Commit 65dfe3c3 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
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mm/huge_memory: fix page_trans_huge_mapcount assumption of THP size 



Ask the page what size it is 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>
Cc: Huang Ying <ying.huang@intel.com>
Link: https://lkml.kernel.org/r/20200908195539.25896-7-willy@infradead.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8cce5475

mm/huge_memory.c

+2 −2
Original line number Diff line number Diff line
@@ -2558,14 +2558,14 @@ int page_trans_huge_mapcount(struct page *page, int *total_mapcount) 
	page = compound_head(page);



	_total_mapcount = ret = 0;

	for (i = 0; i < HPAGE_PMD_NR; i++) {

	for (i = 0; i < thp_nr_pages(page); i++) {

		mapcount = atomic_read(&page[i]._mapcount) + 1;

		ret = max(ret, mapcount);

		_total_mapcount += mapcount;

	}

	if (PageDoubleMap(page)) {

		ret -= 1;

		_total_mapcount -= HPAGE_PMD_NR;

		_total_mapcount -= thp_nr_pages(page);

	}

	mapcount = compound_mapcount(page);

	ret += mapcount;