But there is a general problem of larger pages in systems that

don't support them natively (in hardware) depending in how it's

implemented the memory manager in the kernel:
   "Doubling the soft page size implies

      halfing the TLB soft-entries in the old hardware".
   "x4 soft page size=> 1/4 TLB soft-entries, ... and so on."
Assuming one soft double-sized page represents 2 real-sized pages,

one replacing of one soft double-sized page implies replacing

2 TLB's entries containing the 2 real-sized pages.
The TLB is very small, its entries are around 24 entries aprox. in

some processors!.
Assuming soft 64 KiB page using real 4 KiB pages => 1/16 TLB soft-entries.

If the TLB has 24 entries then calculating 24/16=1.5 soft-entries,

   the TLB will have only 1 soft-entry for soft 64 KiB pages!!! Weird!!!
The normal soft sizes are 8 KiB or 16 KiB for non-native processors, not more.

  So, the TLB of 24 entries of real 4 KiB will have 12 or 6

soft-entries respect.

--

That's not a problem, actually, since the TLB entries can get shuffled

like any other (for software TLBs it's a little different, but it can be

dealt with there too.)
The *real* problem is ABI breakage.
	-hpa

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