[llvm-dev] Unstable UBSan tests on AArch64

[Renato Golin via llvm-dev]

Hi Adhemerval,

Some UBSan tests are timing out randomly.

http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full

ex:
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/902
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/894
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/906
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/902

The timeout happens consistently here:

PASS: UBSan-TSan-aarch64 :: TestCases/Misc/enum.cpp (25310 of 25316)
PASS: UBSan-TSan-aarch64 :: TestCases/TypeCheck/null.cpp (25311 of 25316)
PASS: UBSan-TSan-aarch64 ::
TestCases/TypeCheck/vptr-virtual-base-construction.cpp (25312 of
25316)
PASS: UBSan-TSan-aarch64 :: TestCases/TypeCheck/vptr-virtual-base.cpp
(25313 of 25316)
PASS: UBSan-TSan-aarch64 :: TestCases/TypeCheck/misaligned.cpp (25314 of 25316)
PASS: UBSan-TSan-aarch64 :: TestCases/Integer/shift.cpp (25315 of 25316)

command timed out: 1200 seconds without output running ['ninja',
'check-all', '-j8'], attempting to kill

I can imagine two scenarios:

 1. The test takes a long time to run, close to the timeout, so that
it's too long some times, and others not.
 2. There is a random codegen/instrumentation problem that only shows
some times. Address randomization could be an issue, here.

I've moved it to the silent build master for now:

http://lab.llvm.org:8014/builders/clang-cmake-aarch64-full

cheers,
--renato