[comp.sys.transputer] 3L Parallel Fortran : Processor Farms

dzahar@latcs1.oz.au (Dzaharudin Mansor) (10/08/90)

Hi,
	I'm developing a application program using the 3L
	Parallel Fortran compiler. The application is
	of the type that requires a master, and as many 
	worker tasks as possible.....hence the use of the
	Processor Farms application model using the flood-fill
	configurer.

	The problem is that I am not getting good speedup
	from 1 Transputer to 4 Transputers (only a 2X speedup
	when using 4 Transputers), and on examining 
	how the work packets are sent and result packets received,
	It seems that there are only two worker tasks in the network.

	Possible explanations:
		1. The configurer sets up only two worker tasks
		   for the 4 Transputer configuration.

		2. The master processes are scheduled in a way that
		   the use of the external worker tasks is not optimal.

	Anyone else had similar experiences?

	I would also like to seek information on:

	1. How does the flood-fill configurer determine how many
	   worker tasks that will be employed given X
	   number of Transputers.

	2. What type of scheduling does the compiler employ?
	   Time slicing? Preempt on waiting for communication?



	Any views, references, discussion (anything at all) will
	be greatly appreciated.

	Thanks.

-dzahar-