> many of those bugs have been covered up for years by the relatively friendlier x86 memory model vs weaker models like ARM I had to take a peek at a friend's

> many of those bugs have been covered up for years by the relatively friendlier x86 memory model vs weaker models like ARM I had to take a peek at a friend's Cavium's ThunderX2 kernel issue a while back, which stops having concurrency when release build is swapped with a debug build. So the specific part that drives you crazy is "Atomic can be reordered with stores - Y" for ARM and N for X86_64. And changing the compiler optimization flags can turn on/off this bug.