From: Hugh Dickins <hughd@google.com>
Date: Thu, 11 Aug 2022 05:06:33 +0000 (-0700)
Subject: mm/shmem: shmem_replace_page() remember NR_SHMEM
X-Git-Tag: v6.1-rc5~545^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=76d36dea02691a8ffa8cd7368eecbf727b8a1c0c;p=platform%2Fkernel%2Flinux-starfive.git

mm/shmem: shmem_replace_page() remember NR_SHMEM

Elsewhere, NR_SHMEM is updated at the same time as shmem NR_FILE_PAGES;
but shmem_replace_page() was forgetting to do that - so NR_SHMEM stats
could grow too big or too small, in those unusual cases when it's used.

Link: https://lkml.kernel.org/r/cec7c09d-5874-e160-ada6-6e10ee48784@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Radoslaw Burny <rburny@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/shmem.c b/mm/shmem.c
index ce20907..d075dd2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1659,7 +1659,9 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 		new = page_folio(newpage);
 		mem_cgroup_migrate(old, new);
 		__inc_lruvec_page_state(newpage, NR_FILE_PAGES);
+		__inc_lruvec_page_state(newpage, NR_SHMEM);
 		__dec_lruvec_page_state(oldpage, NR_FILE_PAGES);
+		__dec_lruvec_page_state(oldpage, NR_SHMEM);
 	}
 	xa_unlock_irq(&swap_mapping->i_pages);