v2:
autoload PerfDataHelper functions
Keep loadavg in shared memory
Guard loadavg access by a mutex
Initialize loadavg to the current load
v3:
Shared memory version bump isn't needed if we are only extending it
Remove unused autoload
Mark inititalized flags as NO_COPY for correct behaviour in fork child
Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>