diff options
| -rw-r--r-- | include/linux/memcontrol.h | 5 | ||||
| -rw-r--r-- | include/linux/slab.h | 5 | ||||
| -rw-r--r-- | mm/memcontrol.c | 163 | ||||
| -rw-r--r-- | mm/slab.c | 16 | ||||
| -rw-r--r-- | mm/slab.h | 146 | ||||
| -rw-r--r-- | mm/slab_common.c | 459 | ||||
| -rw-r--r-- | mm/slub.c | 38 |
7 files changed, 134 insertions, 698 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 83e2858aecf2..11fd18b3d6c6 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -317,7 +317,6 @@ struct mem_cgroup { /* Index in the kmem_cache->memcg_params.memcg_caches array */ int kmemcg_id; enum memcg_kmem_state kmem_state; - struct list_head kmem_caches; struct obj_cgroup __rcu *objcg; struct list_head objcg_list; /* list of inherited objcgs */ #endif @@ -1404,9 +1403,7 @@ static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg, } #endif -struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep, - struct obj_cgroup **objcgp); -void memcg_kmem_put_cache(struct kmem_cache *cachep); +struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep); #ifdef CONFIG_MEMCG_KMEM int __memcg_kmem_charge(struct mem_cgroup *memcg, gfp_t gfp, diff --git a/include/linux/slab.h b/include/linux/slab.h index 0884d82c55ee..8b1f91e320f9 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -155,8 +155,7 @@ struct kmem_cache *kmem_cache_create_usercopy(const char *name, void kmem_cache_destroy(struct kmem_cache *); int kmem_cache_shrink(struct kmem_cache *); -void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *); -void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *); +void memcg_create_kmem_cache(struct kmem_cache *cachep); /* * Please use this macro to create slab caches. Simply specify the @@ -580,8 +579,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) return __kmalloc_node(size, flags, node); } -int memcg_update_all_caches(int num_memcgs); - /** * kmalloc_array - allocate memory for an array. * @n: number of elements. diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5cb2a588cc10..874704c4a48a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -350,7 +350,7 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg, } /* - * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. + * This will be used as a shrinker list's index. * The main reason for not using cgroup id for this: * this works better in sparse environments, where we have a lot of memcgs, * but only a few kmem-limited. Or also, if we have, for instance, 200 @@ -569,20 +569,16 @@ ino_t page_cgroup_ino(struct page *page) unsigned long ino = 0; rcu_read_lock(); - if (PageSlab(page) && !PageTail(page)) { - memcg = memcg_from_slab_page(page); - } else { - memcg = page->mem_cgroup; + memcg = page->mem_cgroup; - /* - * The lowest bit set means that memcg isn't a valid - * memcg pointer, but a obj_cgroups pointer. - * In this case the page is shared and doesn't belong - * to any specific memory cgroup. - */ - if ((unsigned long) memcg & 0x1UL) - memcg = NULL; - } + /* + * The lowest bit set means that memcg isn't a valid + * memcg pointer, but a obj_cgroups pointer. + * In this case the page is shared and doesn't belong + * to any specific memory cgroup. + */ + if ((unsigned long) memcg & 0x1UL) + memcg = NULL; while (memcg && !(memcg->css.flags & CSS_ONLINE)) memcg = parent_mem_cgroup(memcg); @@ -2822,12 +2818,18 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p) page = virt_to_head_page(p); /* - * Slab pages don't have page->mem_cgroup set because corresponding - * kmem caches can be reparented during the lifetime. That's why - * memcg_from_slab_page() should be used instead. + * Slab objects are accounted individually, not per-page. + * Memcg membership data for each individual object is saved in + * the page->obj_cgroups. */ - if (PageSlab(page)) - return memcg_from_slab_page(page); + if (page_has_obj_cgroups(page)) { + struct obj_cgroup *objcg; + unsigned int off; + + off = obj_to_index(page->slab_cache, page, p); + objcg = page_obj_cgroups(page)[off]; + return obj_cgroup_memcg(objcg); + } /* All other pages use page->mem_cgroup */ return page->mem_cgroup; @@ -2882,9 +2884,7 @@ static int memcg_alloc_cache_id(void) else if (size > MEMCG_CACHES_MAX_SIZE) size = MEMCG_CACHES_MAX_SIZE; - err = memcg_update_all_caches(size); - if (!err) - err = memcg_update_all_list_lrus(size); + err = memcg_update_all_list_lrus(size); if (!err) memcg_nr_cache_ids = size; @@ -2903,7 +2903,6 @@ static void memcg_free_cache_id(int id) } struct memcg_kmem_cache_create_work { - struct mem_cgroup *memcg; struct kmem_cache *cachep; struct work_struct work; }; @@ -2912,33 +2911,24 @@ static void memcg_kmem_cache_create_func(struct work_struct *w) { struct memcg_kmem_cache_create_work *cw = container_of(w, struct memcg_kmem_cache_create_work, work); - struct mem_cgroup *memcg = cw->memcg; struct kmem_cache *cachep = cw->cachep; - memcg_create_kmem_cache(memcg, cachep); + memcg_create_kmem_cache(cachep); - css_put(&memcg->css); kfree(cw); } /* * Enqueue the creation of a per-memcg kmem_cache. */ -static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, - struct kmem_cache *cachep) +static void memcg_schedule_kmem_cache_create(struct kmem_cache *cachep) { struct memcg_kmem_cache_create_work *cw; - if (!css_tryget_online(&memcg->css)) - return; - cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN); - if (!cw) { - css_put(&memcg->css); + if (!cw) return; - } - cw->memcg = memcg; cw->cachep = cachep; INIT_WORK(&cw->work, memcg_kmem_cache_create_func); @@ -2946,102 +2936,26 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, } /** - * memcg_kmem_get_cache: select the correct per-memcg cache for allocation + * memcg_kmem_get_cache: select memcg or root cache for allocation * @cachep: the original global kmem cache * * Return the kmem_cache we're supposed to use for a slab allocation. - * We try to use the current memcg's version of the cache. * * If the cache does not exist yet, if we are the first user of it, we * create it asynchronously in a workqueue and let the current allocation * go through with the original cache. - * - * This function takes a reference to the cache it returns to assure it - * won't get destroyed while we are working with it. Once the caller is - * done with it, memcg_kmem_put_cache() must be called to release the - * reference. */ -struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep, - struct obj_cgroup **objcgp) +struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep) { - struct mem_cgroup *memcg; struct kmem_cache *memcg_cachep; - struct memcg_cache_array *arr; - int kmemcg_id; - VM_BUG_ON(!is_root_cache(cachep)); - - if (memcg_kmem_bypass()) + memcg_cachep = READ_ONCE(cachep->memcg_params.memcg_cache); + if (unlikely(!memcg_cachep)) { + memcg_schedule_kmem_cache_create(cachep); return cachep; - - rcu_read_lock(); - - if (unlikely(current->active_memcg)) - memcg = current->active_memcg; - else - memcg = mem_cgroup_from_task(current); - - if (!memcg || memcg == root_mem_cgroup) - goto out_unlock; - - kmemcg_id = READ_ONCE(memcg->kmemcg_id); - if (kmemcg_id < 0) - goto out_unlock; - - arr = rcu_dereference(cachep->memcg_params.memcg_caches); - - /* - * Make sure we will access the up-to-date value. The code updating - * memcg_caches issues a write barrier to match the data dependency - * barrier inside READ_ONCE() (see memcg_create_kmem_cache()). - */ - memcg_cachep = READ_ONCE(arr->entries[kmemcg_id]); - - /* - * If we are in a safe context (can wait, and not in interrupt - * context), we could be be predictable and return right away. - * This would guarantee that the allocation being performed - * already belongs in the new cache. - * - * However, there are some clashes that can arrive from locking. - * For instance, because we acquire the slab_mutex while doing - * memcg_create_kmem_cache, this means no further allocation - * could happen with the slab_mutex held. So it's better to - * defer everything. - * - * If the memcg is dying or memcg_cache is about to be released, - * don't bother creating new kmem_caches. Because memcg_cachep - * is ZEROed as the fist step of kmem offlining, we don't need - * percpu_ref_tryget_live() here. css_tryget_online() check in - * memcg_schedule_kmem_cache_create() will prevent us from - * creation of a new kmem_cache. - */ - if (unlikely(!memcg_cachep)) - memcg_schedule_kmem_cache_create(memcg, cachep); - else if (percpu_ref_tryget(&memcg_cachep->memcg_params.refcnt)) { - struct obj_cgroup *objcg = rcu_dereference(memcg->objcg); - - if (!objcg || !obj_cgroup_tryget(objcg)) { - percpu_ref_put(&memcg_cachep->memcg_params.refcnt); - goto out_unlock; - } - - *objcgp = objcg; - cachep = memcg_cachep; } -out_unlock: - rcu_read_unlock(); - return cachep; -} -/** - * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache - * @cachep: the cache returned by memcg_kmem_get_cache - */ -void memcg_kmem_put_cache(struct kmem_cache *cachep) -{ - if (!is_root_cache(cachep)) - percpu_ref_put(&cachep->memcg_params.refcnt); + return memcg_cachep; } /** @@ -3731,7 +3645,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) */ memcg->kmemcg_id = memcg_id; memcg->kmem_state = KMEM_ONLINE; - INIT_LIST_HEAD(&memcg->kmem_caches); return 0; } @@ -3744,22 +3657,13 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) if (memcg->kmem_state != KMEM_ONLINE) return; - /* - * Clear the online state before clearing memcg_caches array - * entries. The slab_mutex in memcg_deactivate_kmem_caches() - * guarantees that no cache will be created for this cgroup - * after we are done (see memcg_create_kmem_cache()). - */ + memcg->kmem_state = KMEM_ALLOCATED; parent = parent_mem_cgroup(memcg); if (!parent) parent = root_mem_cgroup; - /* - * Deactivate and reparent kmem_caches and objcgs. - */ - memcg_deactivate_kmem_caches(memcg, parent); memcg_reparent_objcgs(memcg, parent); kmemcg_id = memcg->kmemcg_id; @@ -5384,9 +5288,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) /* The following stuff does not apply to the root */ if (!parent) { -#ifdef CONFIG_MEMCG_KMEM - INIT_LIST_HEAD(&memcg->kmem_caches); -#endif root_mem_cgroup = memcg; return &memcg->css; } diff --git a/mm/slab.c b/mm/slab.c index 1e90b67735aa..0dd6956585dc 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1249,7 +1249,7 @@ void __init kmem_cache_init(void) nr_node_ids * sizeof(struct kmem_cache_node *), SLAB_HWCACHE_ALIGN, 0, 0); list_add(&kmem_cache->list, &slab_caches); - memcg_link_cache(kmem_cache, NULL); + memcg_link_cache(kmem_cache); slab_state = PARTIAL; /* @@ -2253,17 +2253,6 @@ int __kmem_cache_shrink(struct kmem_cache *cachep) return (ret ? 1 : 0); } -#ifdef CONFIG_MEMCG -void __kmemcg_cache_deactivate(struct kmem_cache *cachep) -{ - __kmem_cache_shrink(cachep); -} - -void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) -{ -} -#endif - int __kmem_cache_shutdown(struct kmem_cache *cachep) { return __kmem_cache_shrink(cachep); @@ -3872,7 +3861,8 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit, return ret; lockdep_assert_held(&slab_mutex); - for_each_memcg_cache(c, cachep) { + c = memcg_cache(cachep); + if (c) { /* return value determined by the root cache only */ __do_tune_cpucache(c, limit, batchcount, shared, gfp); } diff --git a/mm/slab.h b/mm/slab.h index 1f067e8bc377..e716b80befc2 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -32,66 +32,25 @@ struct kmem_cache { #else /* !CONFIG_SLOB */ -struct memcg_cache_array { - struct rcu_head rcu; - struct kmem_cache *entries[0]; -}; - /* * This is the main placeholder for memcg-related information in kmem caches. - * Both the root cache and the child caches will have it. For the root cache, - * this will hold a dynamically allocated array large enough to hold - * information about the currently limited memcgs in the system. To allow the - * array to be accessed without taking any locks, on relocation we free the old - * version only after a grace period. - * - * Root and child caches hold different metadata. + * Both the root cache and the child cache will have it. Some fields are used + * in both cases, other are specific to root caches. * * @root_cache: Common to root and child caches. NULL for root, pointer to * the root cache for children. * * The following fields are specific to root caches. * - * @memcg_caches: kmemcg ID indexed table of child caches. This table is - * used to index child cachces during allocation and cleared - * early during shutdown. - * - * @root_caches_node: List node for slab_root_caches list. - * - * @children: List of all child caches. While the child caches are also - * reachable through @memcg_caches, a child cache remains on - * this list until it is actually destroyed. - * - * The following fields are specific to child caches. - * - * @memcg: Pointer to the memcg this cache belongs to. - * - * @children_node: List node for @root_cache->children list. - * - * @kmem_caches_node: List node for @memcg->kmem_caches list. + * @memcg_cache: pointer to memcg kmem cache, used by all non-root memory + * cgroups. + * @root_caches_node: list node for slab_root_caches list. */ struct memcg_cache_params { struct kmem_cache *root_cache; - union { - struct { - struct memcg_cache_array __rcu *memcg_caches; - struct list_head __root_caches_node; - struct list_head children; - bool dying; - }; - struct { - struct mem_cgroup *memcg; - struct list_head children_node; - struct list_head kmem_caches_node; - struct percpu_ref refcnt; - - void (*work_fn)(struct kmem_cache *); - union { - struct rcu_head rcu_head; - struct work_struct work; - }; - }; - }; + + struct kmem_cache *memcg_cache; + struct list_head __root_caches_node; }; #endif /* CONFIG_SLOB */ @@ -236,8 +195,6 @@ bool __kmem_cache_empty(struct kmem_cache *); int __kmem_cache_shutdown(struct kmem_cache *); void __kmem_cache_release(struct kmem_cache *); int __kmem_cache_shrink(struct kmem_cache *); -void __kmemcg_cache_deactivate(struct kmem_cache *s); -void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s); void slab_kmem_cache_release(struct kmem_cache *); void kmem_cache_shrink_all(struct kmem_cache *s); @@ -311,14 +268,6 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla extern struct list_head slab_root_caches; #define root_caches_node memcg_params.__root_caches_node -/* - * Iterate over all memcg caches of the given root cache. The caller must hold - * slab_mutex. - */ -#define for_each_memcg_cache(iter, root) \ - list_for_each_entry(iter, &(root)->memcg_params.children, \ - memcg_params.children_node) - static inline bool is_root_cache(struct kmem_cache *s) { return !s->memcg_params.root_cache; @@ -349,6 +298,13 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) return s->memcg_params.root_cache; } +static inline struct kmem_cache *memcg_cache(struct kmem_cache *s) +{ + if (is_root_cache(s)) + return s->memcg_params.memcg_cache; + return NULL; +} + static inline struct obj_cgroup **page_obj_cgroups(struct page *page) { /* @@ -361,25 +317,9 @@ static inline struct obj_cgroup **page_obj_cgroups(struct page *page) ((unsigned long)page->obj_cgroups & ~0x1UL); } -/* - * Expects a pointer to a slab page. Please note, that PageSlab() check - * isn't sufficient, as it returns true also for tail compound slab pages, - * which do not have slab_cache pointer set. - * So this function assumes that the page can pass PageSlab() && !PageTail() - * check. - * - * The kmem_cache can be reparented asynchronously. The caller must ensure - * the memcg lifetime, e.g. by taking rcu_read_lock() or cgroup_mutex. - */ -static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) +static inline bool page_has_obj_cgroups(struct page *page) { - struct kmem_cache *s; - - s = READ_ONCE(page->slab_cache); - if (s && !is_root_cache(s)) - return READ_ONCE(s->memcg_params.memcg); - - return NULL; + return ((unsigned long)page->obj_cgroups & 0x1UL); } static inline int memcg_alloc_page_obj_cgroups(struct page *page, @@ -418,17 +358,25 @@ static inline struct kmem_cache *memcg_slab_pre_alloc_hook(struct kmem_cache *s, size_t objects, gfp_t flags) { struct kmem_cache *cachep; + struct obj_cgroup *objcg; + + if (memcg_kmem_bypass()) + return s; - cachep = memcg_kmem_get_cache(s, objcgp); + cachep = memcg_kmem_get_cache(s); if (is_root_cache(cachep)) return s; - if (obj_cgroup_charge(*objcgp, flags, objects * obj_full_size(s))) { - obj_cgroup_put(*objcgp); - memcg_kmem_put_cache(cachep); + objcg = get_obj_cgroup_from_current(); + if (!objcg) + return s; + + if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) { + obj_cgroup_put(objcg); cachep = NULL; } + *objcgp = objcg; return cachep; } @@ -467,7 +415,6 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, } } obj_cgroup_put(objcg); - memcg_kmem_put_cache(s); } static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page, @@ -491,7 +438,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page, } extern void slab_init_memcg_params(struct kmem_cache *); -extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); +extern void memcg_link_cache(struct kmem_cache *s); #else /* CONFIG_MEMCG_KMEM */ @@ -499,9 +446,6 @@ extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); #define slab_root_caches slab_caches #define root_caches_node list -#define for_each_memcg_cache(iter, root) \ - for ((void)(iter), (void)(root); 0; ) - static inline bool is_root_cache(struct kmem_cache *s) { return true; @@ -523,7 +467,17 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) return s; } -static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) +static inline struct kmem_cache *memcg_cache(struct kmem_cache *s) +{ + return NULL; +} + +static inline bool page_has_obj_cgroups(struct page *page) +{ + return false; +} + +static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) { return NULL; } @@ -560,8 +514,7 @@ static inline void slab_init_memcg_params(struct kmem_cache *s) { } -static inline void memcg_link_cache(struct kmem_cache *s, - struct mem_cgroup *memcg) +static inline void memcg_link_cache(struct kmem_cache *s) { } @@ -582,17 +535,14 @@ static __always_inline int charge_slab_page(struct page *page, gfp_t gfp, int order, struct kmem_cache *s) { -#ifdef CONFIG_MEMCG_KMEM if (memcg_kmem_enabled() && !is_root_cache(s)) { int ret; ret = memcg_alloc_page_obj_cgroups(page, s, gfp); if (ret) return ret; - - percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order); } -#endif + mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), PAGE_SIZE << order); return 0; @@ -601,12 +551,9 @@ static __always_inline int charge_slab_page(struct page *page, static __always_inline void uncharge_slab_page(struct page *page, int order, struct kmem_cache *s) { -#ifdef CONFIG_MEMCG_KMEM - if (memcg_kmem_enabled() && !is_root_cache(s)) { + if (memcg_kmem_enabled() && !is_root_cache(s)) memcg_free_page_obj_cgroups(page); - percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order); - } -#endif + mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), -(PAGE_SIZE << order)); } @@ -749,9 +696,6 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) void *slab_start(struct seq_file *m, loff_t *pos); void *slab_next(struct seq_file *m, void *p, loff_t *pos); void slab_stop(struct seq_file *m, void *p); -void *memcg_slab_start(struct seq_file *m, loff_t *pos); -void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos); -void memcg_slab_stop(struct seq_file *m, void *p); int memcg_slab_show(struct seq_file *m, void *p); #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) diff --git a/mm/slab_common.c b/mm/slab_common.c index f86431d0de73..e752132eb64d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -133,141 +133,36 @@ int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, #ifdef CONFIG_MEMCG_KMEM LIST_HEAD(slab_root_caches); -static DEFINE_SPINLOCK(memcg_kmem_wq_lock); - -static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref); void slab_init_memcg_params(struct kmem_cache *s) { s->memcg_params.root_cache = NULL; - RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL); - INIT_LIST_HEAD(&s->memcg_params.children); - s->memcg_params.dying = false; + s->memcg_params.memcg_cache = NULL; } -static int init_memcg_params(struct kmem_cache *s, - struct kmem_cache *root_cache) +static void init_memcg_params(struct kmem_cache *s, + struct kmem_cache *root_cache) { - struct memcg_cache_array *arr; - - if (root_cache) { - int ret = percpu_ref_init(&s->memcg_params.refcnt, - kmemcg_cache_shutdown, - 0, GFP_KERNEL); - if (ret) - return ret; - + if (root_cache) s->memcg_params.root_cache = root_cache; - INIT_LIST_HEAD(&s->memcg_params.children_node); - INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node); - return 0; - } - - slab_init_memcg_params(s); - - if (!memcg_nr_cache_ids) - return 0; - - arr = kvzalloc(sizeof(struct memcg_cache_array) + - memcg_nr_cache_ids * sizeof(void *), - GFP_KERNEL); - if (!arr) - return -ENOMEM; - - RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr); - return 0; -} - -static void destroy_memcg_params(struct kmem_cache *s) -{ - if (is_root_cache(s)) { - kvfree(rcu_access_pointer(s->memcg_params.memcg_caches)); - } else { - mem_cgroup_put(s->memcg_params.memcg); - WRITE_ONCE(s->memcg_params.memcg, NULL); - percpu_ref_exit(&s->memcg_params.refcnt); - } -} - -static void free_memcg_params(struct rcu_head *rcu) -{ - struct memcg_cache_array *old; - - old = container_of(rcu, struct memcg_cache_array, rcu); - kvfree(old); -} - -static int update_memcg_params(struct kmem_cache *s, int new_array_size) -{ - struct memcg_cache_array *old, *new; - - new = kvzalloc(sizeof(struct memcg_cache_array) + - new_array_size * sizeof(void *), GFP_KERNEL); - if (!new) - return -ENOMEM; - - old = rcu_dereference_protected(s->memcg_params.memcg_caches, - lockdep_is_held(&slab_mutex)); - if (old) - memcpy(new->entries, old->entries, - memcg_nr_cache_ids * sizeof(void *)); - - rcu_assign_pointer(s->memcg_params.memcg_caches, new); - if (old) - call_rcu(&old->rcu, free_memcg_params); - return 0; + else + slab_init_memcg_params(s); } -int memcg_update_all_caches(int num_memcgs) +void memcg_link_cache(struct kmem_cache *s) { - struct kmem_cache *s; - int ret = 0; - - mutex_lock(&slab_mutex); - list_for_each_entry(s, &slab_root_caches, root_caches_node) { - ret = update_memcg_params(s, num_memcgs); - /* - * Instead of freeing the memory, we'll just leave the caches - * up to this point in an updated state. - */ - if (ret) - break; - } - mutex_unlock(&slab_mutex); - return ret; -} - -void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg) -{ - if (is_root_cache(s)) { + if (is_root_cache(s)) list_add(&s->root_caches_node, &slab_root_caches); - } else { - css_get(&memcg->css); - s->memcg_params.memcg = memcg; - list_add(&s->memcg_params.children_node, - &s->memcg_params.root_cache->memcg_params.children); - list_add(&s->memcg_params.kmem_caches_node, - &s->memcg_params.memcg->kmem_caches); - } } static void memcg_unlink_cache(struct kmem_cache *s) { - if (is_root_cache(s)) { + if (is_root_cache(s)) list_del(&s->root_caches_node); - } else { - list_del(&s->memcg_params.children_node); - list_del(&s->memcg_params.kmem_caches_node); - } } #else -static inline int init_memcg_params(struct kmem_cache *s, - struct kmem_cache *root_cache) -{ - return 0; -} - -static inline void destroy_memcg_params(struct kmem_cache *s) +static inline void init_memcg_params(struct kmem_cache *s, + struct kmem_cache *root_cache) { } @@ -328,14 +223,6 @@ int slab_unmergeable(struct kmem_cache *s) if (s->refcount < 0) return 1; -#ifdef CONFIG_MEMCG_KMEM - /* - * Skip the dying kmem_cache. - */ - if (s->memcg_params.dying) - return 1; -#endif - return 0; } @@ -390,7 +277,7 @@ static struct kmem_cache *create_cache(const char *name, unsigned int object_size, unsigned int align, slab_flags_t flags, unsigned int useroffset, unsigned int usersize, void (*ctor)(void *), - struct mem_cgroup *memcg, struct kmem_cache *root_cache) + struct kmem_cache *root_cache) { struct kmem_cache *s; int err; @@ -410,24 +297,20 @@ static struct kmem_cache *create_cache(const char *name, s->useroffset = useroffset; s->usersize = usersize; - err = init_memcg_params(s, root_cache); - if (err) - goto out_free_cache; - + init_memcg_params(s, root_cache); err = __kmem_cache_create(s, flags); if (err) goto out_free_cache; s->refcount = 1; list_add(&s->list, &slab_caches); - memcg_link_cache(s, memcg); + memcg_link_cache(s); out: if (err) return ERR_PTR(err); return s; out_free_cache: - destroy_memcg_params(s); kmem_cache_free(kmem_cache, s); goto out; } @@ -514,7 +397,7 @@ kmem_cache_create_usercopy(const char *name, s = create_cache(cache_name, size, calculate_alignment(flags, align, size), - flags, useroffset, usersize, ctor, NULL, NULL); + flags, useroffset, usersize, ctor, NULL); if (IS_ERR(s)) { err = PTR_ERR(s); kfree_const(cache_name); @@ -639,51 +522,27 @@ static int shutdown_cache(struct kmem_cache *s) #ifdef CONFIG_MEMCG_KMEM /* - * memcg_create_kmem_cache - Create a cache for a memory cgroup. - * @memcg: The memory cgroup the new cache is for. + * memcg_create_kmem_cache - Create a cache for non-root memory cgroups. * @root_cache: The parent of the new cache. * * This function attempts to create a kmem cache that will serve allocation - * requests going from @memcg to @root_cache. The new cache inherits properties - * from its parent. + * requests going all non-root memory cgroups to @root_cache. The new cache + * inherits properties from its parent. */ -void memcg_create_kmem_cache(struct mem_cgroup *memcg, - struct kmem_cache *root_cache) +void memcg_create_kmem_cache(struct kmem_cache *root_cache) { - static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ - struct cgroup_subsys_state *css = &memcg->css; - struct memcg_cache_array *arr; struct kmem_cache *s = NULL; char *cache_name; - int idx; get_online_cpus(); get_online_mems(); mutex_lock(&slab_mutex); - /* - * The memory cgroup could have been offlined while the cache - * creation work was pending. - */ - if (memcg->kmem_state != KMEM_ONLINE) + if (root_cache->memcg_params.memcg_cache) goto out_unlock; - idx = memcg_cache_id(memcg); - arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches, - lockdep_is_held(&slab_mutex)); - - /* - * Since per-memcg caches are created asynchronously on first - * allocation (see memcg_kmem_get_cache()), several threads can try to - * create the same cache, but only one of them may succeed. - */ - if (arr->entries[idx]) - goto out_unlock; - - cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf)); - cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name, - css->serial_nr, memcg_name_buf); + cache_name = kasprintf(GFP_KERNEL, "%s-memcg", root_cache->name); if (!cache_name) goto out_unlock; @@ -691,7 +550,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, root_cache->align, root_cache->flags & CACHE_CREATE_MASK, root_cache->useroffset, root_cache->usersize, - root_cache->ctor, memcg, root_cache); + root_cache->ctor, root_cache); /* * If we could not create a memcg cache, do not complain, because * that's not critical at all as we can always proceed with the root @@ -708,7 +567,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, * initialized. */ smp_wmb(); - arr->entries[idx] = s; + root_cache->memcg_params.memcg_cache = s; out_unlock: mutex_unlock(&slab_mutex); @@ -717,231 +576,40 @@ out_unlock: put_online_cpus(); } -static void kmemcg_workfn(struct work_struct *work) -{ - struct kmem_cache *s = container_of(work, struct kmem_cache, - memcg_params.work); - - get_online_cpus(); - get_online_mems(); - - mutex_lock(&slab_mutex); - s->memcg_params.work_fn(s); - mutex_unlock(&slab_mutex); - - put_online_mems(); - put_online_cpus(); -} - -static void kmemcg_rcufn(struct rcu_head *head) -{ - struct kmem_cache *s = container_of(head, struct kmem_cache, - memcg_params.rcu_head); - - /* - * We need to grab blocking locks. Bounce to ->work. The - * work item shares the space with the RCU head and can't be - * initialized earlier. - */ - INIT_WORK(&s->memcg_params.work, kmemcg_workfn); - queue_work(memcg_kmem_cache_wq, &s->memcg_params.work); -} - -static void kmemcg_cache_shutdown_fn(struct kmem_cache *s) -{ - WARN_ON(shutdown_cache(s)); -} - -static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref) -{ - struct kmem_cache *s = container_of(percpu_ref, struct kmem_cache, - memcg_params.refcnt); - unsigned long flags; - - spin_lock_irqsave(&memcg_kmem_wq_lock, flags); - if (s->memcg_params.root_cache->memcg_params.dying) - goto unlock; - - s->memcg_params.work_fn = kmemcg_cache_shutdown_fn; - INIT_WORK(&s->memcg_params.work, kmemcg_workfn); - queue_work(memcg_kmem_cache_wq, &s->memcg_params.work); - -unlock: - spin_unlock_irqrestore(&memcg_kmem_wq_lock, flags); -} - -static void kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) -{ - __kmemcg_cache_deactivate_after_rcu(s); - percpu_ref_kill(&s->memcg_params.refcnt); -} - -static void kmemcg_cache_deactivate(struct kmem_cache *s) -{ - if (WARN_ON_ONCE(is_root_cache(s))) - return; - - __kmemcg_cache_deactivate(s); - s->flags |= SLAB_DEACTIVATED; - - /* - * memcg_kmem_wq_lock is used to synchronize memcg_params.dying - * flag and make sure that no new kmem_cache deactivation tasks - * are queued (see flush_memcg_workqueue() ). - */ - spin_lock_irq(&memcg_kmem_wq_lock); - if (s->memcg_params.root_cache->memcg_params.dying) - goto unlock; - - s->memcg_params.work_fn = kmemcg_cache_deactivate_after_rcu; - call_rcu(&s->memcg_params.rcu_head, kmemcg_rcufn); -unlock: - spin_unlock_irq(&memcg_kmem_wq_lock); -} - -void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg, - struct mem_cgroup *parent) -{ - int idx; - struct memcg_cache_array *arr; - struct kmem_cache *s, *c; - unsigned int nr_reparented; - - idx = memcg_cache_id(memcg); - - get_online_cpus(); - get_online_mems(); - - mutex_lock(&slab_mutex); - list_for_each_entry(s, &slab_root_caches, root_caches_node) { - arr = rcu_dereference_protected(s->memcg_params.memcg_caches, - lockdep_is_held(&slab_mutex)); - c = arr->entries[idx]; - if (!c) - continue; - - kmemcg_cache_deactivate(c); - arr->entries[idx] = NULL; - } - nr_reparented = 0; - list_for_each_entry(s, &memcg->kmem_caches, - memcg_params.kmem_caches_node) { - WRITE_ONCE(s->memcg_params.memcg, parent); - css_put(&memcg->css); - nr_reparented++; - } - if (nr_reparented) { - list_splice_init(&memcg->kmem_caches, - &parent->kmem_caches); - css_get_many(&parent->css, nr_reparented); - } - mutex_unlock(&slab_mutex); - - put_online_mems(); - put_online_cpus(); -} - static int shutdown_memcg_caches(struct kmem_cache *s) { - struct memcg_cache_array *arr; - struct kmem_cache *c, *c2; - LIST_HEAD(busy); - int i; - BUG_ON(!is_root_cache(s)); - /* - * First, shutdown active caches, i.e. caches that belong to online - * memory cgroups. - */ - arr = rcu_dereference_protected(s->memcg_params.memcg_caches, - lockdep_is_held(&slab_mutex)); - for_each_memcg_cache_index(i) { - c = arr->entries[i]; - if (!c) - continue; - if (shutdown_cache(c)) - /* - * The cache still has objects. Move it to a temporary - * list so as not to try to destroy it for a second - * time while iterating over inactive caches below. - */ - list_move(&c->memcg_params.children_node, &busy); - else - /* - * The cache is empty and will be destroyed soon. Clear - * the pointer to it in the memcg_caches array so that - * it will never be accessed even if the root cache - * stays alive. - */ - arr->entries[i] = NULL; - } - - /* - * Second, shutdown all caches left from memory cgroups that are now - * offline. - */ - list_for_each_entry_safe(c, c2, &s->memcg_params.children, - memcg_params.children_node) - shutdown_cache(c); - - list_splice(&busy, &s->memcg_params.children); + if (s->memcg_params.memcg_cache) + WARN_ON(shutdown_cache(s->memcg_params.memcg_cache)); - /* - * A cache being destroyed must be empty. In particular, this means - * that all per memcg caches attached to it must be empty too. - */ - if (!list_empty(&s->memcg_params.children)) - return -EBUSY; return 0; } -static void memcg_set_kmem_cache_dying(struct kmem_cache *s) -{ - spin_lock_irq(&memcg_kmem_wq_lock); - s->memcg_params.dying = true; - spin_unlock_irq(&memcg_kmem_wq_lock); -} - static void flush_memcg_workqueue(struct kmem_cache *s) { /* - * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make - * sure all registered rcu callbacks have been invoked. - */ - rcu_barrier(); - - /* * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB * deactivates the memcg kmem_caches through workqueue. Make sure all * previous workitems on workqueue are processed. */ if (likely(memcg_kmem_cache_wq)) flush_workqueue(memcg_kmem_cache_wq); - - /* - * If we're racing with children kmem_cache deactivation, it might - * take another rcu grace period to complete their destruction. - * At this moment the corresponding percpu_ref_kill() call should be - * done, but it might take another rcu grace period to complete - * switching to the atomic mode. - * Please, note that we check without grabbing the slab_mutex. It's safe - * because at this moment the children list can't grow. - */ - if (!list_empty(&s->memcg_params.children)) - rcu_barrier(); } #else static inline int shutdown_memcg_caches(struct kmem_cache *s) { return 0; } + +static inline void flush_memcg_workqueue(struct kmem_cache *s) +{ +} #endif /* CONFIG_MEMCG_KMEM */ void slab_kmem_cache_release(struct kmem_cache *s) { __kmem_cache_release(s); - destroy_memcg_params(s); kfree_const(s->name); kmem_cache_free(kmem_cache, s); } @@ -953,6 +621,8 @@ void kmem_cache_destroy(struct kmem_cache *s) if (unlikely(!s)) return; + flush_memcg_workqueue(s); + get_online_cpus(); get_online_mems(); @@ -962,22 +632,6 @@ void kmem_cache_destroy(struct kmem_cache *s) if (s->refcount) goto out_unlock; -#ifdef CONFIG_MEMCG_KMEM - memcg_set_kmem_cache_dying(s); - - mutex_unlock(&slab_mutex); - - put_online_mems(); - put_online_cpus(); - - flush_memcg_workqueue(s); - - get_online_cpus(); - get_online_mems(); - - mutex_lock(&slab_mutex); -#endif - err = shutdown_memcg_caches(s); if (!err) err = shutdown_cache(s); @@ -1019,7 +673,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep) EXPORT_SYMBOL(kmem_cache_shrink); /** - * kmem_cache_shrink_all - shrink a cache and all memcg caches for root cache + * kmem_cache_shrink_all - shrink root and memcg caches * @s: The cache pointer */ void kmem_cache_shrink_all(struct kmem_cache *s) @@ -1036,21 +690,11 @@ void kmem_cache_shrink_all(struct kmem_cache *s) kasan_cache_shrink(s); __kmem_cache_shrink(s); - /* - * We have to take the slab_mutex to protect from the memcg list - * modification. - */ - mutex_lock(&slab_mutex); - for_each_memcg_cache(c, s) { - /* - * Don't need to shrink deactivated memcg caches. - */ - if (s->flags & SLAB_DEACTIVATED) - continue; + c = memcg_cache(s); + if (c) { kasan_cache_shrink(c); __kmem_cache_shrink(c); } - mutex_unlock(&slab_mutex); put_online_mems(); put_online_cpus(); } @@ -1105,7 +749,7 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name, create_boot_cache(s, name, size, flags, useroffset, usersize); list_add(&s->list, &slab_caches); - memcg_link_cache(s, NULL); + memcg_link_cache(s); s->refcount = 1; return s; } @@ -1483,7 +1127,8 @@ memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) if (!is_root_cache(s)) return; - for_each_memcg_cache(c, s) { + c = memcg_cache(s); + if (c) { memset(&sinfo, 0, sizeof(sinfo)); get_slabinfo(c, &sinfo); @@ -1614,7 +1259,7 @@ module_init(slab_proc_init); #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_MEMCG_KMEM) /* - * Display information about kmem caches that have child memcg caches. + * Display information about kmem caches that have memcg cache. */ static int memcg_slabinfo_show(struct seq_file *m, void *unused) { @@ -1626,9 +1271,9 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused) seq_puts(m, " <active_slabs> <num_slabs>\n"); list_for_each_entry(s, &slab_root_caches, root_caches_node) { /* - * Skip kmem caches that don't have any memcg children. + * Skip kmem caches that don't have the memcg cache. */ - if (list_empty(&s->memcg_params.children)) + if (!s->memcg_params.memcg_cache) continue; memset(&sinfo, 0, sizeof(sinfo)); @@ -1637,23 +1282,13 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused) cache_name(s), sinfo.active_objs, sinfo.num_objs, sinfo.active_slabs, sinfo.num_slabs); - for_each_memcg_cache(c, s) { - struct cgroup_subsys_state *css; - char *status = ""; - - css = &c->memcg_params.memcg->css; - if (!(css->flags & CSS_ONLINE)) - status = ":dead"; - else if (c->flags & SLAB_DEACTIVATED) - status = ":deact"; - - memset(&sinfo, 0, sizeof(sinfo)); - get_slabinfo(c, &sinfo); - seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n", - cache_name(c), css->id, status, - sinfo.active_objs, sinfo.num_objs, - sinfo.active_slabs, sinfo.num_slabs); - } + c = s->memcg_params.memcg_cache; + memset(&sinfo, 0, sizeof(sinfo)); + get_slabinfo(c, &sinfo); + seq_printf(m, "%-17s %4d %6lu %6lu %6lu %6lu\n", + cache_name(c), root_mem_cgroup->css.id, + sinfo.active_objs, sinfo.num_objs, + sinfo.active_slabs, sinfo.num_slabs); } mutex_unlock(&slab_mutex); return 0; diff --git a/mm/slub.c b/mm/slub.c index 47e63b1100d4..44a48a08a691 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4204,36 +4204,6 @@ int __kmem_cache_shrink(struct kmem_cache *s) return ret; } -#ifdef CONFIG_MEMCG -void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s) -{ - /* - * Called with all the locks held after a sched RCU grace period. - * Even if @s becomes empty after shrinking, we can't know that @s - * doesn't have allocations already in-flight and thus can't - * destroy @s until the associated memcg is released. - * - * However, let's remove the sysfs files for empty caches here. - * Each cache has a lot of interface files which aren't - * particularly useful for empty draining caches; otherwise, we can - * easily end up with millions of unnecessary sysfs files on - * systems which have a lot of memory and transient cgroups. - */ - if (!__kmem_cache_shrink(s)) - sysfs_slab_remove(s); -} - -void __kmemcg_cache_deactivate(struct kmem_cache *s) -{ - /* - * Disable empty slabs caching. Used to avoid pinning offline - * memory cgroups by kmem pages that can be freed. - */ - slub_set_cpu_partial(s, 0); - s->min_partial = 0; -} -#endif /* CONFIG_MEMCG */ - static int slab_mem_going_offline_callback(void *arg) { struct kmem_cache *s; @@ -4390,7 +4360,7 @@ static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache) } slab_init_memcg_params(s); list_add(&s->list, &slab_caches); - memcg_link_cache(s, NULL); + memcg_link_cache(s); return s; } @@ -4458,7 +4428,8 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, s->object_size = max(s->object_size, size); s->inuse = max(s->inuse, ALIGN(size, sizeof(void *))); - for_each_memcg_cache(c, s) { + c = memcg_cache(s); + if (c) { c->object_size = s->object_size; c->inuse = max(c->inuse, ALIGN(size, sizeof(void *))); } @@ -5591,7 +5562,8 @@ static ssize_t slab_attr_store(struct kobject *kobj, * directly either failed or succeeded, in which case we loop * through the descendants with best-effort propagation. */ - for_each_memcg_cache(c, s) + c = memcg_cache(s); + if (c) attribute->store(c, buf, len); mutex_unlock(&slab_mutex); } |