Charles is working on this.
Any allocation done outside of the luajit allocator can run into an issue where that memory might be allocated above the bottom 47-bits that LuaJIT can address, for example some C code executing(allocating) via the LuaJIT FFI.
When LuaJIT tries to access such memory it will overwrite the higher bits in the pointer and access the wrong memory.
Zheng Xu is working on getting NGINX working with ARM64 jit enabled.
Zheng Xu is working on setting up a Linaro CI loop and has written a dashboard http://64.28.99.85/ that includes per-patch performance information.
Charles will start to look at this.