From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: 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. Link: http://lkml.kernel.org/r/20200508183105.225460-10-hannes@xxxxxxxxxxx Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 3 +-- mm/filemap.c | 17 +++++++++-------- mm/khugepaged.c | 16 +++++++++++----- mm/memcontrol.c | 28 +++++++++++----------------- mm/migrate.c | 15 +++++++++++---- mm/shmem.c | 14 +++++++------- 6 files changed, 50 insertions(+), 43 deletions(-) --- a/include/linux/memcontrol.h~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/include/linux/memcontrol.h @@ -29,8 +29,7 @@ struct kmem_cache; /* Cgroup-specific page state, on top of universal node page state */ enum memcg_stat_item { - MEMCG_CACHE = NR_VM_NODE_STAT_ITEMS, - MEMCG_RSS, + MEMCG_RSS = NR_VM_NODE_STAT_ITEMS, MEMCG_RSS_HUGE, MEMCG_SWAP, MEMCG_SOCK, --- a/mm/filemap.c~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/mm/filemap.c @@ -199,9 +199,9 @@ static void unaccount_page_cache_page(st nr = hpage_nr_pages(page); - __mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr); + __mod_lruvec_page_state(page, NR_FILE_PAGES, -nr); if (PageSwapBacked(page)) { - __mod_node_page_state(page_pgdat(page), NR_SHMEM, -nr); + __mod_lruvec_page_state(page, NR_SHMEM, -nr); if (PageTransHuge(page)) __dec_node_page_state(page, NR_SHMEM_THPS); } else if (PageTransHuge(page)) { @@ -802,21 +802,22 @@ int replace_page_cache_page(struct page new->mapping = mapping; new->index = offset; + mem_cgroup_migrate(old, new); + xas_lock_irqsave(&xas, flags); xas_store(&xas, new); old->mapping = NULL; /* hugetlb pages do not participate in page cache accounting. */ if (!PageHuge(old)) - __dec_node_page_state(old, NR_FILE_PAGES); + __dec_lruvec_page_state(old, NR_FILE_PAGES); if (!PageHuge(new)) - __inc_node_page_state(new, NR_FILE_PAGES); + __inc_lruvec_page_state(new, NR_FILE_PAGES); if (PageSwapBacked(old)) - __dec_node_page_state(old, NR_SHMEM); + __dec_lruvec_page_state(old, NR_SHMEM); if (PageSwapBacked(new)) - __inc_node_page_state(new, NR_SHMEM); + __inc_lruvec_page_state(new, NR_SHMEM); xas_unlock_irqrestore(&xas, flags); - mem_cgroup_migrate(old, new); if (freepage) freepage(old); put_page(old); @@ -867,7 +868,7 @@ static int __add_to_page_cache_locked(st /* hugetlb pages do not participate in page cache accounting */ if (!huge) - __inc_node_page_state(page, NR_FILE_PAGES); + __inc_lruvec_page_state(page, NR_FILE_PAGES); unlock: xas_unlock_irq(&xas); } while (xas_nomem(&xas, gfp_mask & GFP_RECLAIM_MASK)); --- a/mm/khugepaged.c~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/mm/khugepaged.c @@ -1844,12 +1844,18 @@ out_unlock: } if (nr_none) { - struct zone *zone = page_zone(new_page); - - __mod_node_page_state(zone->zone_pgdat, NR_FILE_PAGES, nr_none); + struct lruvec *lruvec; + /* + * XXX: We have started try_charge and pinned the + * memcg, but the page isn't committed yet so we + * cannot use mod_lruvec_page_state(). This hackery + * will be cleaned up when remove the page->mapping + * dependency from memcg and fully charge above. + */ + lruvec = mem_cgroup_lruvec(memcg, page_pgdat(new_page)); + __mod_lruvec_state(lruvec, NR_FILE_PAGES, nr_none); if (is_shmem) - __mod_node_page_state(zone->zone_pgdat, - NR_SHMEM, nr_none); + __mod_lruvec_state(lruvec, NR_SHMEM, nr_none); } xa_locked: --- a/mm/memcontrol.c~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/mm/memcontrol.c @@ -842,11 +842,6 @@ static void mem_cgroup_charge_statistics */ if (PageAnon(page)) __mod_memcg_state(memcg, MEMCG_RSS, nr_pages); - else { - __mod_memcg_state(memcg, MEMCG_CACHE, nr_pages); - if (PageSwapBacked(page)) - __mod_memcg_state(memcg, NR_SHMEM, nr_pages); - } if (abs(nr_pages) > 1) { VM_BUG_ON_PAGE(!PageTransHuge(page), page); @@ -1392,7 +1387,7 @@ static char *memory_stat_format(struct m (u64)memcg_page_state(memcg, MEMCG_RSS) * PAGE_SIZE); seq_buf_printf(&s, "file %llu\n", - (u64)memcg_page_state(memcg, MEMCG_CACHE) * + (u64)memcg_page_state(memcg, NR_FILE_PAGES) * PAGE_SIZE); seq_buf_printf(&s, "kernel_stack %llu\n", (u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) * @@ -3357,7 +3352,7 @@ static unsigned long mem_cgroup_usage(st unsigned long val; if (mem_cgroup_is_root(memcg)) { - val = memcg_page_state(memcg, MEMCG_CACHE) + + val = memcg_page_state(memcg, NR_FILE_PAGES) + memcg_page_state(memcg, MEMCG_RSS); if (swap) val += memcg_page_state(memcg, MEMCG_SWAP); @@ -3828,7 +3823,7 @@ static int memcg_numa_stat_show(struct s #endif /* CONFIG_NUMA */ static const unsigned int memcg1_stats[] = { - MEMCG_CACHE, + NR_FILE_PAGES, MEMCG_RSS, MEMCG_RSS_HUGE, NR_SHMEM, @@ -5461,6 +5456,14 @@ static int mem_cgroup_move_account(struc lock_page_memcg(page); if (!PageAnon(page)) { + __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); + __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); + + if (PageSwapBacked(page)) { + __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); + __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); + } + if (page_mapped(page)) { __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); @@ -6673,10 +6676,8 @@ struct uncharge_gather { unsigned long nr_pages; unsigned long pgpgout; unsigned long nr_anon; - unsigned long nr_file; unsigned long nr_kmem; unsigned long nr_huge; - unsigned long nr_shmem; struct page *dummy_page; }; @@ -6700,9 +6701,7 @@ static void uncharge_batch(const struct local_irq_save(flags); __mod_memcg_state(ug->memcg, MEMCG_RSS, -ug->nr_anon); - __mod_memcg_state(ug->memcg, MEMCG_CACHE, -ug->nr_file); __mod_memcg_state(ug->memcg, MEMCG_RSS_HUGE, -ug->nr_huge); - __mod_memcg_state(ug->memcg, NR_SHMEM, -ug->nr_shmem); __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_pages); memcg_check_events(ug->memcg, ug->dummy_page); @@ -6743,11 +6742,6 @@ static void uncharge_page(struct page *p ug->nr_huge += nr_pages; if (PageAnon(page)) ug->nr_anon += nr_pages; - else { - ug->nr_file += nr_pages; - if (PageSwapBacked(page)) - ug->nr_shmem += nr_pages; - } ug->pgpgout++; } else { ug->nr_kmem += nr_pages; --- a/mm/migrate.c~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/mm/migrate.c @@ -490,11 +490,18 @@ int migrate_page_move_mapping(struct add * are mapped to swap space. */ if (newzone != oldzone) { - __dec_node_state(oldzone->zone_pgdat, NR_FILE_PAGES); - __inc_node_state(newzone->zone_pgdat, NR_FILE_PAGES); + struct lruvec *old_lruvec, *new_lruvec; + struct mem_cgroup *memcg; + + memcg = page_memcg(page); + old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat); + new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat); + + __dec_lruvec_state(old_lruvec, NR_FILE_PAGES); + __inc_lruvec_state(new_lruvec, NR_FILE_PAGES); if (PageSwapBacked(page) && !PageSwapCache(page)) { - __dec_node_state(oldzone->zone_pgdat, NR_SHMEM); - __inc_node_state(newzone->zone_pgdat, NR_SHMEM); + __dec_lruvec_state(old_lruvec, NR_SHMEM); + __inc_lruvec_state(new_lruvec, NR_SHMEM); } if (dirty && mapping_cap_account_dirty(mapping)) { __dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY); --- a/mm/shmem.c~mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters +++ a/mm/shmem.c @@ -653,8 +653,8 @@ next: __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 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 pag 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 pag */ oldpage = newpage; } else { - mem_cgroup_migrate(oldpage, newpage); lru_cache_add_anon(newpage); *pagep = newpage; } _
