Commit f7da677b authored Aug 24, 2019 by Vlastimil Babka Committed by Linus Torvalds Aug 24, 2019

mm, page_owner: handle THP splits correctly

THP splitting path is missing the split_page_owner() call that
split_page() has.

As a result, split THP pages are wrongly reported in the page_owner file
as order-9 pages.  Furthermore when the former head page is freed, the
remaining former tail pages are not listed in the page_owner file at
all.  This patch fixes that by adding the split_page_owner() call into
__split_huge_page().

Link: http://lkml.kernel.org/r/20190820131828.22684-2-vbabka@suse.cz


Fixes: a9627bc5 ("mm/page_owner: introduce split_page_owner and replace manual handling")
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 46d0b24c

mm/huge_memory.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#include <linux/shmem_fs.h>
		#include <linux/oom.h>
		#include <linux/numa.h>
		#include <linux/page_owner.h>

		#include <asm/tlb.h>
		#include <asm/pgalloc.h>
		@@ -2516,6 +2517,9 @@ static void __split_huge_page(struct page page, struct list_head list,
		}

		ClearPageCompound(head);

		split_page_owner(head, HPAGE_PMD_ORDER);

		/* See comment in __split_huge_page_tail() */
		if (PageAnon(head)) {
		/* Additional pin to swap cache */

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