mm: memcontrol: switch to native NR_ANON_MAPPED counter
Memcg maintains a private MEMCG_RSS counter. 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 counter of NR_ANON_MAPPED. We use
lock_page_memcg() to stabilize page->mem_cgroup during rmap changes, the
same way we do for NR_FILE_MAPPED.
With the previous patch removing MEMCG_CACHE and the private NR_SHMEM
counter, this patch finally eliminates the need to have page->mapping set
up at charge time. However, we need to have page->mem_cgroup set up by
the time rmap runs and does the accounting, so switch the commit and the
rmap callbacks around.
v2: fix temporary accounting bug by switching rmap<->commit (Joonsoo)
Signed-off-by: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Balbir Singh <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1829fc4..01f6538 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1920,11 +1920,11 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
set_pte_at(vma->vm_mm, addr, pte,
pte_mkold(mk_pte(page, vma->vm_page_prot)));
if (page == swapcache) {
- page_add_anon_rmap(page, vma, addr, false);
mem_cgroup_commit_charge(page, memcg, true);
+ page_add_anon_rmap(page, vma, addr, false);
} else { /* ksm created a completely new copy */
- page_add_new_anon_rmap(page, vma, addr, false);
mem_cgroup_commit_charge(page, memcg, false);
+ page_add_new_anon_rmap(page, vma, addr, false);
lru_cache_add_active_or_unevictable(page, vma);
}
swap_free(entry);
