Slow test result on wait4 syscall in Red Hat Enterprise Linux

Issue

• RHEL 6.6

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
99.89  331.677056        5257     63095     21035 wait4
  0.02    0.067277           0   3048327           rt_sigaction
  0.01    0.048489           0   1698666           read

• RHEL 7.9

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
92.35  596.241344        9449     63099     21039 wait4
  1.50    9.678854           3   3048331           rt_sigaction
  0.01    0.048489           0   1698666           read