Some ASan and TSan tests go into an infinite loop on Debian/sid x86_64

Hi,

I was just building the top-of-trunk of LLVM/Clang/compiler-rt on
Debian/sid x86_64 (with gcc (Debian 5.3.1-7) 5.3.1 20160121) and for
me Asan-x86_64-inline-Test/AddressSanitizer.ManyThreadsTest does not
finish running:

Note: Google Test filter = AddressSanitizer.ManyThreadsTest
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from AddressSanitizer
[ RUN ] AddressSanitizer.ManyThreadsTest
<just keeps going for minutes>

Same for 'ThreadSanitizer :: mmap_stress.cc', but it doesn't produce any output.

The tests seem to be multithreaded, so I want to mention that this is
an 18-core VM. Maybe the tests are not scaling well?

Is this a known issue?

Dmitri

We noted on AArch64 buildbot constantly [1] so we disabled it on aarch64 for
further investigation (I haven't check it yet). Failing on x86_64 makes me
believe this is not an architecture specific issue.

[1] https://llvm.org/bugs/show_bug.cgi?id=24389

Have you tried attaching gdb to the running test and collecting the stack trace?