Re: [PATCH 07/11] mm/huge_memory: Fix can_split_huge_page assumption of THP size

Huang, Ying
2020-09-16T01:45:05Z

"Matthew Wilcox (Oracle)" <willy@infradead.org> writes:

> Ask the page how many subpages it has instead of assuming it's PMD size.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> mm/huge_memory.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index e9503b10df8f..8bf8caf66923 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2546,9 +2546,9 @@ bool can_split_huge_page(struct page *page, int *pextra_pins)
>
> /* Additional pins from page cache */
> if (PageAnon(page))
> - extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
> + extra_pins = PageSwapCache(page) ? thp_nr_pages(page) : 0;
> else
> - extra_pins = HPAGE_PMD_NR;
> + extra_pins = thp_nr_pages(page);
> if (pextra_pins)
> *pextra_pins = extra_pins;
> return total_mapcount(page) == page_count(page) - extra_pins - 1;

Acked-by: "Huang, Ying" <ying.huang@intel.com>

Best Regards,
Huang, Ying