diff options
| -rw-r--r-- | mm/memcontrol.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index bc70254558fa..f96ccc90fa66 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -547,6 +547,11 @@ static void disarm_kmem_keys(struct mem_cgroup *memcg) { if (memcg_kmem_is_active(memcg)) static_key_slow_dec(&memcg_kmem_enabled_key); + /* + * This check can't live in kmem destruction function, + * since the charges will outlive the cgroup + */ + WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0); } #else static void disarm_kmem_keys(struct mem_cgroup *memcg) @@ -4025,6 +4030,7 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg, static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) { int node, zid; + u64 usage; do { /* This is for making all *used* pages to be on LRU. */ @@ -4045,13 +4051,20 @@ static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) cond_resched(); /* + * Kernel memory may not necessarily be trackable to a specific + * process. So they are not migrated, and therefore we can't + * expect their value to drop to 0 here. + * Having res filled up with kmem only is enough. + * * This is a safety check because mem_cgroup_force_empty_list * could have raced with mem_cgroup_replace_page_cache callers * so the lru seemed empty but the page could have been added * right after the check. RES_USAGE should be safe as we always * charge before adding to the LRU. */ - } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0); + usage = res_counter_read_u64(&memcg->res, RES_USAGE) - + res_counter_read_u64(&memcg->kmem, RES_USAGE); + } while (usage > 0); } /* |