* Kirill A. Shutemov [off-list ref] wrote:

On Mon, Oct 23, 2017 at 02:40:14PM +0200, Ingo Molnar wrote:

quoted

* Kirill A. Shutemov [off-list ref] wrote:

quoted

quoted

Making a variable that 'looks' like a constant macro dynamic in a rare Kconfig 
scenario is asking for trouble.

We expect boot-time page mode switching to be enabled in kernel of next
generation enterprise distros. It shoudn't be that rare.

My point remains even with not-so-rare Kconfig dependency.

I don't follow how introducing new variable that depends on Kconfig option
would help with the situation.

A new, properly named variable or function (max_physmem_bits or 
max_physmem_bits()) that is not all uppercase would make it abundantly clear that 
it is not a constant but a runtime value.

We would end up with inverse situation: people would use MAX_PHYSMEM_BITS
where the new variable need to be used and we will in the same situation.

It should result in sub-optimal resource allocations worst-case, right?

We could also rename it to MAX_POSSIBLE_PHYSMEM_BITS to make it clear that the 
real number of bits can be lower.

Thanks,

	Ingo

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