On Thu, Oct 29, 2020 at 7:34 PM Hillf Danton hdanton@sina.com wrote:

On Thu, 29 Oct 2020 12:34:51 -0700 John Stultz wrote:

...

As for your comment on HPAGE_PMD_ORDER (9 on arm64/arm) and PAGE_ALLOC_COSTLY_ORDER(3), I'm not totally sure I understand your question? Are you suggesting those values would be more natural orders to choose from?

The numbers, 9 and 3, are not magic themselves but under the mm diretory they draw more attentions than others do. Sometimes it would take two minutes for me to work out that HPAGE_PMD_ORDER does not mean 1MiB, on platforms like arm64 or not.

Yes, I can say it took me longer than two minutes to dig around and work out HPAGE_PMD_ORDER for my last reply. :)

Though I'm still a bit unsure if you are proposing something more than just a comment to explain why order 8 and order 4 allocations are used in my patch? Please let me know if so.

thanks -john