Measure response time of PR server for a full build and histogram:

$ cut -d":" -f3 ../../prserv-full-build-1.log | cut -d" " -f2 | cut -c -4 | sort |uniq -c
     14 0.02
     26 0.03
     22 0.04
     20 0.05
     24 0.06
      8 0.07
      4 0.08
      2 0.09
      2 0.11
      2 0.12
      2 0.34

for a simple build adding "stress -c 24" to run in parallel, adds 0.02 sec to the average PR server response time.

$ cat prserv-idle.log | cut -d":" -f3 | cut -d" " -f2  | st --avg --sd
mean	stddev
0.0566617	0.0230208

$ cat prserv-idle-2.log | cut -d":" -f3 | cut -d" " -f2  | st --avg --sd
mean	stddev
0.0544475	0.0211526

$ cat prserv-cpu-24-3.log | cut -d":" -f3 | cut -d" " -f2  | st --avg --sd
mean	stddev
0.0769975	0.0240502