mirror_ubuntu-kernels/tools/testing
Yonghong Song b16ac5bf73 selftests/bpf: Fix flaky send_signal test
libbpf CI has reported send_signal test is flaky although
I am not able to reproduce it in my local environment.
But I am able to reproduce with on-demand libbpf CI ([1]).

Through code analysis, the following is possible reason.
The failed subtest runs bpf program in softirq environment.
Since bpf_send_signal() only sends to a fork of "test_progs"
process. If the underlying current task is
not "test_progs", bpf_send_signal() will not be triggered
and the subtest will fail.

To reduce the chances where the underlying process is not
the intended one, this patch boosted scheduling priority to
-20 (highest allowed by setpriority() call). And I did
10 runs with on-demand libbpf CI with this patch and I
didn't observe any failures.

 [1] https://github.com/libbpf/libbpf/actions/workflows/ondemand.yml

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817190923.3186725-1-yhs@fb.com
2021-08-17 14:08:30 -07:00
..
fault-injection
ktest bootconfig/tracing/ktest: Add ktest examples of testing bootconfig 2021-06-24 15:34:33 -04:00
kunit kunit: tool: Assert the version requirement 2021-07-12 14:02:32 -06:00
nvdimm ACPI: NFIT: Fix support for variable 'SPA' structure size 2021-05-12 12:38:25 -07:00
radix-tree idr test suite: Improve reporting from idr_find_test_1 2021-04-01 07:50:42 -04:00
scatterlist tools/testing/scatterlist: Fix overflow of max segment size 2021-01-28 15:17:39 -04:00
selftests selftests/bpf: Fix flaky send_signal test 2021-08-17 14:08:30 -07:00
vsock vsock_test: add SOCK_SEQPACKET tests 2021-06-11 13:32:47 -07:00