| Message ID | cec7c09d-5874-e160-ada6-6e10ee48784@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/shmem: shmem_replace_page() remember NR_SHMEM | expand |
On Wed, Aug 10, 2022 at 10:06:33PM -0700, Hugh Dickins wrote: > 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. > > Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > This is not terribly important, and will clash with one of Matthew's > 59 for 5.21; I don't mind if this gets delayed, and we just do it again > on top of his series later, or he fold the equivalent into his series; > but thought I'd better send it in as another fix to shmem_replace_page() > while that function is on our minds. Let's get this into 6.0 since it's a bugfix, and I'll rebase my patches for 6.1 on top of it.
--- 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);
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. Signed-off-by: Hugh Dickins <hughd@google.com> --- This is not terribly important, and will clash with one of Matthew's 59 for 5.21; I don't mind if this gets delayed, and we just do it again on top of his series later, or he fold the equivalent into his series; but thought I'd better send it in as another fix to shmem_replace_page() while that function is on our minds. mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+)