From: Yang Shi <shy828301@xxxxxxxxx> Subject: mm: memcontrol: reparent nr_deferred when memcg offline Now shrinker's nr_deferred is per memcg for memcg aware shrinkers, add to parent's corresponding nr_deferred when memcg offline. Link: https://lkml.kernel.org/r/20210311190845.9708-13-shy828301@xxxxxxxxx Signed-off-by: Yang Shi <shy828301@xxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 1 + mm/vmscan.c | 24 ++++++++++++++++++++++++ 3 files changed, 26 insertions(+) --- a/include/linux/memcontrol.h~mm-memcontrol-reparent-nr_deferred-when-memcg-offline +++ a/include/linux/memcontrol.h @@ -1614,6 +1614,7 @@ static inline bool mem_cgroup_under_sock int alloc_shrinker_info(struct mem_cgroup *memcg); void free_shrinker_info(struct mem_cgroup *memcg); void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id); +void reparent_shrinker_deferred(struct mem_cgroup *memcg); #else #define mem_cgroup_sockets_enabled 0 static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; --- a/mm/memcontrol.c~mm-memcontrol-reparent-nr_deferred-when-memcg-offline +++ a/mm/memcontrol.c @@ -5154,6 +5154,7 @@ static void mem_cgroup_css_offline(struc page_counter_set_low(&memcg->memory, 0); memcg_offline_kmem(memcg); + reparent_shrinker_deferred(memcg); wb_memcg_offline(memcg); drain_all_stock(memcg); --- a/mm/vmscan.c~mm-memcontrol-reparent-nr_deferred-when-memcg-offline +++ a/mm/vmscan.c @@ -397,6 +397,30 @@ static long add_nr_deferred_memcg(long n return atomic_long_add_return(nr, &info->nr_deferred[shrinker->id]); } +void reparent_shrinker_deferred(struct mem_cgroup *memcg) +{ + int i, nid; + long nr; + struct mem_cgroup *parent; + struct shrinker_info *child_info, *parent_info; + + parent = parent_mem_cgroup(memcg); + if (!parent) + parent = root_mem_cgroup; + + /* Prevent from concurrent shrinker_info expand */ + down_read(&shrinker_rwsem); + for_each_node(nid) { + child_info = shrinker_info_protected(memcg, nid); + parent_info = shrinker_info_protected(parent, nid); + for (i = 0; i < shrinker_nr_max; i++) { + nr = atomic_long_read(&child_info->nr_deferred[i]); + atomic_long_add(nr, &parent_info->nr_deferred[i]); + } + } + up_read(&shrinker_rwsem); +} + static bool cgroup_reclaim(struct scan_control *sc) { return sc->target_mem_cgroup; _
