From owner-freebsd-hackers@FreeBSD.ORG  Mon Aug  9 08:11:16 2010
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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Garrett Cooper <gcooper@FreeBSD.org>
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Date: Mon, 09 Aug 2010 10:11:14 +0200
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	(Garrett Cooper's message of "Sun, 8 Aug 2010 02:31:44 -0700")
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Cc: freebsd-hackers@freebsd.org, Ivan Voras <ivoras@freebsd.org>
Subject: Re: Why is TUNABLE_INT discouraged?
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Garrett Cooper <gcooper@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
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no