diff options
| -rw-r--r-- | mm/memcontrol.c | 53 |
1 files changed, 47 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d0e57a3cda18..58a08fc7414a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -230,10 +230,30 @@ struct mem_cgroup { * the counter to account for memory usage */ struct res_counter res; - /* - * the counter to account for mem+swap usage. - */ - struct res_counter memsw; + + union { + /* + * the counter to account for mem+swap usage. + */ + struct res_counter memsw; + + /* + * rcu_freeing is used only when freeing struct mem_cgroup, + * so put it into a union to avoid wasting more memory. + * It must be disjoint from the css field. It could be + * in a union with the res field, but res plays a much + * larger part in mem_cgroup life than memsw, and might + * be of interest, even at time of free, when debugging. + * So share rcu_head with the less interesting memsw. + */ + struct rcu_head rcu_freeing; + /* + * But when using vfree(), that cannot be done at + * interrupt time, so we must then queue the work. + */ + struct work_struct work_freeing; + }; + /* * Per cgroup active and inactive list, similar to the * per zone LRU lists. @@ -4780,6 +4800,27 @@ out_free: } /* + * Helpers for freeing a vzalloc()ed mem_cgroup by RCU, + * but in process context. The work_freeing structure is overlaid + * on the rcu_freeing structure, which itself is overlaid on memsw. + */ +static void vfree_work(struct work_struct *work) +{ + struct mem_cgroup *memcg; + + memcg = container_of(work, struct mem_cgroup, work_freeing); + vfree(memcg); +} +static void vfree_rcu(struct rcu_head *rcu_head) +{ + struct mem_cgroup *memcg; + + memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); + INIT_WORK(&memcg->work_freeing, vfree_work); + schedule_work(&memcg->work_freeing); +} + +/* * At destroying mem_cgroup, references from swap_cgroup can remain. * (scanning all at force_empty is too costly...) * @@ -4802,9 +4843,9 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) free_percpu(memcg->stat); if (sizeof(struct mem_cgroup) < PAGE_SIZE) - kfree(memcg); + kfree_rcu(memcg, rcu_freeing); else - vfree(memcg); + call_rcu(&memcg->rcu_freeing, vfree_rcu); } static void mem_cgroup_get(struct mem_cgroup *memcg) |