Re: [PATCH] mm/page_alloc: Clean up check_for_memory

From: Oscar Salvador
Date: Wed Aug 29 2018 - 16:34:37 EST


On Tue, Aug 28, 2018 at 02:35:30PM -0700, Andrew Morton wrote:
> > First, we should only set N_HIGH_MEMORY in case we have
> > CONFIG_HIGHMEM.
>
> Why? Just a teeny optimization?

Hi Andrew,

Optimization was not really my point here, my point was to make
the code less subtle and more clear.
One may wonder why we set N_HIGH_MEMORY unconditionally when
__only__ CONFIG_HIGHMEM matters for this case, and why we set
N_NORMAL_MEMORY __only__ for CONFIG_HIGHMEM when we should not care
about that at all.

I do not really expect a big impact here, mainly because check_for_memory
is only being used during boot.

--
Oscar Salvador
SUSE L3