ubuntu_kernel_selftests:net:udpgso_bench.sh failed with ./udpgso_bench_tx: (sendmsg:/connect:/write:) Connection refused

[Po-Hsu Lin]

Issue found on K-azure with instance Standard_B1ms only, not a regression, just need a proper report for this.

In this case, there are 7 failures with various reason:
 * for ipv4
 # udp
 # ./udpgso_bench_tx: write: Connection refused
 # udp gso zerocopy audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso timestamp audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso zerocopy timestamp audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 * for ipv6
 # tcp
 # ./udpgso_bench_tx: connect: Connection refused
 # tcp zerocopy
 # ./udpgso_bench_tx: connect: Connection refused
 # udp
 # ./udpgso_bench_tx: write: Connection refused

 Running 'make run_tests -C net TEST_PROGS=udpgso_bench.sh TEST_GEN_PROGS='' TEST_CUSTOM_PROGS='''
 make: Entering directory '/home/azure/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/net'
 make --no-builtin-rules ARCH=x86 -C ../../../.. headers_install
 make[1]: Entering directory '/home/azure/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
   INSTALL ./usr/include
 make[1]: Leaving directory '/home/azure/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
 TAP version 13
 1..1
 # selftests: net: udpgso_bench.sh
 # ipv4
 # tcp
 # tcp tx: 4357 MB/s 73904 calls/s 73904 msg/s
 # tcp rx: 4358 MB/s 73926 calls/s
 # tcp tx: 4439 MB/s 75304 calls/s 75304 msg/s
 # tcp rx: 4443 MB/s 75368 calls/s
 # tcp tx: 4436 MB/s 75247 calls/s 75247 msg/s
 # tcp zerocopy
 # tcp tx: 3572 MB/s 60596 calls/s 60596 msg/s
 # tcp rx: 3573 MB/s 60615 calls/s
 # tcp tx: 3593 MB/s 60948 calls/s 60948 msg/s
 # tcp rx: 3596 MB/s 61005 calls/s
 # tcp tx: 3615 MB/s 61320 calls/s 61320 msg/s
 # udp
 # ./udpgso_bench_tx: write: Connection refused
 # udp gso
 # udp tx: 1793 MB/s 30421 calls/s 30421 msg/s
 # udp rx: 630 MB/s 449215 calls/s
 # udp tx: 1790 MB/s 30373 calls/s 30373 msg/s
 # udp rx: 632 MB/s 450758 calls/s
 # udp tx: 1794 MB/s 30443 calls/s 30443 msg/s
 # udp gso zerocopy
 # udp tx: 1458 MB/s 24741 calls/s 24741 msg/s
 # udp rx: 658 MB/s 468882 calls/s
 # udp tx: 1465 MB/s 24853 calls/s 24853 msg/s
 # udp rx: 655 MB/s 466606 calls/s
 # udp tx: 1466 MB/s 24870 calls/s 24870 msg/s
 # udp gso timestamp
 # udp rx: 648 MB/s 461830 calls/s
 # udp tx: 1555 MB/s 26377 calls/s 26377 msg/s
 # udp tx: 1586 MB/s 26911 calls/s 26911 msg/s
 # udp rx: 657 MB/s 468019 calls/s
 # udp tx: 1580 MB/s 26813 calls/s 26813 msg/s
 # udp gso zerocopy audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso timestamp audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso zerocopy timestamp audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # ipv6
 # tcp
 # ./udpgso_bench_tx: connect: Connection refused
 # tcp zerocopy
 # ./udpgso_bench_tx: connect: Connection refused
 # udp
 # ./udpgso_bench_tx: write: Connection refused
 # udp gso
 # udp tx: 1794 MB/s 30440 calls/s 30440 msg/s
 # udp rx: 617 MB/s 450283 calls/s
 # udp tx: 1828 MB/s 31018 calls/s 31018 msg/s
 # udp rx: 617 MB/s 450566 calls/s
 # udp tx: 1814 MB/s 30780 calls/s 30780 msg/s
 # udp gso zerocopy
 # udp tx: 1524 MB/s 25855 calls/s 25855 msg/s
 # udp rx: 627 MB/s 457879 calls/s
 # udp tx: 1542 MB/s 26166 calls/s 26166 msg/s
 # udp rx: 619 MB/s 451452 calls/s
 # udp tx: 1512 MB/s 25656 calls/s 25656 msg/s
 # udp gso timestamp
 # udp tx: 1613 MB/s 27359 calls/s 27359 msg/s
 # udp rx: 629 MB/s 458802 calls/s
 # udp tx: 1604 MB/s 27216 calls/s 27216 msg/s
 # udp rx: 634 MB/s 462953 calls/s
 # udp tx: 1581 MB/s 26817 calls/s 26817 msg/s
 # udp gso zerocopy audit
 # udp tx: 1510 MB/s 25621 calls/s 25621 msg/s
 # udp rx: 631 MB/s 460760 calls/s
 # udp tx: 1507 MB/s 25576 calls/s 25576 msg/s
 # udp rx: 629 MB/s 459105 calls/s
 # udp tx: 1534 MB/s 26034 calls/s 26034 msg/s
 # Summary over 3.000 seconds...
 # sum udp tx: 1554 MB/s 77231 calls (25743/s) 77231 msgs (25743/s)
 # Zerocopy acks: 77231
 # udp gso timestamp audit
 # udp tx: 1602 MB/s 27171 calls/s 27171 msg/s
 # udp rx: 636 MB/s 464179 calls/s
 # udp tx: 1607 MB/s 27262 calls/s 27262 msg/s
 # udp rx: 627 MB/s 457837 calls/s
 # udp tx: 1610 MB/s 27308 calls/s 27308 msg/s
 # Summary over 3.000 seconds...
 # sum udp tx: 1645 MB/s 81741 calls (27247/s) 81741 msgs (27247/s)
 # Tx Timestamps: 81741 received 0 errors
 # udp gso zerocopy timestamp audit
 # udp rx: 583 MB/s 425196 calls/s
 # udp tx: 1394 MB/s 23655 calls/s 23655 msg/s
 # udp tx: 1412 MB/s 23954 calls/s 23954 msg/s
 # udp rx: 580 MB/s 423325 calls/s
 # udp tx: 1429 MB/s 24245 calls/s 24245 msg/s
 # Summary over 3.000 seconds...
 # sum udp tx: 1446 MB/s 71854 calls (23951/s) 71854 msgs (23951/s)
 # Tx Timestamps: 71854 received 0 errors
 # Zerocopy acks: 71854
 # udpgso_bench.sh: PASS=11 SKIP=0 FAIL=7
 # udpgso_bench.sh: [0;31mFAIL[0m
 not ok 1 selftests: net: udpgso_bench.sh # exit=1

And there are 8 failures with another rerun on this same instance with the very same kernel:
* ipv4
 # tcp zerocopy
 # ./udpgso_bench_tx: connect: Connection refused
 # udp gso
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso timestamp
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso zerocopy audit
 # ./udpgso_bench_tx: sendmsg: Connection refused
* ipv6
 # tcp zerocopy
 # ./udpgso_bench_tx: connect: Connection refused
 # udp gso
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso timestamp
 # ./udpgso_bench_tx: sendmsg: Connection refused
 # udp gso zerocopy timestamp audit
 # ./udpgso_bench_tx: sendmsg: Connection refused

This test looks a bit flaky on this instance.