Constant MAX_SWAPFILES_SHIFT

pub const MAX_SWAPFILES_SHIFT: i32 = 5;

Available on crate feature dep_nc only.

MAX_SWAPFILES defines the maximum number of swaptypes: things which can be swapped to.

The swap type and the offset into that swap type are encoded into pte’s and into pgoff_t's in the swapcache.

Using five bits for the type means that the maximum number of swapcache pages is 27 bits on 32-bit-pgoff_t architectures.

And that assumes that the architecture packs the type/offset into the pte as 5/27 as well.