joshwilsdon

The physical memory limit and the swap cap are two independent and 
unrelated limits.

The physical memory limit is a soft cap that controls how many pages of
physical memory can be resident for the zone. Once that value is exceeded 
the memory capper will invalidate pages until the RSS of the set of
processes within the zone is below the limit. 
 
The swap cap is a hard limit and is used to control how much anonymous
memory is available. Because anonymous memory is reserved when it is