Best way to force a process preempt (for troubleshooting)

[Matthew Hagerty]

Greetings,

I'm trying to test for the possibility of interleaved data when two more
more processes are writing to a pipe and more than PIPE_BUF bytes need
to be written.  How can I make a situation where this scenario can be
caused reliably so I can make my test case, then apply my patch and make
sure the changes worked?  Additionally, in one case the processes are
created from fork() and in another case they are threads (not sure if
this makes any difference to the scheduler.)

Any insight would be greatly appreciated.

Thank you,
Matthew