Commit a2fb1261 authored by Yang Shi's avatar Yang Shi Committed by Linus Torvalds
Browse files

mm: vmscan: remove memcg_shrinker_map_size 

Both memcg_shrinker_map_size and shrinker_nr_max is maintained, but
actually the map size can be calculated via shrinker_nr_max, so it seems
unnecessary to keep both.  Remove memcg_shrinker_map_size since
shrinker_nr_max is also used by iterating the bit map.

Link: https://lkml.kernel.org/r/20210311190845.9708-5-shy828301@gmail.com


Signed-off-by: default avatarYang Shi <shy828301@gmail.com>
Acked-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarShakeel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d27cf2aa

mm/vmscan.c

+11 −9
Original line number Diff line number Diff line
@@ -185,8 +185,12 @@ static LIST_HEAD(shrinker_list); 
static DECLARE_RWSEM(shrinker_rwsem);



#ifdef CONFIG_MEMCG

static int shrinker_nr_max;



static int memcg_shrinker_map_size;

static inline int shrinker_map_size(int nr_items)

{

	return (DIV_ROUND_UP(nr_items, BITS_PER_LONG) * sizeof(unsigned long));

}



static void free_shrinker_map_rcu(struct rcu_head *head)

{
@@ -248,7 +252,7 @@ int alloc_shrinker_maps(struct mem_cgroup *memcg) 
		return 0;



	down_write(&shrinker_rwsem);

	size = memcg_shrinker_map_size;

	size = shrinker_map_size(shrinker_nr_max);

	for_each_node(nid) {

		map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid);

		if (!map) {
@@ -266,12 +270,13 @@ int alloc_shrinker_maps(struct mem_cgroup *memcg) 
static int expand_shrinker_maps(int new_id)

{

	int size, old_size, ret = 0;

	int new_nr_max = new_id + 1;

	struct mem_cgroup *memcg;



	size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long);

	old_size = memcg_shrinker_map_size;

	size = shrinker_map_size(new_nr_max);

	old_size = shrinker_map_size(shrinker_nr_max);

	if (size <= old_size)

		return 0;

		goto out;



	if (!root_mem_cgroup)

		goto out;
@@ -290,7 +295,7 @@ static int expand_shrinker_maps(int new_id) 
	} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);

out:

	if (!ret)

		memcg_shrinker_map_size = size;

		shrinker_nr_max = new_nr_max;



	return ret;

}
@@ -323,7 +328,6 @@ void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) 
#define SHRINKER_REGISTERING ((struct shrinker *)~0UL)



static DEFINE_IDR(shrinker_idr);

static int shrinker_nr_max;



static int prealloc_memcg_shrinker(struct shrinker *shrinker)

{
@@ -340,8 +344,6 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker) 
			idr_remove(&shrinker_idr, id);

			goto unlock;

		}



		shrinker_nr_max = id + 1;

	}

	shrinker->id = id;

	ret = 0;