mm: memcontrol: switch to native NR_ANON_THPS counter

With rmap memcg locking already in place for NR_ANON_MAPPED, it's just a
small step to remove the MEMCG_RSS_HUGE wart and switch memcg to the
native NR_ANON_THPS accounting sites.

[hannes@cmpxchg.org: fixes]
Link: http://lkml.kernel.org/r/20200512121750.GA397968@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>	[build-tested]
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/20200508183105.225460-12-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index acacc30..63a31a6 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/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_HUGE = NR_VM_NODE_STAT_ITEMS,
-       MEMCG_SWAP,
+       MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
        MEMCG_SOCK,
        /* XXX: why are these zone and not node counters? */
        MEMCG_KERNEL_STACK_KB,

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 2caf249..1fe980d 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2159,15 +2159,17 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
                        atomic_inc(&page[i]._mapcount);
        }
 
+       lock_page_memcg(page);
        if (atomic_add_negative(-1, compound_mapcount_ptr(page))) {
                /* Last compound_mapcount is gone. */
-               __dec_node_page_state(page, NR_ANON_THPS);
+               __dec_lruvec_page_state(page, NR_ANON_THPS);
                if (TestClearPageDoubleMap(page)) {
                        /* No need in mapcount reference anymore */
                        for (i = 0; i < HPAGE_PMD_NR; i++)
                                atomic_dec(&page[i]._mapcount);
                }
        }
+       unlock_page_memcg(page);
 
        smp_wmb(); /* make pte visible before pmd */
        pmd_populate(mm, pmd, pgtable);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b801253..17587ea 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -836,11 +836,6 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
                                         struct page *page,
                                         int nr_pages)
 {
-       if (abs(nr_pages) > 1) {
-               VM_BUG_ON_PAGE(!PageTransHuge(page), page);
-               __mod_memcg_state(memcg, MEMCG_RSS_HUGE, nr_pages);
-       }
-
        /* pagein of a big page is an event. So, ignore page size */
        if (nr_pages > 0)
                __count_memcg_events(memcg, PGPGIN, 1);
@@ -1406,15 +1401,11 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
                       (u64)memcg_page_state(memcg, NR_WRITEBACK) *
                       PAGE_SIZE);
 
-       /*
-        * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
-        * with the NR_ANON_THP vm counter, but right now it's a pain in the
-        * arse because it requires migrating the work out of rmap to a place
-        * where the page->mem_cgroup is set up and stable.
-        */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
        seq_buf_printf(&s, "anon_thp %llu\n",
-                      (u64)memcg_page_state(memcg, MEMCG_RSS_HUGE) *
-                      PAGE_SIZE);
+                      (u64)memcg_page_state(memcg, NR_ANON_THPS) *
+                      HPAGE_PMD_SIZE);
+#endif
 
        for (i = 0; i < NR_LRU_LISTS; i++)
                seq_buf_printf(&s, "%s %llu\n", lru_list_name(i),
@@ -3061,8 +3052,6 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 
        for (i = 1; i < HPAGE_PMD_NR; i++)
                head[i].mem_cgroup = head->mem_cgroup;
-
-       __mod_memcg_state(head->mem_cgroup, MEMCG_RSS_HUGE, -HPAGE_PMD_NR);
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
@@ -3818,7 +3807,9 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v)
 static const unsigned int memcg1_stats[] = {
        NR_FILE_PAGES,
        NR_ANON_MAPPED,
-       MEMCG_RSS_HUGE,
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       NR_ANON_THPS,
+#endif
        NR_SHMEM,
        NR_FILE_MAPPED,
        NR_FILE_DIRTY,
@@ -3829,7 +3820,9 @@ static const unsigned int memcg1_stats[] = {
 static const char *const memcg1_stat_names[] = {
        "cache",
        "rss",
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
        "rss_huge",
+#endif
        "shmem",
        "mapped_file",
        "dirty",
@@ -3855,11 +3848,16 @@ static int memcg_stat_show(struct seq_file *m, void *v)
        BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
 
        for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
+               unsigned long nr;
+
                if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
                        continue;
-               seq_printf(m, "%s %lu\n", memcg1_stat_names[i],
-                          memcg_page_state_local(memcg, memcg1_stats[i]) *
-                          PAGE_SIZE);
+               nr = memcg_page_state_local(memcg, memcg1_stats[i]);
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+               if (memcg1_stats[i] == NR_ANON_THPS)
+                       nr *= HPAGE_PMD_NR;
+#endif
+               seq_printf(m, "%s %lu\n", memcg1_stat_names[i], nr * PAGE_SIZE);
        }
 
        for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
@@ -5452,6 +5450,13 @@ static int mem_cgroup_move_account(struct page *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);
+                       if (PageTransHuge(page)) {
+                               __mod_lruvec_state(from_vec, NR_ANON_THPS,
+                                                  -nr_pages);
+                               __mod_lruvec_state(to_vec, NR_ANON_THPS,
+                                                  nr_pages);
+                       }
+
                }
        } else {
                __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
@@ -6671,7 +6676,6 @@ struct uncharge_gather {
        unsigned long nr_pages;
        unsigned long pgpgout;
        unsigned long nr_kmem;
-       unsigned long nr_huge;
        struct page *dummy_page;
 };
 
@@ -6694,7 +6698,6 @@ static void uncharge_batch(const struct uncharge_gather *ug)
        }
 
        local_irq_save(flags);
-       __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);
        memcg_check_events(ug->memcg, ug->dummy_page);
@@ -6731,8 +6734,6 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
        ug->nr_pages += nr_pages;
 
        if (!PageKmemcg(page)) {
-               if (PageTransHuge(page))
-                       ug->nr_huge += nr_pages;
                ug->pgpgout++;
        } else {
                ug->nr_kmem += nr_pages;

diff --git a/mm/rmap.c b/mm/rmap.c
index 150513d..ad4a0fd 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1138,7 +1138,7 @@ void do_page_add_anon_rmap(struct page *page,
                 * disabled.
                 */
                if (compound)
-                       __inc_node_page_state(page, NR_ANON_THPS);
+                       __inc_lruvec_page_state(page, NR_ANON_THPS);
                __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr);
        }
 
@@ -1180,7 +1180,7 @@ void page_add_new_anon_rmap(struct page *page,
                if (hpage_pincount_available(page))
                        atomic_set(compound_pincount_ptr(page), 0);
 
-               __inc_node_page_state(page, NR_ANON_THPS);
+               __inc_lruvec_page_state(page, NR_ANON_THPS);
        } else {
                /* Anon THP always mapped first with PMD */
                VM_BUG_ON_PAGE(PageTransCompound(page), page);
@@ -1286,7 +1286,7 @@ static void page_remove_anon_compound_rmap(struct page *page)
        if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
                return;
 
-       __dec_node_page_state(page, NR_ANON_THPS);
+       __dec_lruvec_page_state(page, NR_ANON_THPS);
 
        if (TestClearPageDoubleMap(page)) {
                /*