diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 180 |
1 files changed, 35 insertions, 145 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 85df503..ef91e85 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -296,7 +296,6 @@ struct mem_cgroup { * Should the accounting and control be hierarchical, per subtree? */ bool use_hierarchy; - unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ bool oom_lock; atomic_t under_oom; @@ -366,22 +365,11 @@ struct mem_cgroup { /* WARNING: nodeinfo must be the last member here */ }; -/* internal only representation about the status of kmem accounting. */ -enum { - KMEM_ACCOUNTED_ACTIVE, /* accounted by this cgroup itself */ -}; - #ifdef CONFIG_MEMCG_KMEM -static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) -{ - set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); -} - static bool memcg_kmem_is_active(struct mem_cgroup *memcg) { - return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); + return memcg->kmemcg_id >= 0; } - #endif /* Stuffs for move charges at task migration. */ @@ -1571,7 +1559,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, * select it. The goal is to allow it to allocate so that it may * quickly exit and free its memory. */ - if (fatal_signal_pending(current) || current->flags & PF_EXITING) { + if (fatal_signal_pending(current) || task_will_free_mem(current)) { set_thread_flag(TIF_MEMDIE); return; } @@ -1628,6 +1616,8 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, NULL, "Memory cgroup out of memory"); } +#if MAX_NUMNODES > 1 + /** * test_mem_cgroup_node_reclaimable * @memcg: the target memcg @@ -1650,7 +1640,6 @@ static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, return false; } -#if MAX_NUMNODES > 1 /* * Always updating the nodemask is not very good - even if we have an empty @@ -2646,7 +2635,6 @@ static void memcg_register_cache(struct mem_cgroup *memcg, if (!cachep) return; - css_get(&memcg->css); list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches); /* @@ -2680,40 +2668,6 @@ static void memcg_unregister_cache(struct kmem_cache *cachep) list_del(&cachep->memcg_params->list); kmem_cache_destroy(cachep); - - /* drop the reference taken in memcg_register_cache */ - css_put(&memcg->css); -} - -/* - * During the creation a new cache, we need to disable our accounting mechanism - * altogether. This is true even if we are not creating, but rather just - * enqueing new caches to be created. - * - * This is because that process will trigger allocations; some visible, like - * explicit kmallocs to auxiliary data structures, name strings and internal - * cache structures; some well concealed, like INIT_WORK() that can allocate - * objects during debug. - * - * If any allocation happens during memcg_kmem_get_cache, we will recurse back - * to it. This may not be a bounded recursion: since the first cache creation - * failed to complete (waiting on the allocation), we'll just try to create the - * cache again, failing at the same point. - * - * memcg_kmem_get_cache is prepared to abort after seeing a positive count of - * memcg_kmem_skip_account. So we enclose anything that might allocate memory - * inside the following two functions. - */ -static inline void memcg_stop_kmem_account(void) -{ - VM_BUG_ON(!current->mm); - current->memcg_kmem_skip_account++; -} - -static inline void memcg_resume_kmem_account(void) -{ - VM_BUG_ON(!current->mm); - current->memcg_kmem_skip_account--; } int __memcg_cleanup_cache_params(struct kmem_cache *s) @@ -2747,9 +2701,7 @@ static void memcg_unregister_all_caches(struct mem_cgroup *memcg) mutex_lock(&memcg_slab_mutex); list_for_each_entry_safe(params, tmp, &memcg->memcg_slab_caches, list) { cachep = memcg_params_to_cache(params); - kmem_cache_shrink(cachep); - if (atomic_read(&cachep->memcg_params->nr_pages) == 0) - memcg_unregister_cache(cachep); + memcg_unregister_cache(cachep); } mutex_unlock(&memcg_slab_mutex); } @@ -2784,10 +2736,10 @@ static void __memcg_schedule_register_cache(struct mem_cgroup *memcg, struct memcg_register_cache_work *cw; cw = kmalloc(sizeof(*cw), GFP_NOWAIT); - if (cw == NULL) { - css_put(&memcg->css); + if (!cw) return; - } + + css_get(&memcg->css); cw->memcg = memcg; cw->cachep = cachep; @@ -2810,20 +2762,16 @@ static void memcg_schedule_register_cache(struct mem_cgroup *memcg, * this point we can't allow ourselves back into memcg_kmem_get_cache, * the safest choice is to do it like this, wrapping the whole function. */ - memcg_stop_kmem_account(); + current->memcg_kmem_skip_account = 1; __memcg_schedule_register_cache(memcg, cachep); - memcg_resume_kmem_account(); + current->memcg_kmem_skip_account = 0; } int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order) { unsigned int nr_pages = 1 << order; - int res; - res = memcg_charge_kmem(cachep->memcg_params->memcg, gfp, nr_pages); - if (!res) - atomic_add(nr_pages, &cachep->memcg_params->nr_pages); - return res; + return memcg_charge_kmem(cachep->memcg_params->memcg, gfp, nr_pages); } void __memcg_uncharge_slab(struct kmem_cache *cachep, int order) @@ -2831,7 +2779,6 @@ void __memcg_uncharge_slab(struct kmem_cache *cachep, int order) unsigned int nr_pages = 1 << order; memcg_uncharge_kmem(cachep->memcg_params->memcg, nr_pages); - atomic_sub(nr_pages, &cachep->memcg_params->nr_pages); } /* @@ -2847,8 +2794,7 @@ void __memcg_uncharge_slab(struct kmem_cache *cachep, int order) * Can't be called in interrupt context or from kernel threads. * This function needs to be called with rcu_read_lock() held. */ -struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, - gfp_t gfp) +struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep) { struct mem_cgroup *memcg; struct kmem_cache *memcg_cachep; @@ -2856,25 +2802,16 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, VM_BUG_ON(!cachep->memcg_params); VM_BUG_ON(!cachep->memcg_params->is_root_cache); - if (!current->mm || current->memcg_kmem_skip_account) + if (current->memcg_kmem_skip_account) return cachep; - rcu_read_lock(); - memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); - + memcg = get_mem_cgroup_from_mm(current->mm); if (!memcg_kmem_is_active(memcg)) goto out; memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg)); - if (likely(memcg_cachep)) { - cachep = memcg_cachep; - goto out; - } - - /* The corresponding put will be done in the workqueue. */ - if (!css_tryget_online(&memcg->css)) - goto out; - rcu_read_unlock(); + if (likely(memcg_cachep)) + return memcg_cachep; /* * If we are in a safe context (can wait, and not in interrupt @@ -2889,12 +2826,17 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, * defer everything. */ memcg_schedule_register_cache(memcg, cachep); - return cachep; out: - rcu_read_unlock(); + css_put(&memcg->css); return cachep; } +void __memcg_kmem_put_cache(struct kmem_cache *cachep) +{ + if (!is_root_cache(cachep)) + css_put(&cachep->memcg_params->memcg->css); +} + /* * We need to verify if the allocation against current->mm->owner's memcg is * possible for the given order. But the page is not allocated yet, so we'll @@ -2917,34 +2859,6 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) *_memcg = NULL; - /* - * Disabling accounting is only relevant for some specific memcg - * internal allocations. Therefore we would initially not have such - * check here, since direct calls to the page allocator that are - * accounted to kmemcg (alloc_kmem_pages and friends) only happen - * outside memcg core. We are mostly concerned with cache allocations, - * and by having this test at memcg_kmem_get_cache, we are already able - * to relay the allocation to the root cache and bypass the memcg cache - * altogether. - * - * There is one exception, though: the SLUB allocator does not create - * large order caches, but rather service large kmallocs directly from - * the page allocator. Therefore, the following sequence when backed by - * the SLUB allocator: - * - * memcg_stop_kmem_account(); - * kmalloc(<large_number>) - * memcg_resume_kmem_account(); - * - * would effectively ignore the fact that we should skip accounting, - * since it will drive us directly to this function without passing - * through the cache selector memcg_kmem_get_cache. Such large - * allocations are extremely rare but can happen, for instance, for the - * cache arrays. We bring this test here. - */ - if (!current->mm || current->memcg_kmem_skip_account) - return true; - memcg = get_mem_cgroup_from_mm(current->mm); if (!memcg_kmem_is_active(memcg)) { @@ -2985,10 +2899,6 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order) memcg_uncharge_kmem(memcg, 1 << order); page->mem_cgroup = NULL; } -#else -static inline void memcg_unregister_all_caches(struct mem_cgroup *memcg) -{ -} #endif /* CONFIG_MEMCG_KMEM */ #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -3539,12 +3449,6 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg, return 0; /* - * We are going to allocate memory for data shared by all memory - * cgroups so let's stop accounting here. - */ - memcg_stop_kmem_account(); - - /* * For simplicity, we won't allow this to be disabled. It also can't * be changed if the cgroup has children already, or if tasks had * already joined. @@ -3570,25 +3474,22 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg, goto out; } - memcg->kmemcg_id = memcg_id; - INIT_LIST_HEAD(&memcg->memcg_slab_caches); - /* - * We couldn't have accounted to this cgroup, because it hasn't got the - * active bit set yet, so this should succeed. + * We couldn't have accounted to this cgroup, because it hasn't got + * activated yet, so this should succeed. */ err = page_counter_limit(&memcg->kmem, nr_pages); VM_BUG_ON(err); static_key_slow_inc(&memcg_kmem_enabled_key); /* - * Setting the active bit after enabling static branching will + * A memory cgroup is considered kmem-active as soon as it gets + * kmemcg_id. Setting the id after enabling static branching will * guarantee no one starts accounting before all call sites are * patched. */ - memcg_kmem_set_active(memcg); + memcg->kmemcg_id = memcg_id; out: - memcg_resume_kmem_account(); return err; } @@ -3791,11 +3692,6 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) } #endif /* CONFIG_NUMA */ -static inline void mem_cgroup_lru_names_not_uptodate(void) -{ - BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); -} - static int memcg_stat_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); @@ -3803,6 +3699,8 @@ static int memcg_stat_show(struct seq_file *m, void *v) struct mem_cgroup *mi; unsigned int i; + BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS); + for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) { if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account) continue; @@ -4259,7 +4157,6 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) { int ret; - memcg->kmemcg_id = -1; ret = memcg_propagate_kmem(memcg); if (ret) return ret; @@ -4269,6 +4166,7 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) static void memcg_destroy_kmem(struct mem_cgroup *memcg) { + memcg_unregister_all_caches(memcg); mem_cgroup_sockets_destroy(memcg); } #else @@ -4724,17 +4622,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) free_percpu(memcg->stat); - /* - * We need to make sure that (at least for now), the jump label - * destruction code runs outside of the cgroup lock. This is because - * get_online_cpus(), which is called from the static_branch update, - * can't be called inside the cgroup_lock. cpusets are the ones - * enforcing this dependency, so if they ever change, we might as well. - * - * schedule_work() will guarantee this happens. Be careful if you need - * to move this code around, and make sure it is outside - * the cgroup_lock. - */ disarm_static_keys(memcg); kfree(memcg); } @@ -4804,6 +4691,10 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) vmpressure_init(&memcg->vmpressure); INIT_LIST_HEAD(&memcg->event_list); spin_lock_init(&memcg->event_list_lock); +#ifdef CONFIG_MEMCG_KMEM + memcg->kmemcg_id = -1; + INIT_LIST_HEAD(&memcg->memcg_slab_caches); +#endif return &memcg->css; @@ -4885,7 +4776,6 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) } spin_unlock(&memcg->event_list_lock); - memcg_unregister_all_caches(memcg); vmpressure_cleanup(&memcg->vmpressure); } |