[Nottingham] Opportunistically maximising resource utilisation

[Camilo Mesias]

> Two crazy but simple plausible examples:

These rely on disk or RAM usage to cause problems. If we accept that
priority solves the CPU problem then all we need is a solution for RAM
and one for disk.

RAM is strange because a virtual memory process can't really grow
indefinitely, and IIRC freed memory (freed at the malloc/free level)
is never garbage collected (at the virtual memory level) so the
process space remains large with areas of RAM swapped out. If we
assume that you will arrange to have plenty of swap - because disk is
cheap compared to RAM - then the solution is probably to limit the
upper memory used by the program to something that will fit on the
platform. I think this is best done by tuning or configuring the
program appropriately. IE. to use an amount of RAM that the system can
provide.

As for disk, I hear there is tunable io scheduling in the 2.6 kernel -
this could be used to put the application in a lower class of disk
users, and hopefully let the rest of the system work normally.