Real < User time? How is that possible?

[pierrezaza]

So I'm observing the improvements brought by parallelising the inner loop of the julia frame render function. It's definitely quicker, but I find it very confusing that when using the timer I get a user time far greater than the real or system times. Is that normal? I thought I should get real = user + sys or real > user + sys

dyn1190-41:hpce-2016-cw1-pva13 Pierre$ time bin/julia -engine parallel_inner -max-iter 1000000
....:::::::::::::::::::::::::::::::::::::::::::::::::::::...
..:::::::::::::::::::::::::::::::::::::::::::::::::::::::::.
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:::::::::::::::::::::::::::::::-----------------::::::::::::
::::::::::::::::::::::::-----------------------------:::::::
::::::::::::::::::::---------============---------------::::
::::::::::::::::---------====+**  *+++=========-----------::
::::::::::::----------=====+*#     =***+++==========-------:
:::::::::-----------======+#       *@%%   #**+++**#%+===----
:::::::-----------======++*#@=       %    :%%%%%:  =#++===--
:::::-----------====+++++*##@                  #      #*+==-
:::-----------===+++++**#%%@.+                           *+=
::---------===+* %#####.     %                             =
:--------===++*=   =:..+     =                    -  .#*++==
------====+++**      .                       *-  %%% *+====-
----====++***#%                               %#***++====---
--====+* %%%  -*                       .      **+++====-----
-==++*#.  -                    =     +..:=   =*++===--------
-=                             %     .#####% *+===---------:
-=+*                           +.@%%#**+++++===-----------::
--==+*#      #                  @##*+++++====-----------::::
---===++#=  :%%%%%:    %       =@#*++======-----------::::::
:----===+%#**+++**#   %%@*       #+======-----------::::::::
::-------==========+++***=     #*+=====----------:::::::::::
:::-----------=========+++*  **+====---------:::::::::::::::
:::::---------------============---------:::::::::::::::::::
::::::::-----------------------------:::::::::::::::::::::::
:::::::::::::-----------------::::::::::::::::::::::::::::::
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
..:::::::::::::::::::::::::::::::::::::::::::::::::::::::::.

real    0m0.667s
user    0m4.234s
sys 0m0.024s

[m8pple]

User time is the total time spent on behalf of the user across all CPUs, while
real time is wall-clock time. So if user time is higher than real time, that means
you are making use of multiple threads in some way.

So you have 4.234 / 0.667 = 6.34. I'm guessing that means you have 8 CPUs?