CPU-intensive Ruby/Python code runs slower on default-configured DockerSummary Docker enables security mechanism for Spectre vulnerability by default. This degrades the performance of almost all CPU-intensive programs, especially, interpreters like Ruby and Python. The execution time becomes about twice at worst. Problem This is a simple benchmark program that runs an empty loop 100M times. i=0 while i < 100_000_000 i+=1 end It takes 1.3 sec. on the host, but it does
