The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f7da677bc6e72033f0981b9d58b5c5d409fa641e Mon Sep 17 00:00:00 2001

From: Vlastimil Babka vbabka@suse.cz Date: Sat, 24 Aug 2019 17:54:59 -0700 Subject: [PATCH] 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: a9627bc5e34e ("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

diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 738065f765ab..de1f15969e27 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -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 */