From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: 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) Link: http://lkml.kernel.org/r/20200508183105.225460-11-hannes@xxxxxxxxxxx Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> 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 -- kernel/events/uprobes.c | 2 - mm/huge_memory.c | 2 - mm/khugepaged.c | 2 - mm/memcontrol.c | 27 ++++++-------------- mm/memory.c | 10 +++---- mm/migrate.c | 2 - mm/rmap.c | 47 +++++++++++++++++++++-------------- mm/swapfile.c | 4 +- mm/userfaultfd.c | 2 - 10 files changed, 51 insertions(+), 50 deletions(-) --- a/include/linux/memcontrol.h~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ 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_RSS = NR_VM_NODE_STAT_ITEMS, - MEMCG_RSS_HUGE, + MEMCG_RSS_HUGE = NR_VM_NODE_STAT_ITEMS, MEMCG_SWAP, MEMCG_SOCK, /* XXX: why are these zone and not node counters? */ --- a/kernel/events/uprobes.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/kernel/events/uprobes.c @@ -188,8 +188,8 @@ static int __replace_page(struct vm_area if (new_page) { get_page(new_page); - page_add_new_anon_rmap(new_page, vma, addr, false); mem_cgroup_commit_charge(new_page, memcg, false); + page_add_new_anon_rmap(new_page, vma, addr, false); lru_cache_add_active_or_unevictable(new_page, vma); } else /* no new page, just dec_mm_counter for old_page */ --- a/mm/huge_memory.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/huge_memory.c @@ -640,8 +640,8 @@ static vm_fault_t __do_huge_pmd_anonymou entry = mk_huge_pmd(page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - page_add_new_anon_rmap(page, vma, haddr, true); mem_cgroup_commit_charge(page, memcg, false); + page_add_new_anon_rmap(page, vma, haddr, true); lru_cache_add_active_or_unevictable(page, vma); pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); --- a/mm/khugepaged.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/khugepaged.c @@ -1175,8 +1175,8 @@ static void collapse_huge_page(struct mm spin_lock(pmd_ptl); BUG_ON(!pmd_none(*pmd)); - page_add_new_anon_rmap(new_page, vma, address, true); mem_cgroup_commit_charge(new_page, memcg, false); + page_add_new_anon_rmap(new_page, vma, address, true); count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1); lru_cache_add_active_or_unevictable(new_page, vma); pgtable_trans_huge_deposit(mm, pmd, pgtable); --- a/mm/memcontrol.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/memcontrol.c @@ -836,13 +836,6 @@ static void mem_cgroup_charge_statistics struct page *page, int nr_pages) { - /* - * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is - * counted as CACHE even if it's on ANON LRU. - */ - if (PageAnon(page)) - __mod_memcg_state(memcg, MEMCG_RSS, nr_pages); - if (abs(nr_pages) > 1) { VM_BUG_ON_PAGE(!PageTransHuge(page), page); __mod_memcg_state(memcg, MEMCG_RSS_HUGE, nr_pages); @@ -1384,7 +1377,7 @@ static char *memory_stat_format(struct m */ seq_buf_printf(&s, "anon %llu\n", - (u64)memcg_page_state(memcg, MEMCG_RSS) * + (u64)memcg_page_state(memcg, NR_ANON_MAPPED) * PAGE_SIZE); seq_buf_printf(&s, "file %llu\n", (u64)memcg_page_state(memcg, NR_FILE_PAGES) * @@ -3353,7 +3346,7 @@ static unsigned long mem_cgroup_usage(st if (mem_cgroup_is_root(memcg)) { val = memcg_page_state(memcg, NR_FILE_PAGES) + - memcg_page_state(memcg, MEMCG_RSS); + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap) val += memcg_page_state(memcg, MEMCG_SWAP); } else { @@ -3824,7 +3817,7 @@ static int memcg_numa_stat_show(struct s static const unsigned int memcg1_stats[] = { NR_FILE_PAGES, - MEMCG_RSS, + NR_ANON_MAPPED, MEMCG_RSS_HUGE, NR_SHMEM, NR_FILE_MAPPED, @@ -5455,7 +5448,12 @@ static int mem_cgroup_move_account(struc lock_page_memcg(page); - if (!PageAnon(page)) { + if (PageAnon(page)) { + if (page_mapped(page)) { + __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); + __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); + } + } else { __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); @@ -6589,7 +6587,6 @@ void mem_cgroup_commit_charge(struct pag { unsigned int nr_pages = hpage_nr_pages(page); - VM_BUG_ON_PAGE(!page->mapping, page); VM_BUG_ON_PAGE(PageLRU(page) && !lrucare, page); if (mem_cgroup_disabled()) @@ -6662,8 +6659,6 @@ int mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg; int ret; - VM_BUG_ON_PAGE(!page->mapping, page); - ret = mem_cgroup_try_charge(page, mm, gfp_mask, &memcg); if (ret) return ret; @@ -6675,7 +6670,6 @@ struct uncharge_gather { struct mem_cgroup *memcg; unsigned long nr_pages; unsigned long pgpgout; - unsigned long nr_anon; unsigned long nr_kmem; unsigned long nr_huge; struct page *dummy_page; @@ -6700,7 +6694,6 @@ 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_RSS_HUGE, -ug->nr_huge); __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_pages); @@ -6740,8 +6733,6 @@ static void uncharge_page(struct page *p if (!PageKmemcg(page)) { if (PageTransHuge(page)) ug->nr_huge += nr_pages; - if (PageAnon(page)) - ug->nr_anon += nr_pages; ug->pgpgout++; } else { ug->nr_kmem += nr_pages; --- a/mm/memory.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/memory.c @@ -2710,8 +2710,8 @@ static vm_fault_t wp_page_copy(struct vm * thread doing COW. */ ptep_clear_flush_notify(vma, vmf->address, vmf->pte); - page_add_new_anon_rmap(new_page, vma, vmf->address, false); mem_cgroup_commit_charge(new_page, memcg, false); + page_add_new_anon_rmap(new_page, vma, vmf->address, false); lru_cache_add_active_or_unevictable(new_page, vma); /* * We call the notify macro here because, when using secondary @@ -3243,12 +3243,12 @@ vm_fault_t do_swap_page(struct vm_fault /* ksm created a completely new copy */ if (unlikely(page != swapcache && swapcache)) { - page_add_new_anon_rmap(page, vma, vmf->address, false); mem_cgroup_commit_charge(page, memcg, false); + page_add_new_anon_rmap(page, vma, vmf->address, false); lru_cache_add_active_or_unevictable(page, vma); } else { - do_page_add_anon_rmap(page, vma, vmf->address, exclusive); mem_cgroup_commit_charge(page, memcg, true); + do_page_add_anon_rmap(page, vma, vmf->address, exclusive); activate_page(page); } @@ -3390,8 +3390,8 @@ static vm_fault_t do_anonymous_page(stru } inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, vmf->address, false); mem_cgroup_commit_charge(page, memcg, false); + page_add_new_anon_rmap(page, vma, vmf->address, false); lru_cache_add_active_or_unevictable(page, vma); setpte: set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); @@ -3652,8 +3652,8 @@ vm_fault_t alloc_set_pte(struct vm_fault /* copy-on-write page */ if (write && !(vma->vm_flags & VM_SHARED)) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, vmf->address, false); mem_cgroup_commit_charge(page, memcg, false); + page_add_new_anon_rmap(page, vma, vmf->address, false); lru_cache_add_active_or_unevictable(page, vma); } else { inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page)); --- a/mm/migrate.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/migrate.c @@ -2832,8 +2832,8 @@ static void migrate_vma_insert_page(stru goto unlock_abort; inc_mm_counter(mm, MM_ANONPAGES); - 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); if (!is_zone_device_page(page)) lru_cache_add_active_or_unevictable(page, vma); get_page(page); --- a/mm/rmap.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/rmap.c @@ -1114,6 +1114,11 @@ void do_page_add_anon_rmap(struct page * bool compound = flags & RMAP_COMPOUND; bool first; + if (unlikely(PageKsm(page))) + lock_page_memcg(page); + else + VM_BUG_ON_PAGE(!PageLocked(page), page); + if (compound) { atomic_t *mapcount; VM_BUG_ON_PAGE(!PageLocked(page), page); @@ -1134,12 +1139,13 @@ void do_page_add_anon_rmap(struct page * */ if (compound) __inc_node_page_state(page, NR_ANON_THPS); - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr); } - if (unlikely(PageKsm(page))) - return; - VM_BUG_ON_PAGE(!PageLocked(page), page); + if (unlikely(PageKsm(page))) { + unlock_page_memcg(page); + return; + } /* address might be in next vma when migration races vma_adjust */ if (first) @@ -1181,7 +1187,7 @@ void page_add_new_anon_rmap(struct page /* increment count (starts at -1) */ atomic_set(&page->_mapcount, 0); } - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr); __page_set_anon_rmap(page, vma, address, 1); } @@ -1230,13 +1236,12 @@ static void page_remove_file_rmap(struct int i, nr = 1; VM_BUG_ON_PAGE(compound && !PageHead(page), page); - lock_page_memcg(page); /* Hugepages are not counted in NR_FILE_MAPPED for now. */ if (unlikely(PageHuge(page))) { /* hugetlb pages are always mapped with pmds */ atomic_dec(compound_mapcount_ptr(page)); - goto out; + return; } /* page still mapped by someone else? */ @@ -1246,14 +1251,14 @@ static void page_remove_file_rmap(struct nr++; } if (!atomic_add_negative(-1, compound_mapcount_ptr(page))) - goto out; + return; if (PageSwapBacked(page)) __dec_node_page_state(page, NR_SHMEM_PMDMAPPED); else __dec_node_page_state(page, NR_FILE_PMDMAPPED); } else { if (!atomic_add_negative(-1, &page->_mapcount)) - goto out; + return; } /* @@ -1265,8 +1270,6 @@ static void page_remove_file_rmap(struct if (unlikely(PageMlocked(page))) clear_page_mlock(page); -out: - unlock_page_memcg(page); } static void page_remove_anon_compound_rmap(struct page *page) @@ -1310,7 +1313,7 @@ static void page_remove_anon_compound_rm clear_page_mlock(page); if (nr) - __mod_node_page_state(page_pgdat(page), NR_ANON_MAPPED, -nr); + __mod_lruvec_page_state(page, NR_ANON_MAPPED, -nr); } /** @@ -1322,22 +1325,28 @@ static void page_remove_anon_compound_rm */ void page_remove_rmap(struct page *page, bool compound) { - if (!PageAnon(page)) - return page_remove_file_rmap(page, compound); + lock_page_memcg(page); - if (compound) - return page_remove_anon_compound_rmap(page); + if (!PageAnon(page)) { + page_remove_file_rmap(page, compound); + goto out; + } + + if (compound) { + page_remove_anon_compound_rmap(page); + goto out; + } /* page still mapped by someone else? */ if (!atomic_add_negative(-1, &page->_mapcount)) - return; + goto out; /* * We use the irq-unsafe __{inc|mod}_zone_page_stat because * these counters are not modified in interrupt context, and * pte lock(a spinlock) is held, which implies preemption disabled. */ - __dec_node_page_state(page, NR_ANON_MAPPED); + __dec_lruvec_page_state(page, NR_ANON_MAPPED); if (unlikely(PageMlocked(page))) clear_page_mlock(page); @@ -1354,6 +1363,8 @@ void page_remove_rmap(struct page *page, * Leaving it set also helps swapoff to reinstate ptes * faster for those pages still in swapcache. */ +out: + unlock_page_memcg(page); } /* --- a/mm/swapfile.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/swapfile.c @@ -1920,11 +1920,11 @@ static int unuse_pte(struct vm_area_stru 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); --- a/mm/userfaultfd.c~mm-memcontrol-switch-to-native-nr_anon_mapped-counter +++ a/mm/userfaultfd.c @@ -123,8 +123,8 @@ static int mcopy_atomic_pte(struct mm_st goto out_release_uncharge_unlock; inc_mm_counter(dst_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, dst_vma, dst_addr, false); mem_cgroup_commit_charge(page, memcg, false); + page_add_new_anon_rmap(page, dst_vma, dst_addr, false); lru_cache_add_active_or_unevictable(page, dst_vma); set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); _
