On Friday, October 28, 2016 1:56 PM Huang, Ying wrote:
> @@ -2016,10 +2021,12 @@ int page_trans_huge_mapcount(struct page *page, int
> *total_mapcount)
> /* Racy check whether the huge page can be split */
> bool can_split_huge_page(struct page *page)
> {
> - int extra_pins = 0;
> + int extra_pins;
>
> /* Additional pins from radix tree */
> - if (!PageAnon(page))
> + if (PageAnon(page))
> + extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
> + else
> extra_pins = HPAGE_PMD_NR;
extra_pins is computed in this newly added helper.
> return total_mapcount(page) == page_count(page) - extra_pins - 1;
> }
> @@ -2072,7 +2079,7 @@ int split_huge_page_to_list(struct page *page, struct
> list_head *list)
> ret = -EBUSY;
> goto out;
> }
> - extra_pins = 0;
> + extra_pins = PageSwapCache(head) ? HPAGE_PMD_NR : 0;
It is also computed at the call site, so can we fold them into one?
> mapping = NULL;
> anon_vma_lock_write(anon_vma);
> } else {
> --
> 2.9.3
