The shrinker map management is not really memcg specific, it's just allocation and assignment of a structure, and the only memcg bit is the map is being stored in a memcg structure. So move the shrinker_maps handling code into vmscan.c for tighter integration with shrinker code. There is no functional change. Signed-off-by: Yang Shi <shy828301@xxxxxxxxx> --- include/linux/memcontrol.h | 4 +- mm/memcontrol.c | 124 ------------------------------------ mm/vmscan.c | 126 +++++++++++++++++++++++++++++++++++++ 3 files changed, 128 insertions(+), 126 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d827bd7f3bfe..d128d2842f22 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1581,8 +1581,8 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) return false; } -extern int memcg_expand_shrinker_maps(int new_id); - +extern int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg); +extern void memcg_free_shrinker_maps(struct mem_cgroup *memcg); extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id); #else diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 605f671203ef..817dde366258 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -397,130 +397,6 @@ DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); EXPORT_SYMBOL(memcg_kmem_enabled_key); #endif -static int memcg_shrinker_map_size; -static DEFINE_MUTEX(memcg_shrinker_map_mutex); - -static void memcg_free_shrinker_map_rcu(struct rcu_head *head) -{ - kvfree(container_of(head, struct memcg_shrinker_map, rcu)); -} - -static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, - int size, int old_size) -{ - struct memcg_shrinker_map *new, *old; - int nid; - - lockdep_assert_held(&memcg_shrinker_map_mutex); - - for_each_node(nid) { - old = rcu_dereference_protected( - mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); - /* Not yet online memcg */ - if (!old) - return 0; - - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); - if (!new) - return -ENOMEM; - - /* Set all old bits, clear all new bits */ - memset(new->map, (int)0xff, old_size); - memset((void *)new->map + old_size, 0, size - old_size); - - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); - call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); - } - - return 0; -} - -static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) -{ - struct mem_cgroup_per_node *pn; - struct memcg_shrinker_map *map; - int nid; - - if (mem_cgroup_is_root(memcg)) - return; - - for_each_node(nid) { - pn = mem_cgroup_nodeinfo(memcg, nid); - map = rcu_dereference_protected(pn->shrinker_map, true); - if (map) - kvfree(map); - rcu_assign_pointer(pn->shrinker_map, NULL); - } -} - -static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) -{ - struct memcg_shrinker_map *map; - int nid, size, ret = 0; - - if (mem_cgroup_is_root(memcg)) - return 0; - - mutex_lock(&memcg_shrinker_map_mutex); - size = memcg_shrinker_map_size; - for_each_node(nid) { - map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); - if (!map) { - memcg_free_shrinker_maps(memcg); - ret = -ENOMEM; - break; - } - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); - } - mutex_unlock(&memcg_shrinker_map_mutex); - - return ret; -} - -int memcg_expand_shrinker_maps(int new_id) -{ - int size, old_size, ret = 0; - struct mem_cgroup *memcg; - - size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); - old_size = memcg_shrinker_map_size; - if (size <= old_size) - return 0; - - mutex_lock(&memcg_shrinker_map_mutex); - if (!root_mem_cgroup) - goto unlock; - - for_each_mem_cgroup(memcg) { - if (mem_cgroup_is_root(memcg)) - continue; - ret = memcg_expand_one_shrinker_map(memcg, size, old_size); - if (ret) { - mem_cgroup_iter_break(NULL, memcg); - goto unlock; - } - } -unlock: - if (!ret) - memcg_shrinker_map_size = size; - mutex_unlock(&memcg_shrinker_map_mutex); - return ret; -} - -void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) -{ - if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { - struct memcg_shrinker_map *map; - - rcu_read_lock(); - map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); - /* Pairs with smp mb in shrink_slab() */ - smp_mb__before_atomic(); - set_bit(shrinker_id, map->map); - rcu_read_unlock(); - } -} - /** * mem_cgroup_css_from_page - css of the memcg associated with a page * @page: page of interest diff --git a/mm/vmscan.c b/mm/vmscan.c index cb24ef952efc..9db7b4d6d0ae 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -185,6 +185,132 @@ static LIST_HEAD(shrinker_list); static DECLARE_RWSEM(shrinker_rwsem); #ifdef CONFIG_MEMCG + +static int memcg_shrinker_map_size; +static DEFINE_MUTEX(memcg_shrinker_map_mutex); + +static void memcg_free_shrinker_map_rcu(struct rcu_head *head) +{ + kvfree(container_of(head, struct memcg_shrinker_map, rcu)); +} + +static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, + int size, int old_size) +{ + struct memcg_shrinker_map *new, *old; + int nid; + + lockdep_assert_held(&memcg_shrinker_map_mutex); + + for_each_node(nid) { + old = rcu_dereference_protected( + mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); + /* Not yet online memcg */ + if (!old) + return 0; + + new = kvmalloc(sizeof(*new) + size, GFP_KERNEL); + if (!new) + return -ENOMEM; + + /* Set all old bits, clear all new bits */ + memset(new->map, (int)0xff, old_size); + memset((void *)new->map + old_size, 0, size - old_size); + + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); + call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); + } + + return 0; +} + +void memcg_free_shrinker_maps(struct mem_cgroup *memcg) +{ + struct mem_cgroup_per_node *pn; + struct memcg_shrinker_map *map; + int nid; + + if (mem_cgroup_is_root(memcg)) + return; + + for_each_node(nid) { + pn = mem_cgroup_nodeinfo(memcg, nid); + map = rcu_dereference_protected(pn->shrinker_map, true); + if (map) + kvfree(map); + rcu_assign_pointer(pn->shrinker_map, NULL); + } +} + +int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) +{ + struct memcg_shrinker_map *map; + int nid, size, ret = 0; + + if (mem_cgroup_is_root(memcg)) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + size = memcg_shrinker_map_size; + for_each_node(nid) { + map = kvzalloc(sizeof(*map) + size, GFP_KERNEL); + if (!map) { + memcg_free_shrinker_maps(memcg); + ret = -ENOMEM; + break; + } + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); + } + mutex_unlock(&memcg_shrinker_map_mutex); + + return ret; +} + +static int memcg_expand_shrinker_maps(int new_id) +{ + int size, old_size, ret = 0; + struct mem_cgroup *memcg; + + size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); + old_size = memcg_shrinker_map_size; + if (size <= old_size) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + if (!root_mem_cgroup) + goto unlock; + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + if (mem_cgroup_is_root(memcg)) + continue; + ret = memcg_expand_one_shrinker_map(memcg, size, old_size); + if (ret) { + mem_cgroup_iter_break(NULL, memcg); + goto unlock; + } + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); +unlock: + if (!ret) + memcg_shrinker_map_size = size; + mutex_unlock(&memcg_shrinker_map_mutex); + return ret; +} + +void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) +{ + if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { + struct memcg_shrinker_map *map; + + rcu_read_lock(); + map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); + /* Pairs with smp mb in shrink_slab() */ + smp_mb__before_atomic(); + set_bit(shrinker_id, map->map); + rcu_read_unlock(); + } +} + /* * We allow subsystems to populate their shrinker-related * LRU lists before register_shrinker_prepared() is called -- 2.26.2