https://bugs.freedesktop.org/show_bug.cgi?id=94410
--- Comment #8 from Timothee Besset ttimo@ttimo.net --- The freeze problems are very likely this issue: https://bugs.freedesktop.org/show_bug.cgi?id=101977
I haven't seen this allocator problem in 4.16 with ubuntu 16.x, I suspect it's tied to a clang / libstdc++ / distribution combo.