mm: vmscan: consolidate shrinker_maps handling code

The shrinker map management is not purely memcg specific, it is at the
intersection between memory cgroup and shrinkers.  It's 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, and remove the
"memcg_" prefix.  There is no functional change.

Link: https://lkml.kernel.org/r/20210311190845.9708-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yang Shi 2021-05-04 18:36:11 -07:00 committed by Linus Torvalds
parent 8efb4b596d
commit 2bfd36374e
5 changed files with 142 additions and 141 deletions

View File

@ -1610,10 +1610,9 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
return false;
}
extern int memcg_expand_shrinker_maps(int new_id);
extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
int nid, int shrinker_id);
int alloc_shrinker_maps(struct mem_cgroup *memcg);
void free_shrinker_maps(struct mem_cgroup *memcg);
void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id);
#else
#define mem_cgroup_sockets_enabled 0
static inline void mem_cgroup_sk_alloc(struct sock *sk) { };
@ -1623,8 +1622,8 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
return false;
}
static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg,
int nid, int shrinker_id)
static inline void set_shrinker_bit(struct mem_cgroup *memcg,
int nid, int shrinker_id)
{
}
#endif

View File

@ -2830,8 +2830,8 @@ void deferred_split_huge_page(struct page *page)
ds_queue->split_queue_len++;
#ifdef CONFIG_MEMCG
if (memcg)
memcg_set_shrinker_bit(memcg, page_to_nid(page),
deferred_split_shrinker.id);
set_shrinker_bit(memcg, page_to_nid(page),
deferred_split_shrinker.id);
#endif
}
spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags);

View File

@ -125,8 +125,8 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
list_add_tail(item, &l->list);
/* Set shrinker bit if the first element was added */
if (!l->nr_items++)
memcg_set_shrinker_bit(memcg, nid,
lru_shrinker_id(lru));
set_shrinker_bit(memcg, nid,
lru_shrinker_id(lru));
nlru->nr_items++;
spin_unlock(&nlru->lock);
return true;
@ -540,7 +540,7 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
if (src->nr_items) {
dst->nr_items += src->nr_items;
memcg_set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
src->nr_items = 0;
}

View File

@ -400,130 +400,6 @@ 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;
struct mem_cgroup_per_node *pn;
int nid;
lockdep_assert_held(&memcg_shrinker_map_mutex);
for_each_node(nid) {
pn = memcg->nodeinfo[nid];
old = rcu_dereference_protected(pn->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(pn->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 = memcg->nodeinfo[nid];
map = rcu_dereference_protected(pn->shrinker_map, true);
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
@ -5242,11 +5118,11 @@ 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 memcg_expand_shrinker_maps()
* A memcg must be visible for expand_shrinker_maps()
* by the time the maps are allocated. So, we allocate maps
* here, when for_each_mem_cgroup() can't skip it.
*/
if (memcg_alloc_shrinker_maps(memcg)) {
if (alloc_shrinker_maps(memcg)) {
mem_cgroup_id_remove(memcg);
return -ENOMEM;
}
@ -5310,7 +5186,7 @@ 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);
memcg_free_shrinker_maps(memcg);
free_shrinker_maps(memcg);
memcg_free_kmem(memcg);
mem_cgroup_free(memcg);
}

View File

@ -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 free_shrinker_map_rcu(struct rcu_head *head)
{
kvfree(container_of(head, struct memcg_shrinker_map, rcu));
}
static int expand_one_shrinker_map(struct mem_cgroup *memcg,
int size, int old_size)
{
struct memcg_shrinker_map *new, *old;
struct mem_cgroup_per_node *pn;
int nid;
lockdep_assert_held(&memcg_shrinker_map_mutex);
for_each_node(nid) {
pn = memcg->nodeinfo[nid];
old = rcu_dereference_protected(pn->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(pn->shrinker_map, new);
call_rcu(&old->rcu, free_shrinker_map_rcu);
}
return 0;
}
void 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 = memcg->nodeinfo[nid];
map = rcu_dereference_protected(pn->shrinker_map, true);
kvfree(map);
rcu_assign_pointer(pn->shrinker_map, NULL);
}
}
int 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) {
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 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 = 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 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
@ -212,7 +338,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker)
goto unlock;
if (id >= shrinker_nr_max) {
if (memcg_expand_shrinker_maps(id)) {
if (expand_shrinker_maps(id)) {
idr_remove(&shrinker_idr, id);
goto unlock;
}
@ -590,7 +716,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
* case, we invoke the shrinker one more time and reset
* the bit if it reports that it is not empty anymore.
* The memory barrier here pairs with the barrier in
* memcg_set_shrinker_bit():
* set_shrinker_bit():
*
* list_lru_add() shrink_slab_memcg()
* list_add_tail() clear_bit()
@ -602,7 +728,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
if (ret == SHRINK_EMPTY)
ret = 0;
else
memcg_set_shrinker_bit(memcg, nid, i);
set_shrinker_bit(memcg, nid, i);
}
freed += ret;