On Mon, Jun 24, 2019 at 01:34:01PM +0800, Pingfan Liu wrote: > On Mon, Jun 24, 2019 at 1:32 PM Pingfan Liu <[email protected]> wrote: > > > > On Mon, Jun 24, 2019 at 12:43 PM Ira Weiny <[email protected]> wrote: > > > > > > On Mon, Jun 24, 2019 at 12:12:41PM +0800, Pingfan Liu wrote: > > > > Both hugetlb and thp locate on the same migration type of pageblock, > > > > since > > > > they are allocated from a free_list[]. Based on this fact, it is enough > > > > to > > > > check on a single subpage to decide the migration type of the whole huge > > > > page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on x86, > > > > similar on other archs. > > > > > > > > Furthermore, when executing isolate_huge_page(), it avoid taking global > > > > hugetlb_lock many times, and meanless remove/add to the local link list > > > > cma_page_list. > > > > > > > > Signed-off-by: Pingfan Liu <[email protected]> > > > > Cc: Andrew Morton <[email protected]> > > > > Cc: Ira Weiny <[email protected]> > > > > Cc: Mike Rapoport <[email protected]> > > > > Cc: "Kirill A. Shutemov" <[email protected]> > > > > Cc: Thomas Gleixner <[email protected]> > > > > Cc: John Hubbard <[email protected]> > > > > Cc: "Aneesh Kumar K.V" <[email protected]> > > > > Cc: Christoph Hellwig <[email protected]> > > > > Cc: Keith Busch <[email protected]> > > > > Cc: Mike Kravetz <[email protected]> > > > > Cc: [email protected] > > > > --- > > > > mm/gup.c | 19 ++++++++++++------- > > > > 1 file changed, 12 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/mm/gup.c b/mm/gup.c > > > > index ddde097..544f5de 100644 > > > > --- a/mm/gup.c > > > > +++ b/mm/gup.c > > > > @@ -1342,19 +1342,22 @@ static long check_and_migrate_cma_pages(struct > > > > task_struct *tsk, > > > > LIST_HEAD(cma_page_list); > > > > > > > > check_again: > > > > - for (i = 0; i < nr_pages; i++) { > > > > + for (i = 0; i < nr_pages;) { > > > > + > > > > + struct page *head = compound_head(pages[i]); > > > > + long step = 1; > > > > + > > > > + if (PageCompound(head)) > > > > + step = compound_order(head) - (pages[i] - head); > > > > > > Sorry if I missed this last time. compound_order() is not correct here. > > For thp, prep_transhuge_page()->prep_compound_page()->set_compound_order(). > > For smaller hugetlb, > > prep_new_huge_page()->prep_compound_page()->set_compound_order(). > > For gigantic page, prep_compound_gigantic_page()->set_compound_order(). > > > > Do I miss anything? > > > Oh, got it. It should be 1<<compound_order(head)
Yea. Ira > > Thanks, > > Pingfan > > [...]
