About z3fold page migration

Quoted 4 lines · linmiaohe

Hi all:

	Many thanks for brilliant z3fold code. I am reading it and have some questions about it. It's very nice of you if you can explain it for me.
	1.page->private is used in z3fold but PagePrivate flag is never set, should we SetPagePrivate for it?

No. SetPagePrivate and page->private are related in interesting and complicated ways. I'm working on some documentation for it at the moment, but the short answer is: no.

Quoted 2 lines

2.Since PagePrivate flag is never set, why we ClearPagePrivate in free_z3fold_page and z3fold_page_migrate?

That's probably a bug.

Quoted 2 lines

3.Should we add page to the unbuddied list in z3fold_page_putback()
when zhdr->refcount does not reach 0 since we remove it from unbuddied list in z3fold_page_isolate? Or When we will add page to the unbuddied list after z3fold_page_putback?

This one I do not know the answer to.