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.
Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
---
mm/vmscan.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d3f3701dfcd2..40e7751ef961 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -185,8 +185,7 @@ static LIST_HEAD(shrinker_list);
static DECLARE_RWSEM(shrinker_rwsem);
#ifdef CONFIG_MEMCG
-
-static int memcg_shrinker_map_size;
+static int shrinker_nr_max;
static void free_shrinker_map_rcu(struct rcu_head *head)
{
@@ -248,7 +247,7 @@ int alloc_shrinker_maps(struct mem_cgroup *memcg)
return 0;
down_write(&shrinker_rwsem);
- size = memcg_shrinker_map_size;
+ size = (shrinker_nr_max / BITS_PER_LONG + 1) * sizeof(unsigned long);
for_each_node(nid) {
map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid);
if (!map) {
@@ -266,10 +265,11 @@ 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 = (new_nr_max / BITS_PER_LONG + 1) * sizeof(unsigned long);
+ old_size = (shrinker_nr_max / BITS_PER_LONG + 1) * sizeof(unsigned long);
if (size <= old_size)
return 0;
@@ -286,9 +286,10 @@ static int expand_shrinker_maps(int new_id)
goto out;
}
} 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;
}
@@ -321,7 +322,6 @@ 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)
{
@@ -338,8 +338,6 @@ 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;
--
2.26.2
