This limits the size of a table used for sharing information
	about collapsible entries among SMP workers. Limiting sharing
	too much results in cache content duplication and missed
	collapsing opportunities. Using excessively large values
	wastes shared memory.

	The limit should be significantly larger then the number of
	concurrent collapsible entries one wants to share. For a cache
	that handles less than 5000 concurrent requests, the default
	setting of 16384 should be plenty.

	If the limit is set to zero, it disables sharing of collapsed
	forwarding between SMP workers.