Why is TUNABLE_INT discouraged?

[Dag-Erling Smørgrav]

Garrett Cooper <gcooper at FreeBSD.org> writes:
> Why would someone express a tunable in a memory address (not being
> sarcastic... I just don't see why it makes sense right now, but if
> there's a valid reason I'm more than happy to be educated :)..)?

A few examples:

hw.acpi.host_mem_start
hw.pci.host_mem_start
hw.physmemstart

The following are not addresses, but can be > 32 bits on 64-bit machines
and even on some 32-bit machines using PAE / PTE:

hw.physmem
vm.kmem_size
vm.kmem_size_max
vm.kmem_size_min

It might be a good idea to introduce TUNABLE_POINTER and TUNABLE_SIZE.

DES
-- 
Dag-Erling Smørgrav - des at des.no