This is a meaningless assertion, if you insist on going that far we have to discuss whether OS context switches cause your process to pause or whether the alloc

This is a meaningless assertion, if you insist on going that far we have to discuss whether OS context switches cause your process to pause or whether the allocator you're using causes page faults. When people say 'gc implementations that have no pauses' they mean no stop-the-world, which IS an achievable thing in production collectors in many cases.