Gbits/sec
[ 4] 9.00-10.00 sec 196 MBytes 1.65 Gbits/sec
[ 4] 10.00-11.00 sec 157 MBytes 1.31 Gbits/sec
[ 4] 11.00-12.00 sec 175 MBytes 1.47 Gbits/sec
[ 4] 12.00-13.00 sec 192 MBytes 1.61 Gbits/sec
[ 4] 13.00-14.00 sec 199 MBytes 1.67 Gbits/sec
(etc)
After patch:
[root@Lab200slot2 ~]# iperf3 --sctp -4 -c 192.168.240.3 -V -l 1452 -t 60
iperf version 3.0.1 (10 January 2014)
Linux Lab200slot2 3.14.0+ #1 SMP Mon Apr 14 12:06:40 EDT 2014 x86_64
Time: Mon, 14 Apr 2014 16:40:48 GMT
Connecting to host 192.168.240.3, port 5201
Cookie: Lab200slot2.1397493648.413274.65e131
[ 4] local 192.168.240.2 port 50548 connected to 192.168.240.3 port 5201
Starting Test: protocol: SCTP, 1 streams, 1452 byte blocks, omitting 0 seconds, 60 second test
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 240 MBytes 2.02 Gbits/sec
[ 4] 1.00-2.00 sec 239 MBytes 2.01 Gbits/sec
[ 4] 2.00-3.00 sec 240 MBytes 2.01 Gbits/sec
[ 4] 3.00-4.00 sec 239 MBytes 2.00 Gbits/sec
[ 4] 4.00-5.00 sec 245 MBytes 2.05 Gbits/sec
[ 4] 5.00-6.00 sec 240 MBytes 2.01 Gbits/sec
[ 4] 6.00-7.00 sec 240 MBytes 2.02 Gbits/sec
[ 4] 7.00-8.00 sec 239 MBytes 2.01 Gbits/sec
With the reverted patch applied, the SCTP/IPv4 performance is back
to normal on latest upstream for IPv4 and IPv6 and has same throughput
as 3.4.2 test kernel, steady and interval reports are smooth again.
Fixes: ef2820a735 ("net: sctp: Fix a_rwnd/rwnd management to reflect real state of the receiver's buffer")
Reported-by: Peter Butler <pbutler@sonusnet.com>
Reported-by: Dongsheng Song <dongsheng.song@gmail.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Peter Butler <pbutler@sonusnet.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nsn.com>
Cc: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
362d52040c