From: Qi Zheng To resolve the dying memcg issue, we need to reparent LRU folios of child memcg to its parent memcg. The following counts are all non-hierarchical and need to be reparented to prevent the counts of parent memcg overflow. 1. memcg->vmstats->state_local[i] 2. pn->lruvec_stats->state_local[i] This commit implements the specific function, which will be used during the reparenting process. Signed-off-by: Qi Zheng --- include/linux/memcontrol.h | 4 +++ mm/memcontrol-v1.c | 16 +++++++++++ mm/memcontrol-v1.h | 3 ++ mm/memcontrol.c | 56 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 79 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 26c3c0e375f58..f84a23f13ffb4 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -963,12 +963,16 @@ static inline void mod_memcg_page_state(struct page *page, unsigned long memcg_events(struct mem_cgroup *memcg, int event); unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx); +void reparent_memcg_state_local(struct mem_cgroup *memcg, + struct mem_cgroup *parent, int idx); unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item); bool memcg_stat_item_valid(int idx); bool memcg_vm_event_item_valid(enum vm_event_item idx); unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx); unsigned long lruvec_page_state_local(struct lruvec *lruvec, enum node_stat_item idx); +void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg, + struct mem_cgroup *parent, int idx); void mem_cgroup_flush_stats(struct mem_cgroup *memcg); void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg); diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c index f0ef650d2317b..800606135e7ba 100644 --- a/mm/memcontrol-v1.c +++ b/mm/memcontrol-v1.c @@ -1898,6 +1898,22 @@ static const unsigned int memcg1_events[] = { PGMAJFAULT, }; +void reparent_memcg1_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) + reparent_memcg_state_local(memcg, parent, memcg1_stats[i]); +} + +void reparent_memcg1_lruvec_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) + reparent_memcg_lruvec_state_local(memcg, parent, memcg1_stats[i]); +} + void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) { unsigned long memory, memsw; diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h index eb3c3c1056574..45528195d3578 100644 --- a/mm/memcontrol-v1.h +++ b/mm/memcontrol-v1.h @@ -41,6 +41,7 @@ static inline bool do_memsw_account(void) unsigned long memcg_events_local(struct mem_cgroup *memcg, int event); unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx); +void mod_memcg_page_state_local(struct mem_cgroup *memcg, int idx, unsigned long val); unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item); bool memcg1_alloc_events(struct mem_cgroup *memcg); void memcg1_free_events(struct mem_cgroup *memcg); @@ -73,6 +74,8 @@ void memcg1_uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, unsigned long nr_memory, int nid); void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s); +void reparent_memcg1_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent); +void reparent_memcg1_lruvec_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent); void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages); static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 70583394f421f..7aa32b97c9f17 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -225,6 +225,28 @@ static inline struct obj_cgroup *__memcg_reparent_objcgs(struct mem_cgroup *memc return objcg; } +#ifdef CONFIG_MEMCG_V1 +static void __mem_cgroup_flush_stats(struct mem_cgroup *memcg, bool force); + +static inline void reparent_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return; + + synchronize_rcu(); + + __mem_cgroup_flush_stats(memcg, true); + + /* The following counts are all non-hierarchical and need to be reparented. */ + reparent_memcg1_state_local(memcg, parent); + reparent_memcg1_lruvec_state_local(memcg, parent); +} +#else +static inline void reparent_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent) +{ +} +#endif + static inline void reparent_locks(struct mem_cgroup *memcg, struct mem_cgroup *parent) { spin_lock_irq(&objcg_lock); @@ -458,6 +480,28 @@ unsigned long lruvec_page_state_local(struct lruvec *lruvec, return x; } +void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg, + struct mem_cgroup *parent, int idx) +{ + int i = memcg_stats_index(idx); + int nid; + + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return; + + for_each_node(nid) { + struct lruvec *child_lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); + struct lruvec *parent_lruvec = mem_cgroup_lruvec(parent, NODE_DATA(nid)); + struct mem_cgroup_per_node *parent_pn; + unsigned long value = lruvec_page_state_local(child_lruvec, idx); + + parent_pn = container_of(parent_lruvec, struct mem_cgroup_per_node, lruvec); + + WRITE_ONCE(parent_pn->lruvec_stats->state_local[i], + parent_pn->lruvec_stats->state_local[i] + value); + } +} + /* Subset of vm_event_item to report for memcg event stats */ static const unsigned int memcg_vm_event_stat[] = { #ifdef CONFIG_MEMCG_V1 @@ -757,6 +801,18 @@ unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) #endif return x; } + +void reparent_memcg_state_local(struct mem_cgroup *memcg, + struct mem_cgroup *parent, int idx) +{ + int i = memcg_stats_index(idx); + unsigned long value = memcg_page_state_local(memcg, idx); + + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return; + + WRITE_ONCE(parent->vmstats->state_local[i], parent->vmstats->state_local[i] + value); +} #endif static void mod_memcg_lruvec_state(struct lruvec *lruvec, -- 2.20.1