you could try running it with the linux perf command. `perf stat -d java ...` if your CPU supports performance counters it should give you L1 cache misses/bra

you could try running it with the linux perf command. `perf stat -d java ...` if your CPU supports performance counters it should give you L1 cache misses/branch misses/etc. that might give you some insight into what is different between the runs. someone else mentioned it could be the memory alignment. i think java might allocate with 8 byte alignment and maybe something funny goes on with the L1-caching if the bitset allocation is not 16 byte or 32 byte aligned. if you are running it within docker you might need to use: ` --security-opt seccomp:unconfined --cap-add SYS_PTRACE --cap-add CAP_SYS_ADMIN`