strace: Process 4501 attached with 15 threads
strace: Process 4501 detached
strace: Process 4502 detached
strace: Process 4503 detached
strace: Process 4504 detached
strace: Process 4505 detached
strace: Process 4507 detached
strace: Process 4508 detached
strace: Process 4525 detached
strace: Process 4526 detached
strace: Process 4527 detached
strace: Process 4589 detached
strace: Process 4590 detached
strace: Process 4591 detached
strace: Process 4592 detached
strace: Process 4808 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 65.79    6.683671          73     91395     11481 futex
 22.77    2.313161       13527       171           epoll_wait
 11.23    1.140667      285167         4         4 restart_syscall
  0.19    0.019226           1     25197           select
  0.02    0.001911           0      5337           sched_yield
  0.00    0.000000           0       196        32 read
  0.00    0.000000           0        59           write
  0.00    0.000000           0        12           open
  0.00    0.000000           0        20           close
  0.00    0.000000           0         3           fstat
  0.00    0.000000           0         4           lstat
  0.00    0.000000           0         3           mmap
  0.00    0.000000           0         3           munmap
  0.00    0.000000           0      1175           pread64
  0.00    0.000000           0         8           getdents64
  0.00    0.000000           0         8           openat
  0.00    0.000000           0         4           renameat
------ ----------- ----------- --------- --------- ----------------
100.00   10.158636                123599     11517 total