[PATCH v9 38/39] kselftest/arm64: Add a GCS stress test

[Thiago Jung Bauermann]

Mark Brown <broonie at kernel.org> writes:

> Add a stress test which runs one more process than we have CPUs spinning
> through a very recursive function with frequent syscalls immediately prior
> to return and signals being injected every 100ms. The goal is to flag up
> any scheduling related issues, for example failure to ensure that barriers
> are inserted when moving a GCS using task to another CPU. The test runs for
> a configurable amount of time, defaulting to 10 seconds.
>
> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann at linaro.org>
> Signed-off-by: Mark Brown <broonie at kernel.org>
> ---
>  tools/testing/selftests/arm64/gcs/.gitignore       |   2 +
>  tools/testing/selftests/arm64/gcs/Makefile         |   6 +-
>  tools/testing/selftests/arm64/gcs/asm-offsets.h    |   0
>  .../selftests/arm64/gcs/gcs-stress-thread.S        | 311 ++++++++++++
>  tools/testing/selftests/arm64/gcs/gcs-stress.c     | 532 +++++++++++++++++++++
>  5 files changed, 850 insertions(+), 1 deletion(-)

This test fails for me, even without THP:

$ sudo ./run_kselftest.sh -t arm64:gcs-stress
TAP version 13
1..1
# timeout set to 45
# selftests: arm64: gcs-stress
# TAP version 13
# 1..9
# # 8 CPUs, 9 GCS threads
# # Will run for 10s
# # Started Thread-4030
# # Started Thread-4031
# # Started Thread-4032
# # Started Thread-4033
# # Started Thread-4034
# # Started Thread-4035
# # Started Thread-4036
# # Started Thread-4037
# # Started Thread-4038
# # Waiting for 9 children
# # Waiting for 9 children
# # Thread-4030: Failed to enable GCS
# # Thread-4031: Failed to enable GCS
# # Thread-4032: Failed to enable GCS
# # Thread-4033: Failed to enable GCS
# # Thread-4034: Failed to enable GCS
# # Thread-4035: Failed to enable GCS
# # Thread-4036: Failed to enable GCS
# # Thread-4038: Failed to enable GCS
# # Thread-4037: Failed to enable GCS
# # Sending signals, timeout remaining: 10000ms
# # Sending signals, timeout remaining: 9900ms
    ⋮
# # Sending signals, timeout remaining: 200ms
# # Sending signals, timeout remaining: 100ms
# # Finishing up...
# # Thread-4030 exited with error code 255
# not ok 1 Thread-4030
# # Thread-4031 exited with error code 255
# not ok 2 Thread-4031
# # Thread-4032 exited with error code 255
# not ok 3 Thread-4032
# # Thread-4033 exited with error code 255
# not ok 4 Thread-4033
# # Thread-4034 exited with error code 255
# not ok 5 Thread-4034
# # Thread-4035 exited with error code 255
# not ok 6 Thread-4035
# # Thread-4036 exited with error code 255
# not ok 7 Thread-4036
# # Thread-4037 exited with error code 255
# not ok 8 Thread-4037
# # Thread-4038 exited with error code 255
# not ok 9 Thread-4038
# # Totals: pass:0 fail:9 xfail:0 xpass:0 skip:0 error:0
ok 1 selftests: arm64: gcs-stress

-- 
Thiago