OS/161 Reference Manual


bigfork - large forking test




bigfork is a combination of the forktest and parallelvm tests. It forks geometrically like forktest, but more times (it goes six deep instead of four) and in between each it does some aimless matrix operations similar to those in parallelvm. It was written to try to come up with a test that generates lots of processes (like parallelvm) but works better as a benchmark than parallelvm does. It is only modestly successful; multiple runs of bigfork still typically give a moderately high variance; but as multiple runs of parallelvm typically exhibit a huge variance it's a step forward.

It uses about 4M of memory, which is bigger than parallelvm but comparable to some of the other VM stress tests. When run in-core it also offers a limited ability to test the multiprocessor scalability of your VM system.


bigfork uses the following system calls:

bigfork should run correctly to completion once the VM assignment is complete.