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authorYang Shi <shy828301@gmail.com>2021-05-05 04:36:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-05 21:27:23 +0300
commit476b30a0949aec865dcc64d4c14f621b1a8afd12 (patch)
tree2dfa31fc16456d7a3d9b005c4136da6ca860dd72 /mm/vmscan.c
parent86750830468506dc27fa99c644534a7189be7975 (diff)
downloadlinux-476b30a0949aec865dcc64d4c14f621b1a8afd12.tar.xz
mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers
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. The prealloc_memcg_shrinker() would return -ENOSYS if !CONFIG_MEMCG or memcg is disabled by kernel command line, then shrinker's SHRINKER_MEMCG_AWARE flag would be cleared. This makes the implementation of this patch simpler. Link: https://lkml.kernel.org/r/20210311190845.9708-12-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-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>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 19b134d985c5..9617c5ff3e98 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -346,6 +346,9 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker)
{
int id, ret = -ENOMEM;
+ if (mem_cgroup_disabled())
+ return -ENOSYS;
+
down_write(&shrinker_rwsem);
/* This may call shrinker, so it must use down_read_trylock() */
id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
@@ -425,7 +428,7 @@ static bool writeback_throttling_sane(struct scan_control *sc)
#else
static int prealloc_memcg_shrinker(struct shrinker *shrinker)
{
- return 0;
+ return -ENOSYS;
}
static void unregister_memcg_shrinker(struct shrinker *shrinker)
@@ -537,8 +540,18 @@ static unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru,
*/
int prealloc_shrinker(struct shrinker *shrinker)
{
- unsigned int size = sizeof(*shrinker->nr_deferred);
+ unsigned int size;
+ int err;
+
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
+ err = prealloc_memcg_shrinker(shrinker);
+ if (err != -ENOSYS)
+ return err;
+ shrinker->flags &= ~SHRINKER_MEMCG_AWARE;
+ }
+
+ size = sizeof(*shrinker->nr_deferred);
if (shrinker->flags & SHRINKER_NUMA_AWARE)
size *= nr_node_ids;
@@ -546,28 +559,16 @@ 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)
- return;
-
if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
down_write(&shrinker_rwsem);
unregister_memcg_shrinker(shrinker);
up_write(&shrinker_rwsem);
+ return;
}
kfree(shrinker->nr_deferred);