diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 74 | ||||
| -rw-r--r-- | mm/page_counter.c | 23 |
2 files changed, 5 insertions, 92 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f69da2ac6323..0e6484ea268d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -369,7 +369,6 @@ struct mem_cgroup { /* internal only representation about the status of kmem accounting. */ enum { KMEM_ACCOUNTED_ACTIVE, /* accounted by this cgroup itself */ - KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */ }; #ifdef CONFIG_MEMCG_KMEM @@ -383,22 +382,6 @@ static bool memcg_kmem_is_active(struct mem_cgroup *memcg) return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); } -static void memcg_kmem_mark_dead(struct mem_cgroup *memcg) -{ - /* - * Our caller must use css_get() first, because memcg_uncharge_kmem() - * will call css_put() if it sees the memcg is dead. - */ - smp_wmb(); - if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags)) - set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags); -} - -static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg) -{ - return test_and_clear_bit(KMEM_ACCOUNTED_DEAD, - &memcg->kmem_account_flags); -} #endif /* Stuffs for move charges at task migration. */ @@ -2758,22 +2741,7 @@ static void memcg_uncharge_kmem(struct mem_cgroup *memcg, if (do_swap_account) page_counter_uncharge(&memcg->memsw, nr_pages); - /* Not down to 0 */ - if (page_counter_uncharge(&memcg->kmem, nr_pages)) { - css_put_many(&memcg->css, nr_pages); - return; - } - - /* - * Releases a reference taken in kmem_cgroup_css_offline in case - * this last uncharge is racing with the offlining code or it is - * outliving the memcg existence. - * - * The memory barrier imposed by test&clear is paired with the - * explicit one in memcg_kmem_mark_dead(). - */ - if (memcg_kmem_test_and_clear_dead(memcg)) - css_put(&memcg->css); + page_counter_uncharge(&memcg->kmem, nr_pages); css_put_many(&memcg->css, nr_pages); } @@ -4757,40 +4725,6 @@ static void memcg_destroy_kmem(struct mem_cgroup *memcg) { mem_cgroup_sockets_destroy(memcg); } - -static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) -{ - if (!memcg_kmem_is_active(memcg)) - return; - - /* - * kmem charges can outlive the cgroup. In the case of slab - * pages, for instance, a page contain objects from various - * processes. As we prevent from taking a reference for every - * such allocation we have to be careful when doing uncharge - * (see memcg_uncharge_kmem) and here during offlining. - * - * The idea is that that only the _last_ uncharge which sees - * the dead memcg will drop the last reference. An additional - * reference is taken here before the group is marked dead - * which is then paired with css_put during uncharge resp. here. - * - * Although this might sound strange as this path is called from - * css_offline() when the referencemight have dropped down to 0 and - * shouldn't be incremented anymore (css_tryget_online() would - * fail) we do not have other options because of the kmem - * allocations lifetime. - */ - css_get(&memcg->css); - - memcg_kmem_mark_dead(memcg); - - if (page_counter_read(&memcg->kmem)) - return; - - if (memcg_kmem_test_and_clear_dead(memcg)) - css_put(&memcg->css); -} #else static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) { @@ -4800,10 +4734,6 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) static void memcg_destroy_kmem(struct mem_cgroup *memcg) { } - -static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) -{ -} #endif /* @@ -5407,8 +5337,6 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) } spin_unlock(&memcg->event_list_lock); - kmem_cgroup_css_offline(memcg); - /* * This requires that offlining is serialized. Right now that is * guaranteed because css_killed_work_fn() holds the cgroup_mutex. diff --git a/mm/page_counter.c b/mm/page_counter.c index f0cbc0825426..a009574fbba9 100644 --- a/mm/page_counter.c +++ b/mm/page_counter.c @@ -16,19 +16,14 @@ * page_counter_cancel - take pages out of the local counter * @counter: counter * @nr_pages: number of pages to cancel - * - * Returns whether there are remaining pages in the counter. */ -int page_counter_cancel(struct page_counter *counter, unsigned long nr_pages) +void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages) { long new; new = atomic_long_sub_return(nr_pages, &counter->count); - /* More uncharges than charges? */ WARN_ON_ONCE(new < 0); - - return new > 0; } /** @@ -117,23 +112,13 @@ failed: * page_counter_uncharge - hierarchically uncharge pages * @counter: counter * @nr_pages: number of pages to uncharge - * - * Returns whether there are remaining charges in @counter. */ -int page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages) +void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages) { struct page_counter *c; - int ret = 1; - for (c = counter; c; c = c->parent) { - int remainder; - - remainder = page_counter_cancel(c, nr_pages); - if (c == counter && !remainder) - ret = 0; - } - - return ret; + for (c = counter; c; c = c->parent) + page_counter_cancel(c, nr_pages); } /** |