Even a simple int main() { mlockall(MCL_CURRENT); fork(); } crashes, although with another errors: [ 3421.236586] thoughts2[2297]: segfault at 10e0 ip 00007f598a0275c5 sp 00007ffeec71ef50 error 4 in libc.so.6[da5c5,7f5989f73000+157000] likely on CPU 0 (core 0, socket 0) [ 3421.237280] Code: 89 c3 45 84 e4 0f 84 9a 02 00 00 e8 e5 b0 ff ff 41 89 c4 85 c0 0f 85 a2 01 00 00 48 83 05 ca 21 10 00 04 4c 8b 25 cb b9 0f 00 <49> 8b 84 24 e0 10 00 00 66 0f ef c0 49 c7 84 24 28 0a 00 00 00 00 [ 3421.957294] traps: thoughts2[2298] general protection fault ip:7f7aca1f36fd sp:7ffc6b05d6f0 error:0 in libc.so.6[3f6fd,7f7aca1da000+157000] Ingo -- const_cast<long double>(Λ)