Re: [PATCH v7 4/7] mm,hugetlb: Split prep_new_huge_page functionality

From: Oscar Salvador
Date: Wed Apr 14 2021 - 00:59:53 EST


On Tue, Apr 13, 2021 at 02:33:41PM -0700, Mike Kravetz wrote:
> > -static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
> > +/*
> > + * Must be called with the hugetlb lock held
> > + */
> > +static void __prep_account_new_huge_page(struct hstate *h, int nid)
> > +{
> > + h->nr_huge_pages++;
> > + h->nr_huge_pages_node[nid]++;
>
> I would prefer if we also move setting the destructor to this routine.
> set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);

Uhm, but that is the routine that does the accounting, it feels wrong
here, plus...

>
> That way, PageHuge() will be false until it 'really' is a huge page.
> If not, we could potentially go into that retry loop in
> dissolve_free_huge_page or alloc_and_dissolve_huge_page in patch 5.

...I do not follow here, could you please elaborate some more?
Unless I am missing something, behaviour should not be any different with this
patch.

Thanks


--
Oscar Salvador
SUSE L3