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 <[email protected]> --- mm/vmscan.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index d3f3701dfcd2..847369c19775 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) { @@ -266,12 +265,13 @@ 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 = (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; + goto out; if (!root_mem_cgroup) goto out; @@ -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
