Re: [v6 PATCH 05/11] mm: memcontrol: rename shrinker_map to shrinker_info

From: Kirill Tkhai
Date: Thu Feb 04 2021 - 03:05:30 EST


On 03.02.2021 20:20, Yang Shi wrote:
> The following patch is going to add nr_deferred into shrinker_map, the change will
> make shrinker_map not only include map anymore, so rename it to "memcg_shrinker_info".
> And this should make the patch adding nr_deferred cleaner and readable and make
> review easier. Also remove the "memcg_" prefix.
>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>

Acked-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>

> ---
> include/linux/memcontrol.h | 8 ++---
> mm/memcontrol.c | 6 ++--
> mm/vmscan.c | 62 +++++++++++++++++++-------------------
> 3 files changed, 38 insertions(+), 38 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 1739f17e0939..4c9253896e25 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -96,7 +96,7 @@ struct lruvec_stat {
> * Bitmap of shrinker::id corresponding to memcg-aware shrinkers,
> * which have elements charged to this memcg.
> */
> -struct memcg_shrinker_map {
> +struct shrinker_info {
> struct rcu_head rcu;
> unsigned long map[];
> };
> @@ -118,7 +118,7 @@ struct mem_cgroup_per_node {
>
> struct mem_cgroup_reclaim_iter iter;
>
> - struct memcg_shrinker_map __rcu *shrinker_map;
> + struct shrinker_info __rcu *shrinker_info;
>
> struct rb_node tree_node; /* RB tree node */
> unsigned long usage_in_excess;/* Set to the value by which */
> @@ -1581,8 +1581,8 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
> return false;
> }
>
> -int alloc_shrinker_maps(struct mem_cgroup *memcg);
> -void free_shrinker_maps(struct mem_cgroup *memcg);
> +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);
> #else
> #define mem_cgroup_sockets_enabled 0
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f5c9a0d2160b..f64ad0d044d9 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5246,11 +5246,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
> struct mem_cgroup *memcg = mem_cgroup_from_css(css);
>
> /*
> - * A memcg must be visible for expand_shrinker_maps()
> + * A memcg must be visible for expand_shrinker_info()
> * by the time the maps are allocated. So, we allocate maps
> * here, when for_each_mem_cgroup() can't skip it.
> */
> - if (alloc_shrinker_maps(memcg)) {
> + if (alloc_shrinker_info(memcg)) {
> mem_cgroup_id_remove(memcg);
> return -ENOMEM;
> }
> @@ -5314,7 +5314,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> vmpressure_cleanup(&memcg->vmpressure);
> cancel_work_sync(&memcg->high_work);
> mem_cgroup_remove_from_trees(memcg);
> - free_shrinker_maps(memcg);
> + free_shrinker_info(memcg);
> memcg_free_kmem(memcg);
> mem_cgroup_free(memcg);
> }
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 641077b09e5d..9436f9246d32 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -190,20 +190,20 @@ static int shrinker_nr_max;
> #define NR_MAX_TO_SHR_MAP_SIZE(nr_max) \
> (DIV_ROUND_UP(nr_max, BITS_PER_LONG) * sizeof(unsigned long))
>
> -static void free_shrinker_map_rcu(struct rcu_head *head)
> +static void free_shrinker_info_rcu(struct rcu_head *head)
> {
> - kvfree(container_of(head, struct memcg_shrinker_map, rcu));
> + kvfree(container_of(head, struct shrinker_info, rcu));
> }
>
> -static int expand_one_shrinker_map(struct mem_cgroup *memcg,
> +static int expand_one_shrinker_info(struct mem_cgroup *memcg,
> int size, int old_size)
> {
> - struct memcg_shrinker_map *new, *old;
> + struct shrinker_info *new, *old;
> int nid;
>
> for_each_node(nid) {
> old = rcu_dereference_protected(
> - mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true);
> + mem_cgroup_nodeinfo(memcg, nid)->shrinker_info, true);
> /* Not yet online memcg */
> if (!old)
> return 0;
> @@ -216,17 +216,17 @@ static int expand_one_shrinker_map(struct mem_cgroup *memcg,
> 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, free_shrinker_map_rcu);
> + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, new);
> + call_rcu(&old->rcu, free_shrinker_info_rcu);
> }
>
> return 0;
> }
>
> -void free_shrinker_maps(struct mem_cgroup *memcg)
> +void free_shrinker_info(struct mem_cgroup *memcg)
> {
> struct mem_cgroup_per_node *pn;
> - struct memcg_shrinker_map *map;
> + struct shrinker_info *info;
> int nid;
>
> if (mem_cgroup_is_root(memcg))
> @@ -234,15 +234,15 @@ void free_shrinker_maps(struct mem_cgroup *memcg)
>
> for_each_node(nid) {
> pn = mem_cgroup_nodeinfo(memcg, nid);
> - map = rcu_dereference_protected(pn->shrinker_map, true);
> - kvfree(map);
> - rcu_assign_pointer(pn->shrinker_map, NULL);
> + info = rcu_dereference_protected(pn->shrinker_info, true);
> + kvfree(info);
> + rcu_assign_pointer(pn->shrinker_info, NULL);
> }
> }
>
> -int alloc_shrinker_maps(struct mem_cgroup *memcg)
> +int alloc_shrinker_info(struct mem_cgroup *memcg)
> {
> - struct memcg_shrinker_map *map;
> + struct shrinker_info *info;
> int nid, size, ret = 0;
>
> if (mem_cgroup_is_root(memcg))
> @@ -251,20 +251,20 @@ int alloc_shrinker_maps(struct mem_cgroup *memcg)
> down_write(&shrinker_rwsem);
> size = NR_MAX_TO_SHR_MAP_SIZE(shrinker_nr_max);
> for_each_node(nid) {
> - map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid);
> - if (!map) {
> - free_shrinker_maps(memcg);
> + info = kvzalloc_node(sizeof(*info) + size, GFP_KERNEL, nid);
> + if (!info) {
> + free_shrinker_info(memcg);
> ret = -ENOMEM;
> break;
> }
> - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map);
> + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
> }
> up_write(&shrinker_rwsem);
>
> return ret;
> }
>
> -static int expand_shrinker_maps(int new_id)
> +static int expand_shrinker_info(int new_id)
> {
> int size, old_size, ret = 0;
> int new_nr_max = new_id + 1;
> @@ -282,7 +282,7 @@ static int expand_shrinker_maps(int new_id)
> do {
> if (mem_cgroup_is_root(memcg))
> continue;
> - ret = expand_one_shrinker_map(memcg, size, old_size);
> + ret = expand_one_shrinker_info(memcg, size, old_size);
> if (ret) {
> mem_cgroup_iter_break(NULL, memcg);
> goto out;
> @@ -298,13 +298,13 @@ static int expand_shrinker_maps(int new_id)
> void 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;
> + struct shrinker_info *info;
>
> rcu_read_lock();
> - map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map);
> + info = rcu_dereference(memcg->nodeinfo[nid]->shrinker_info);
> /* Pairs with smp mb in shrink_slab() */
> smp_mb__before_atomic();
> - set_bit(shrinker_id, map->map);
> + set_bit(shrinker_id, info->map);
> rcu_read_unlock();
> }
> }
> @@ -335,7 +335,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker)
> goto unlock;
>
> if (id >= shrinker_nr_max) {
> - if (expand_shrinker_maps(id)) {
> + if (expand_shrinker_info(id)) {
> idr_remove(&shrinker_idr, id);
> goto unlock;
> }
> @@ -664,7 +664,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
> static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
> struct mem_cgroup *memcg, int priority)
> {
> - struct memcg_shrinker_map *map;
> + struct shrinker_info *info;
> unsigned long ret, freed = 0;
> int i;
>
> @@ -674,12 +674,12 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
> if (!down_read_trylock(&shrinker_rwsem))
> return 0;
>
> - map = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_map,
> - true);
> - if (unlikely(!map))
> + info = rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info,
> + true);
> + if (unlikely(!info))
> goto unlock;
>
> - for_each_set_bit(i, map->map, shrinker_nr_max) {
> + for_each_set_bit(i, info->map, shrinker_nr_max) {
> struct shrink_control sc = {
> .gfp_mask = gfp_mask,
> .nid = nid,
> @@ -690,7 +690,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
> shrinker = idr_find(&shrinker_idr, i);
> if (unlikely(!shrinker || shrinker == SHRINKER_REGISTERING)) {
> if (!shrinker)
> - clear_bit(i, map->map);
> + clear_bit(i, info->map);
> continue;
> }
>
> @@ -701,7 +701,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
>
> ret = do_shrink_slab(&sc, shrinker, priority);
> if (ret == SHRINK_EMPTY) {
> - clear_bit(i, map->map);
> + clear_bit(i, info->map);
> /*
> * After the shrinker reported that it had no objects to
> * free, but before we cleared the corresponding bit in
>