[Beowulf] Definition of HPC

[Mark Hahn]

> If you have looked into it,  sudo echo 3 > /proc/sys/vm/drop_caches is well nigh impossible.
> But you can run an suid  C program which does effectively the same job.

"sudo sysctl -w vm.drop_caches=3" is the smarter way to do it,
or a fixed executable with sudo.  or a fixed executable with suid.
or better yet: have the system do it when appropriate, 
since inappropriate drop_caches could cause problems.