Subject: [to-be-updated] memcglist_lru-duplicate-lrus-upon-kmemcg-creation.patch removed from -mm tree To: glommer@xxxxxxxxxx,dchinner@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Thu, 06 Jun 2013 12:35:11 -0700 The patch titled Subject: memcg,list_lru: duplicate LRUs upon kmemcg creation has been removed from the -mm tree. Its filename was memcglist_lru-duplicate-lrus-upon-kmemcg-creation.patch This patch was dropped because an updated version will be merged ------------------------------------------------------ From: Glauber Costa <glommer@xxxxxxxxxx> Subject: memcg,list_lru: duplicate LRUs upon kmemcg creation When a new memcg is created, we need to open up room for its descriptors in all of the list_lrus that are marked per-memcg. The process is quite similar to the one we are using for the kmem caches: we initialize the new structures in an array indexed by kmemcg_id, and grow the array if needed. Key data like the size of the array will be shared between the kmem cache code and the list_lru code (they basically describe the same thing) Cc: Glauber Costa <glommer@xxxxxxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/list_lru.h | 48 ++++++++++- include/linux/memcontrol.h | 12 ++ lib/list_lru.c | 102 +++++++++++++++++++++-- mm/memcontrol.c | 151 +++++++++++++++++++++++++++++++++-- mm/slab_common.c | 1 5 files changed, 297 insertions(+), 17 deletions(-) diff -puN include/linux/list_lru.h~memcglist_lru-duplicate-lrus-upon-kmemcg-creation include/linux/list_lru.h --- a/include/linux/list_lru.h~memcglist_lru-duplicate-lrus-upon-kmemcg-creation +++ a/include/linux/list_lru.h @@ -24,6 +24,23 @@ struct list_lru_node { long nr_items; } ____cacheline_aligned_in_smp; +/* + * This is supposed to be M x N matrix, where M is kmem-limited memcg, and N is + * the number of nodes. Both dimensions are likely to be very small, but are + * potentially very big. Therefore we will allocate or grow them dynamically. + * + * The size of M will increase as new memcgs appear and can be 0 if no memcgs + * are being used. This is done in mm/memcontrol.c in a way quite similar than + * the way we use for the slab cache management. + * + * The size o N can't be determined at compile time, but won't increase once we + * determine it. It is nr_node_ids, the firmware-provided maximum number of + * nodes in a system. + */ +struct list_lru_array { + struct list_lru_node node[1]; +}; + struct list_lru { /* * Because we use a fixed-size array, this struct can be very big if @@ -37,9 +54,38 @@ struct list_lru { */ struct list_lru_node node[MAX_NUMNODES]; nodemask_t active_nodes; +#ifdef CONFIG_MEMCG_KMEM + /* All memcg-aware LRUs will be chained in the lrus list */ + struct list_head lrus; + /* M x N matrix as described above */ + struct list_lru_array **memcg_lrus; +#endif }; -int list_lru_init(struct list_lru *lru); +struct mem_cgroup; +#ifdef CONFIG_MEMCG_KMEM +struct list_lru_array *lru_alloc_array(void); +int memcg_update_all_lrus(unsigned long num); +void memcg_destroy_all_lrus(struct mem_cgroup *memcg); +void list_lru_destroy(struct list_lru *lru); +int __memcg_init_lru(struct list_lru *lru); +#else +static inline void list_lru_destroy(struct list_lru *lru) +{ +} +#endif + +int __list_lru_init(struct list_lru *lru, bool memcg_enabled); +static inline int list_lru_init(struct list_lru *lru) +{ + return __list_lru_init(lru, false); +} + +static inline int list_lru_init_memcg(struct list_lru *lru) +{ + return __list_lru_init(lru, true); +} + int list_lru_add(struct list_lru *lru, struct list_head *item); int list_lru_del(struct list_lru *lru, struct list_head *item); diff -puN include/linux/memcontrol.h~memcglist_lru-duplicate-lrus-upon-kmemcg-creation include/linux/memcontrol.h --- a/include/linux/memcontrol.h~memcglist_lru-duplicate-lrus-upon-kmemcg-creation +++ a/include/linux/memcontrol.h @@ -23,6 +23,7 @@ #include <linux/vm_event_item.h> #include <linux/hardirq.h> #include <linux/jump_label.h> +#include <linux/list_lru.h> struct mem_cgroup; struct page_cgroup; @@ -470,6 +471,12 @@ void memcg_update_array_size(int num_gro struct kmem_cache * __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp); +int memcg_new_lru(struct list_lru *lru); +int memcg_init_lru(struct list_lru *lru); + +int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups, + bool new_lru); + void mem_cgroup_destroy_cache(struct kmem_cache *cachep); void kmem_cache_destroy_memcg_children(struct kmem_cache *s); @@ -633,6 +640,11 @@ memcg_kmem_get_cache(struct kmem_cache * static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s) { } + +static inline int memcg_init_lru(struct list_lru *lru) +{ + return 0; +} #endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ diff -puN lib/list_lru.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation lib/list_lru.c --- a/lib/list_lru.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation +++ a/lib/list_lru.c @@ -2,12 +2,17 @@ * Copyright (c) 2010-2012 Red Hat, Inc. All rights reserved. * Author: David Chinner * + * Memcg Awareness + * Copyright (C) 2013 Parallels Inc. + * Author: Glauber Costa + * * Generic LRU infrastructure */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/list_lru.h> +#include <linux/memcontrol.h> int list_lru_add( @@ -163,18 +168,97 @@ list_lru_dispose_all( return total; } -int -list_lru_init( - struct list_lru *lru) +/* + * This protects the list of all LRU in the system. One only needs + * to take when registering an LRU, or when duplicating the list of lrus. + * Transversing an LRU can and should be done outside the lock + */ +static DEFINE_MUTEX(all_memcg_lrus_mutex); +static LIST_HEAD(all_memcg_lrus); + +static void list_lru_init_one(struct list_lru_node *lru) { + spin_lock_init(&lru->lock); + INIT_LIST_HEAD(&lru->list); + lru->nr_items = 0; +} + +struct list_lru_array *lru_alloc_array(void) +{ + struct list_lru_array *lru_array; int i; - nodes_clear(lru->active_nodes); - for (i = 0; i < MAX_NUMNODES; i++) { - spin_lock_init(&lru->node[i].lock); - INIT_LIST_HEAD(&lru->node[i].list); - lru->node[i].nr_items = 0; + lru_array = kzalloc(nr_node_ids * sizeof(struct list_lru_node), + GFP_KERNEL); + if (!lru_array) + return NULL; + + for (i = 0; i < nr_node_ids; i++) + list_lru_init_one(&lru_array->node[i]); + + return lru_array; +} + +#ifdef CONFIG_MEMCG_KMEM +int __memcg_init_lru(struct list_lru *lru) +{ + int ret; + + INIT_LIST_HEAD(&lru->lrus); + mutex_lock(&all_memcg_lrus_mutex); + list_add(&lru->lrus, &all_memcg_lrus); + ret = memcg_new_lru(lru); + mutex_unlock(&all_memcg_lrus_mutex); + return ret; +} + +int memcg_update_all_lrus(unsigned long num) +{ + int ret = 0; + struct list_lru *lru; + + mutex_lock(&all_memcg_lrus_mutex); + list_for_each_entry(lru, &all_memcg_lrus, lrus) { + ret = memcg_kmem_update_lru_size(lru, num, false); + if (ret) + goto out; + } +out: + mutex_unlock(&all_memcg_lrus_mutex); + return ret; +} + +void list_lru_destroy(struct list_lru *lru) +{ + mutex_lock(&all_memcg_lrus_mutex); + list_del(&lru->lrus); + mutex_unlock(&all_memcg_lrus_mutex); +} + +void memcg_destroy_all_lrus(struct mem_cgroup *memcg) +{ + struct list_lru *lru; + mutex_lock(&all_memcg_lrus_mutex); + list_for_each_entry(lru, &all_memcg_lrus, lrus) { + kfree(lru->memcg_lrus[memcg_cache_id(memcg)]); + lru->memcg_lrus[memcg_cache_id(memcg)] = NULL; + /* everybody must beaware that this memcg is no longer valid */ + wmb(); } + mutex_unlock(&all_memcg_lrus_mutex); +} +#endif + +int __list_lru_init(struct list_lru *lru, bool memcg_enabled) +{ + int i; + + nodes_clear(lru->active_nodes); + for (i = 0; i < MAX_NUMNODES; i++) + list_lru_init_one(&lru->node[i]); + + if (memcg_enabled) + return memcg_init_lru(lru); return 0; } -EXPORT_SYMBOL_GPL(list_lru_init); +EXPORT_SYMBOL_GPL(__list_lru_init); diff -puN mm/memcontrol.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation mm/memcontrol.c --- a/mm/memcontrol.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation +++ a/mm/memcontrol.c @@ -3189,16 +3189,30 @@ int memcg_update_cache_sizes(struct mem_ memcg_kmem_set_activated(memcg); ret = memcg_update_all_caches(num+1); - if (ret) { - ida_simple_remove(&kmem_limited_groups, num); - memcg_kmem_clear_activated(memcg); - return ret; - } + if (ret) + goto out; + + /* + * We should make sure that the array size is not updated until we are + * done; otherwise we have no easy way to know whether or not we should + * grow the array. + */ + ret = memcg_update_all_lrus(num + 1); + if (ret) + goto out; memcg->kmemcg_id = num; + + memcg_update_array_size(num + 1); + INIT_LIST_HEAD(&memcg->memcg_slab_caches); mutex_init(&memcg->slab_caches_mutex); + return 0; +out: + ida_simple_remove(&kmem_limited_groups, num); + memcg_kmem_clear_activated(memcg); + return ret; } static size_t memcg_caches_array_size(int num_groups) @@ -3280,6 +3294,129 @@ int memcg_update_cache_size(struct kmem_ return 0; } +/* + * memcg_kmem_update_lru_size - fill in kmemcg info into a list_lru + * + * @lru: the lru we are operating with + * @num_groups: how many kmem-limited cgroups we have + * @new_lru: true if this is a new_lru being created, false if this + * was triggered from the memcg side + * + * Returns 0 on success, and an error code otherwise. + * + * This function can be called either when a new kmem-limited memcg appears, + * or when a new list_lru is created. The work is roughly the same in two cases, + * but in the later we never have to expand the array size. + * + * This is always protected by the all_lrus_mutex from the list_lru side. But + * a race can still exists if a new memcg becomes kmem limited at the same time + * that we are registering a new memcg. Creation is protected by the + * memcg_mutex, so the creation of a new lru have to be protected by that as + * well. + * + * The lock ordering is that the memcg_mutex needs to be acquired before the + * lru-side mutex. + */ +int memcg_kmem_update_lru_size(struct list_lru *lru, int num_groups, + bool new_lru) +{ + struct list_lru_array **new_lru_array; + struct list_lru_array *lru_array; + + lru_array = lru_alloc_array(); + if (!lru_array) + return -ENOMEM; + + /* + * When a new LRU is created, we still need to update all data for that + * LRU. The procedure for late LRUs and new memcgs are quite similar, we + * only need to make sure we get into the loop even if num_groups < + * memcg_limited_groups_array_size. + */ + if ((num_groups > memcg_limited_groups_array_size) || new_lru) { + int i; + struct list_lru_array **old_array; + size_t size = memcg_caches_array_size(num_groups); + int num_memcgs = memcg_limited_groups_array_size; + + new_lru_array = kzalloc(size * sizeof(void *), GFP_KERNEL); + if (!new_lru_array) { + kfree(lru_array); + return -ENOMEM; + } + + for (i = 0; lru->memcg_lrus && (i < num_memcgs); i++) { + if (lru->memcg_lrus && lru->memcg_lrus[i]) + continue; + new_lru_array[i] = lru->memcg_lrus[i]; + } + + old_array = lru->memcg_lrus; + lru->memcg_lrus = new_lru_array; + /* + * We don't need a barrier here because we are just copying + * information over. Anybody operating in memcg_lrus will + * either follow the new array or the old one and they contain + * exactly the same information. The new space in the end is + * always empty anyway. + */ + if (lru->memcg_lrus) + kfree(old_array); + } + + if (lru->memcg_lrus) { + lru->memcg_lrus[num_groups - 1] = lru_array; + /* + * Here we do need the barrier, because of the state transition + * implied by the assignment of the array. All users should be + * able to see it + */ + wmb(); + } + return 0; +} + +/* + * This is called with the LRU-mutex being held. + */ +int memcg_new_lru(struct list_lru *lru) +{ + struct mem_cgroup *iter; + + if (!memcg_kmem_enabled()) + return 0; + + for_each_mem_cgroup(iter) { + int ret; + int memcg_id = memcg_cache_id(iter); + if (memcg_id < 0) + continue; + + ret = memcg_kmem_update_lru_size(lru, memcg_id + 1, true); + if (ret) { + mem_cgroup_iter_break(root_mem_cgroup, iter); + return ret; + } + } + return 0; +} + +/* + * We need to call back and forth from memcg to LRU because of the lock + * ordering. This complicates the flow a little bit, but since the memcg mutex + * is held through the whole duration of memcg creation, we need to hold it + * before we hold the LRU-side mutex in the case of a new list creation as + * well. + */ +int memcg_init_lru(struct list_lru *lru) +{ + int ret; + mutex_lock(&memcg_create_mutex); + ret = __memcg_init_lru(lru); + mutex_unlock(&memcg_create_mutex); + return ret; +} + int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, struct kmem_cache *root_cache) { @@ -6089,8 +6226,10 @@ static void kmem_cgroup_destroy(struct m * possible that the charges went down to 0 between mark_dead and the * res_counter read, so in that case, we don't need the put */ - if (memcg_kmem_test_and_clear_dead(memcg)) + if (memcg_kmem_test_and_clear_dead(memcg)) { + memcg_destroy_all_lrus(memcg); mem_cgroup_put(memcg); + } } #else static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) diff -puN mm/slab_common.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation mm/slab_common.c --- a/mm/slab_common.c~memcglist_lru-duplicate-lrus-upon-kmemcg-creation +++ a/mm/slab_common.c @@ -102,7 +102,6 @@ int memcg_update_all_caches(int num_memc goto out; } - memcg_update_array_size(num_memcgs); out: mutex_unlock(&slab_mutex); return ret; _ Patches currently in -mm which might be from glommer@xxxxxxxxxx are lru-add-an-element-to-a-memcg-list.patch list_lru-per-memcg-walks.patch memcg-per-memcg-kmem-shrinking.patch memcg-scan-cache-objects-hierarchically.patch vmscan-take-at-least-one-pass-with-shrinkers.patch super-targeted-memcg-reclaim.patch memcg-move-initialization-to-memcg-creation.patch vmpressure-in-kernel-notifications.patch memcg-reap-dead-memcgs-upon-global-memory-pressure.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html