mm: memcontrol: switch to native NR_FILE_PAGES and NR_SHMEM counters
Memcg maintains private MEMCG_CACHE and NR_SHMEM counters. This
divergence from the generic VM accounting means unnecessary code overhead,
and creates a dependency for memcg that page->mapping is set up at the
time of charging, so that page types can be told apart.
Convert the generic accounting sites to mod_lruvec_page_state and friends
to maintain the per-cgroup vmstat counters of NR_FILE_PAGES and NR_SHMEM.
The page is already locked in these places, so page->mem_cgroup is stable;
we only need minimal tweaks of two mem_cgroup_migrate() calls to ensure
it's set up in time.
Then replace MEMCG_CACHE with NR_FILE_PAGES and delete the private
NR_SHMEM accounting sites.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Link: http://lkml.kernel.org/r/20200508183105.225460-10-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index 0d96157..71842fd 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -653,8 +653,8 @@ static int shmem_add_to_page_cache(struct page *page,
__inc_node_page_state(page, NR_SHMEM_THPS);
}
mapping->nrpages += nr;
- __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
- __mod_node_page_state(page_pgdat(page), NR_SHMEM, nr);
+ __mod_lruvec_page_state(page, NR_FILE_PAGES, nr);
+ __mod_lruvec_page_state(page, NR_SHMEM, nr);
unlock:
xas_unlock_irq(&xas);
} while (xas_nomem(&xas, gfp));
@@ -685,8 +685,8 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
error = shmem_replace_entry(mapping, page->index, page, radswap);
page->mapping = NULL;
mapping->nrpages--;
- __dec_node_page_state(page, NR_FILE_PAGES);
- __dec_node_page_state(page, NR_SHMEM);
+ __dec_lruvec_page_state(page, NR_FILE_PAGES);
+ __dec_lruvec_page_state(page, NR_SHMEM);
xa_unlock_irq(&mapping->i_pages);
put_page(page);
BUG_ON(error);
@@ -1593,8 +1593,9 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
xa_lock_irq(&swap_mapping->i_pages);
error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
if (!error) {
- __inc_node_page_state(newpage, NR_FILE_PAGES);
- __dec_node_page_state(oldpage, NR_FILE_PAGES);
+ mem_cgroup_migrate(oldpage, newpage);
+ __inc_lruvec_page_state(newpage, NR_FILE_PAGES);
+ __dec_lruvec_page_state(oldpage, NR_FILE_PAGES);
}
xa_unlock_irq(&swap_mapping->i_pages);
@@ -1606,7 +1607,6 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
*/
oldpage = newpage;
} else {
- mem_cgroup_migrate(oldpage, newpage);
lru_cache_add_anon(newpage);
*pagep = newpage;
}