[v2 PATCH 7/9] mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers

Yang Shi
2020-12-14T22:37:59Z

Now nr_deferred is available on per memcg level for memcg aware shrinkers, so don't need
allocate shrinker->nr_deferred for such shrinkers anymore.

Signed-off-by: Yang Shi <shy828301@gmail.com>
---
mm/vmscan.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bce8cf44eca2..8d5bfd818acd 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -420,7 +420,15 @@ unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone
*/
int prealloc_shrinker(struct shrinker *shrinker)
{
- unsigned int size = sizeof(*shrinker->nr_deferred);
+ unsigned int size;
+
+ if (is_deferred_memcg_aware(shrinker)) {
+ if (prealloc_memcg_shrinker(shrinker))
+ return -ENOMEM;
+ return 0;
+ }
+
+ size = sizeof(*shrinker->nr_deferred);

if (shrinker->flags & SHRINKER_NUMA_AWARE)
size *= nr_node_ids;
@@ -429,26 +437,18 @@ int prealloc_shrinker(struct shrinker *shrinker)
if (!shrinker->nr_deferred)
return -ENOMEM;

- if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
- if (prealloc_memcg_shrinker(shrinker))
- goto free_deferred;
- }
-
return 0;
-
-free_deferred:
- kfree(shrinker->nr_deferred);
- shrinker->nr_deferred = NULL;
- return -ENOMEM;
}

void free_prealloced_shrinker(struct shrinker *shrinker)
{
- if (!shrinker->nr_deferred)
+ if (is_deferred_memcg_aware(shrinker)) {
+ unregister_memcg_shrinker(shrinker);
return;
+ }

- if (shrinker->flags & SHRINKER_MEMCG_AWARE)
- unregister_memcg_shrinker(shrinker);
+ if (!shrinker->nr_deferred)
+ return;

kfree(shrinker->nr_deferred);
shrinker->nr_deferred = NULL;
--
2.26.2