mm/huge_memory: fix can_split_huge_page assumption of THP size

Ask the page how many subpages it has instead of assuming it's PMD size. Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: SeongJae Park <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Acked-by: "Huang, Ying" <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
akvadrako · Oct 16, 2020 · e2333da · e2333da
1 parent 65dfe3c
commit e2333da
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
@@ -2582,9 +2582,9 @@ 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;