Re: [PATCH v3 00/21] huge page clearing optimizations

[Matthew Wilcox]

On Tue, Jun 07, 2022 at 10:56:01AM -0700, Linus Torvalds wrote:
> I worry a bit about the insanity of the "gigantic" pages, and the
> mem_map_next() games it plays, but that code is from 2008 and I really
> doubt it makes any sense to keep around at least for x86. The source
> of that abomination is powerpc, and I do not think that whole issue
> with MAX_ORDER_NR_PAGES makes any difference on x86, at least.

Oh, argh, I meant to delete mem_map_next(), and forgot.

If you need to use struct page (a later message hints you don't), just
use nth_page() directly.  I optimised it so it's not painful except on
SPARSEMEM && !SPARSEMEM_VMEMMAP back in December in commit 659508f9c936.
And nobody cares about performance on SPARSEMEM && !SPARSEMEM_VMEMMAP
systems.