Commit e2333dad authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
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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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarSeongJae Park <sjpark@amazon.de>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Link: https://lkml.kernel.org/r/20200908195539.25896-8-willy@infradead.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 65dfe3c3

mm/huge_memory.c

+2 −2
Original line number Diff line number Diff line
@@ -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;