All ubuntu_kernel_selftests/net:so_incoming_cpu tests fail

[Andrei Gherzan]

This was seen while testing the lunar:linux-aws 6.2.0-1005.5 release. All tests fail with:

Expected 2 (2) <= self->nproc (1)

Full logs from http://10.246.75.167/2023.05.15/lunar/linux-aws/6.2.0-1005.5/sru-aws-aws-a1.medium-ubuntu_kernel_selftests-log.html#net:so_incoming_cpu-start:

Running 'make run_tests -C net TEST_PROGS=so_incoming_cpu TEST_GEN_PROGS='' TEST_CUSTOM_PROGS='''
make: Entering directory '/home/ubuntu/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/net'
TAP version 13
1..1
# selftests: net: so_incoming_cpu
# TAP version 13
# 1..12
# # Starting 12 tests from 5 test cases.
# # RUN so_incoming_cpu.before_reuseport.test1 ...
# # so_incoming_cpu.c:62:test1:Expected 2 (2) <= self->nproc (1)
# # test1: Test terminated by assertion
# # FAIL so_incoming_cpu.before_reuseport.test1
# not ok 1 so_incoming_cpu.before_reuseport.test1
# # RUN so_incoming_cpu.before_reuseport.test2 ...
# # so_incoming_cpu.c:62:test2:Expected 2 (2) <= self->nproc (1)
# # test2: Test terminated by assertion
# # FAIL so_incoming_cpu.before_reuseport.test2
# not ok 2 so_incoming_cpu.before_reuseport.test2
# # RUN so_incoming_cpu.before_reuseport.test3 ...
# # so_incoming_cpu.c:62:test3:Expected 2 (2) <= self->nproc (1)
# # test3: Test terminated by assertion
# # FAIL so_incoming_cpu.before_reuseport.test3
# not ok 3 so_incoming_cpu.before_reuseport.test3
# # RUN so_incoming_cpu.before_listen.test1 ...
# # so_incoming_cpu.c:62:test1:Expected 2 (2) <= self->nproc (1)
# # test1: Test terminated by assertion
# # FAIL so_incoming_cpu.before_listen.test1
# not ok 4 so_incoming_cpu.before_listen.test1
# # RUN so_incoming_cpu.before_listen.test2 ...
# # so_incoming_cpu.c:62:test2:Expected 2 (2) <= self->nproc (1)
# # test2: Test terminated by assertion
# # FAIL so_incoming_cpu.before_listen.test2
# not ok 5 so_incoming_cpu.before_listen.test2
# # RUN so_incoming_cpu.before_listen.test3 ...
# # so_incoming_cpu.c:62:test3:Expected 2 (2) <= self->nproc (1)
# # test3: Test terminated by assertion
# # FAIL so_incoming_cpu.before_listen.test3
# not ok 6 so_incoming_cpu.before_listen.test3
# # RUN so_incoming_cpu.after_listen.test1 ...
# # so_incoming_cpu.c:62:test1:Expected 2 (2) <= self->nproc (1)
# # test1: Test terminated by assertion
# # FAIL so_incoming_cpu.after_listen.test1
# not ok 7 so_incoming_cpu.after_listen.test1
# # RUN so_incoming_cpu.after_listen.test2 ...
# # so_incoming_cpu.c:62:test2:Expected 2 (2) <= self->nproc (1)
# # test2: Test terminated by assertion
# # FAIL so_incoming_cpu.after_listen.test2
# not ok 8 so_incoming_cpu.after_listen.test2
# # RUN so_incoming_cpu.after_listen.test3 ...
# # so_incoming_cpu.c:62:test3:Expected 2 (2) <= self->nproc (1)
# # test3: Test terminated by assertion
# # FAIL so_incoming_cpu.after_listen.test3
# not ok 9 so_incoming_cpu.after_listen.test3
# # RUN so_incoming_cpu.after_all_listen.test1 ...
# # so_incoming_cpu.c:62:test1:Expected 2 (2) <= self->nproc (1)
# # test1: Test terminated by assertion
# # FAIL so_incoming_cpu.after_all_listen.test1
# not ok 10 so_incoming_cpu.after_all_listen.test1
# # RUN so_incoming_cpu.after_all_listen.test2 ...
# # so_incoming_cpu.c:62:test2:Expected 2 (2) <= self->nproc (1)
# # test2: Test terminated by assertion
# # FAIL so_incoming_cpu.after_all_listen.test2
# not ok 11 so_incoming_cpu.after_all_listen.test2
# # RUN so_incoming_cpu.after_all_listen.test3 ...
# # so_incoming_cpu.c:62:test3:Expected 2 (2) <= self->nproc (1)
# # test3: Test terminated by assertion
# # FAIL so_incoming_cpu.after_all_listen.test3
# not ok 12 so_incoming_cpu.after_all_listen.test3
# # FAILED: 0 / 12 tests passed.
# # Totals: pass:0 fail:12 xfail:0 xpass:0 skip:0 error:0
not ok 1 selftests: net: so_incoming_cpu # exit=1

It is not considered a regression as this is the first time we have run these tests for lunar:linux-aws on a non-development release, while the past development releases also have this bug. See, for example, lunar:linux-aws 6.2.0-1002.2 in d2023.03.07 (http://10.246.75.167/d2023.03.07/lunar/linux-aws/6.2.0-1002.2/sru-aws-aws-a1.medium-ubuntu_kernel_selftests-log.html#net:so_incoming_cpu-start).

As an additional note, this doesn't affect all instance types. For example, it passed on c3.xlarge while it failed on a1.medium.

[Po-Hsu Lin (cypressyew)]

This issue can be found on Lunar Azure 6.2 on instance Standard_B1ms only.