> On Aug 27, 2022, at 10:18, Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: > > On 2022/8/27 9:35, Muchun Song wrote: >> >> >>> On Aug 26, 2022, at 17:24, Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: >>> >>> If code reaches here, it's guaranteed that HPageVmemmapOptimized is set >>> for the hugetlb page (or VM_BUG_ON_PAGE() will complain about it). It's >> >> Hi Miaohe, >> >> Right. >> >>> unnecessary to set it again. >> >> No, I suppose you didn’t test this patch since it does not work. The >> HPageVmemmapOptimized is cleared in the above code of line >> (set_page_private(page, 0)). So NAck. > > Sorry, I missed that and thanks for pointing this out. Does this code deserves a > comment like below? > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index d0617d64d718..3374c1d2b52e 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1522,6 +1522,10 @@ static void add_hugetlb_page(struct hstate *h, struct page *page, > > set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); > set_page_private(page, 0); > + /* > + * We have to set HPageVmemmapOptimized again as above > + * set_page_private(page, 0) cleared it. > + */ > SetHPageVmemmapOptimized(page); I’m fine with this comment. Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > /* > > > Thanks, > Miaohe Lin
