| Message ID | 20210127233345.339910-3-shy828301@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Make shrinker's nr_deferred memcg aware | expand |
On 1/28/21 12:33 AM, Yang Shi wrote: > The shrinker map management is not purely memcg specific, it is at the intersection > between memory cgroup and shrinkers. It's allocation and assignment of a structure, > and the only memcg bit is the map is being stored in a memcg structure. So move the > shrinker_maps handling code into vmscan.c for tighter integration with shrinker code, > and remove the "memcg_" prefix. There is no functional change. > > Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Nits below: > @@ -1581,10 +1581,10 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) > return false; > } > > -extern int memcg_expand_shrinker_maps(int new_id); > - > -extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > - int nid, int shrinker_id); > +extern int alloc_shrinker_maps(struct mem_cgroup *memcg); > +extern void free_shrinker_maps(struct mem_cgroup *memcg); > +extern void set_shrinker_bit(struct mem_cgroup *memcg, > + int nid, int shrinker_id); "extern" is unnecessary and people seem to be removing them nowadays when touching the code > /* > * We allow subsystems to populate their shrinker-related > * LRU lists before register_shrinker_prepared() is called > @@ -212,7 +338,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker) > goto unlock; > > if (id >= shrinker_nr_max) { > - if (memcg_expand_shrinker_maps(id)) { > + if (expand_shrinker_maps(id)) { > idr_remove(&shrinker_idr, id); > goto unlock; > } > @@ -601,7 +727,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, Above this is a comment about barriers in memcg_set_shrinker_bit() that should be updated. > if (ret == SHRINK_EMPTY) > ret = 0; > else > - memcg_set_shrinker_bit(memcg, nid, i); > + set_shrinker_bit(memcg, nid, i); > } > freed += ret; > >
On Thu, Jan 28, 2021 at 8:10 AM Vlastimil Babka <vbabka@suse.cz> wrote: > > On 1/28/21 12:33 AM, Yang Shi wrote: > > The shrinker map management is not purely memcg specific, it is at the intersection > > between memory cgroup and shrinkers. It's allocation and assignment of a structure, > > and the only memcg bit is the map is being stored in a memcg structure. So move the > > shrinker_maps handling code into vmscan.c for tighter integration with shrinker code, > > and remove the "memcg_" prefix. There is no functional change. > > > > Signed-off-by: Yang Shi <shy828301@gmail.com> > > Acked-by: Vlastimil Babka <vbabka@suse.cz> > > Nits below: > > > @@ -1581,10 +1581,10 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) > > return false; > > } > > > > -extern int memcg_expand_shrinker_maps(int new_id); > > - > > -extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > > - int nid, int shrinker_id); > > +extern int alloc_shrinker_maps(struct mem_cgroup *memcg); > > +extern void free_shrinker_maps(struct mem_cgroup *memcg); > > +extern void set_shrinker_bit(struct mem_cgroup *memcg, > > + int nid, int shrinker_id); > > "extern" is unnecessary and people seem to be removing them nowadays when > touching the code OK, will fix in v6. > > > /* > > * We allow subsystems to populate their shrinker-related > > * LRU lists before register_shrinker_prepared() is called > > @@ -212,7 +338,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker) > > goto unlock; > > > > if (id >= shrinker_nr_max) { > > - if (memcg_expand_shrinker_maps(id)) { > > + if (expand_shrinker_maps(id)) { > > idr_remove(&shrinker_idr, id); > > goto unlock; > > } > > @@ -601,7 +727,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, > > Above this is a comment about barriers in memcg_set_shrinker_bit() that should > be updated. Thanks for catching this. Will fix in v6. > > > if (ret == SHRINK_EMPTY) > > ret = 0; > > else > > - memcg_set_shrinker_bit(memcg, nid, i); > > + set_shrinker_bit(memcg, nid, i); > > } > > freed += ret; > > > > >
On Fri, Jan 29, 2021 at 6:34 AM Kirill Tkhai <ktkhai@virtuozzo.com> wrote: > > On 28.01.2021 02:33, Yang Shi wrote: > > The shrinker map management is not purely memcg specific, it is at the intersection > > between memory cgroup and shrinkers. It's allocation and assignment of a structure, > > and the only memcg bit is the map is being stored in a memcg structure. So move the > > shrinker_maps handling code into vmscan.c for tighter integration with shrinker code, > > and remove the "memcg_" prefix. There is no functional change. > > > > Signed-off-by: Yang Shi <shy828301@gmail.com> > > --- > > include/linux/memcontrol.h | 12 ++-- > > mm/huge_memory.c | 4 +- > > mm/list_lru.c | 6 +- > > mm/memcontrol.c | 130 +------------------------------------ > > mm/vmscan.c | 130 ++++++++++++++++++++++++++++++++++++- > > 5 files changed, 142 insertions(+), 140 deletions(-) > > > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > > index eeb0b52203e9..0ee2924991fb 100644 > > --- a/include/linux/memcontrol.h > > +++ b/include/linux/memcontrol.h > > @@ -1581,10 +1581,10 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) > > return false; > > } > > > > -extern int memcg_expand_shrinker_maps(int new_id); > > - > > -extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > > - int nid, int shrinker_id); > > +extern int alloc_shrinker_maps(struct mem_cgroup *memcg); > > +extern void free_shrinker_maps(struct mem_cgroup *memcg); > > +extern void set_shrinker_bit(struct mem_cgroup *memcg, > > + int nid, int shrinker_id); > > #else > > #define mem_cgroup_sockets_enabled 0 > > static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; > > @@ -1594,8 +1594,8 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) > > return false; > > } > > > > -static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg, > > - int nid, int shrinker_id) > > +static inline void set_shrinker_bit(struct mem_cgroup *memcg, > > + int nid, int shrinker_id) > > { > > } > > #endif > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index 9237976abe72..05190d7f32ae 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -2823,8 +2823,8 @@ void deferred_split_huge_page(struct page *page) > > ds_queue->split_queue_len++; > > #ifdef CONFIG_MEMCG > > if (memcg) > > - memcg_set_shrinker_bit(memcg, page_to_nid(page), > > - deferred_split_shrinker.id); > > + set_shrinker_bit(memcg, page_to_nid(page), > > + deferred_split_shrinker.id); > > #endif > > } > > spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); > > diff --git a/mm/list_lru.c b/mm/list_lru.c > > index fe230081690b..628030fa5f69 100644 > > --- a/mm/list_lru.c > > +++ b/mm/list_lru.c > > @@ -125,8 +125,8 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item) > > list_add_tail(item, &l->list); > > /* Set shrinker bit if the first element was added */ > > if (!l->nr_items++) > > - memcg_set_shrinker_bit(memcg, nid, > > - lru_shrinker_id(lru)); > > + set_shrinker_bit(memcg, nid, > > + lru_shrinker_id(lru)); > > nlru->nr_items++; > > spin_unlock(&nlru->lock); > > return true; > > @@ -548,7 +548,7 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid, > > > > if (src->nr_items) { > > dst->nr_items += src->nr_items; > > - memcg_set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru)); > > + set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru)); > > src->nr_items = 0; > > } > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index e2de77b5bcc2..f5c9a0d2160b 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -397,130 +397,6 @@ DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); > > EXPORT_SYMBOL(memcg_kmem_enabled_key); > > #endif > > > > -static int memcg_shrinker_map_size; > > -static DEFINE_MUTEX(memcg_shrinker_map_mutex); > > - > > -static void memcg_free_shrinker_map_rcu(struct rcu_head *head) > > -{ > > - kvfree(container_of(head, struct memcg_shrinker_map, rcu)); > > -} > > - > > -static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, > > - int size, int old_size) > > -{ > > - struct memcg_shrinker_map *new, *old; > > - int nid; > > - > > - lockdep_assert_held(&memcg_shrinker_map_mutex); > > - > > - for_each_node(nid) { > > - old = rcu_dereference_protected( > > - mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); > > - /* Not yet online memcg */ > > - if (!old) > > - return 0; > > - > > - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); > > - if (!new) > > - return -ENOMEM; > > - > > - /* Set all old bits, clear all new bits */ > > - memset(new->map, (int)0xff, old_size); > > - memset((void *)new->map + old_size, 0, size - old_size); > > - > > - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); > > - call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); > > - } > > - > > - return 0; > > -} > > - > > -static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) > > -{ > > - struct mem_cgroup_per_node *pn; > > - struct memcg_shrinker_map *map; > > - int nid; > > - > > - if (mem_cgroup_is_root(memcg)) > > - return; > > - > > - for_each_node(nid) { > > - pn = mem_cgroup_nodeinfo(memcg, nid); > > - map = rcu_dereference_protected(pn->shrinker_map, true); > > - if (map) > > - kvfree(map); > > - rcu_assign_pointer(pn->shrinker_map, NULL); > > - } > > -} > > - > > -static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) > > -{ > > - struct memcg_shrinker_map *map; > > - int nid, size, ret = 0; > > - > > - if (mem_cgroup_is_root(memcg)) > > - return 0; > > - > > - mutex_lock(&memcg_shrinker_map_mutex); > > - size = memcg_shrinker_map_size; > > - for_each_node(nid) { > > - map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); > > - if (!map) { > > - memcg_free_shrinker_maps(memcg); > > - ret = -ENOMEM; > > - break; > > - } > > - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); > > - } > > - mutex_unlock(&memcg_shrinker_map_mutex); > > - > > - return ret; > > -} > > - > > -int memcg_expand_shrinker_maps(int new_id) > > -{ > > - int size, old_size, ret = 0; > > - struct mem_cgroup *memcg; > > - > > - size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); > > - old_size = memcg_shrinker_map_size; > > - if (size <= old_size) > > - return 0; > > - > > - mutex_lock(&memcg_shrinker_map_mutex); > > - if (!root_mem_cgroup) > > - goto unlock; > > - > > - for_each_mem_cgroup(memcg) { > > - if (mem_cgroup_is_root(memcg)) > > - continue; > > - ret = memcg_expand_one_shrinker_map(memcg, size, old_size); > > - if (ret) { > > - mem_cgroup_iter_break(NULL, memcg); > > - goto unlock; > > - } > > - } > > -unlock: > > - if (!ret) > > - memcg_shrinker_map_size = size; > > - mutex_unlock(&memcg_shrinker_map_mutex); > > - return ret; > > -} > > - > > -void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) > > -{ > > - if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { > > - struct memcg_shrinker_map *map; > > - > > - rcu_read_lock(); > > - map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); > > - /* Pairs with smp mb in shrink_slab() */ > > - smp_mb__before_atomic(); > > - set_bit(shrinker_id, map->map); > > - rcu_read_unlock(); > > - } > > -} > > - > > /** > > * mem_cgroup_css_from_page - css of the memcg associated with a page > > * @page: page of interest > > @@ -5370,11 +5246,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) > > struct mem_cgroup *memcg = mem_cgroup_from_css(css); > > > > /* > > - * A memcg must be visible for memcg_expand_shrinker_maps() > > + * A memcg must be visible for expand_shrinker_maps() > > * by the time the maps are allocated. So, we allocate maps > > * here, when for_each_mem_cgroup() can't skip it. > > */ > > - if (memcg_alloc_shrinker_maps(memcg)) { > > + if (alloc_shrinker_maps(memcg)) { > > mem_cgroup_id_remove(memcg); > > return -ENOMEM; > > } > > @@ -5438,7 +5314,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) > > vmpressure_cleanup(&memcg->vmpressure); > > cancel_work_sync(&memcg->high_work); > > mem_cgroup_remove_from_trees(memcg); > > - memcg_free_shrinker_maps(memcg); > > + free_shrinker_maps(memcg); > > memcg_free_kmem(memcg); > > mem_cgroup_free(memcg); > > } > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index b512dd5e3a1c..d950cead66ca 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -185,6 +185,132 @@ static LIST_HEAD(shrinker_list); > > static DECLARE_RWSEM(shrinker_rwsem); > > > > #ifdef CONFIG_MEMCG > > + > > +static int memcg_shrinker_map_size; > > +static DEFINE_MUTEX(memcg_shrinker_map_mutex); > > + > > +static void free_shrinker_map_rcu(struct rcu_head *head) > > +{ > > + kvfree(container_of(head, struct memcg_shrinker_map, rcu)); > > +} > > + > > +static int expand_one_shrinker_map(struct mem_cgroup *memcg, > > + int size, int old_size) > > +{ > > + struct memcg_shrinker_map *new, *old; > > + int nid; > > + > > + lockdep_assert_held(&memcg_shrinker_map_mutex); > > + > > + for_each_node(nid) { > > + old = rcu_dereference_protected( > > + mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); > > + /* Not yet online memcg */ > > + if (!old) > > + return 0; > > + > > + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); > > + if (!new) > > + return -ENOMEM; > > + > > + /* Set all old bits, clear all new bits */ > > + memset(new->map, (int)0xff, old_size); > > + memset((void *)new->map + old_size, 0, size - old_size); > > + > > + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); > > + call_rcu(&old->rcu, free_shrinker_map_rcu); > > + } > > + > > + return 0; > > +} > > + > > +void free_shrinker_maps(struct mem_cgroup *memcg) > > +{ > > + struct mem_cgroup_per_node *pn; > > + struct memcg_shrinker_map *map; > > + int nid; > > + > > + if (mem_cgroup_is_root(memcg)) > > + return; > > + > > + for_each_node(nid) { > > + pn = mem_cgroup_nodeinfo(memcg, nid); > > + map = rcu_dereference_protected(pn->shrinker_map, true); > > + if (map) > > + kvfree(map); > > We should to forget about below patch and kill "if (map)" check here: > > https://lore.kernel.org/linux-mm/1611216029-34397-1-git-send-email-abaci-bugfix@linux.alibaba.com/ Aha, thanks for reminding me. I didn't notice that patch. It seems it has been in the -mm tree. Will rebase on top of that patch. > > > + rcu_assign_pointer(pn->shrinker_map, NULL); > > + } > > +} > > + > > +int alloc_shrinker_maps(struct mem_cgroup *memcg) > > +{ > > + struct memcg_shrinker_map *map; > > + int nid, size, ret = 0; > > + > > + if (mem_cgroup_is_root(memcg)) > > + return 0; > > + > > + mutex_lock(&memcg_shrinker_map_mutex); > > + size = memcg_shrinker_map_size; > > + for_each_node(nid) { > > + map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); > > + if (!map) { > > + free_shrinker_maps(memcg); > > + ret = -ENOMEM; > > + break; > > + } > > + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); > > + } > > + mutex_unlock(&memcg_shrinker_map_mutex); > > + > > + return ret; > > +} > > + > > +static int expand_shrinker_maps(int new_id) > > +{ > > + int size, old_size, ret = 0; > > + struct mem_cgroup *memcg; > > + > > + size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); > > + old_size = memcg_shrinker_map_size; > > + if (size <= old_size) > > + return 0; > > + > > + mutex_lock(&memcg_shrinker_map_mutex); > > + if (!root_mem_cgroup) > > + goto unlock; > > + > > + memcg = mem_cgroup_iter(NULL, NULL, NULL); > > + do { > > + if (mem_cgroup_is_root(memcg)) > > + continue; > > + ret = expand_one_shrinker_map(memcg, size, old_size); > > + if (ret) { > > + mem_cgroup_iter_break(NULL, memcg); > > + goto unlock; > > + } > > + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); > > +unlock: > > + if (!ret) > > + memcg_shrinker_map_size = size; > > + mutex_unlock(&memcg_shrinker_map_mutex); > > + return ret; > > +} > > + > > +void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) > > +{ > > + if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { > > + struct memcg_shrinker_map *map; > > + > > + rcu_read_lock(); > > + map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); > > + /* Pairs with smp mb in shrink_slab() */ > > + smp_mb__before_atomic(); > > + set_bit(shrinker_id, map->map); > > + rcu_read_unlock(); > > + } > > +} > > + > > /* > > * We allow subsystems to populate their shrinker-related > > * LRU lists before register_shrinker_prepared() is called > > @@ -212,7 +338,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker) > > goto unlock; > > > > if (id >= shrinker_nr_max) { > > - if (memcg_expand_shrinker_maps(id)) { > > + if (expand_shrinker_maps(id)) { > > idr_remove(&shrinker_idr, id); > > goto unlock; > > } > > @@ -601,7 +727,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, > > if (ret == SHRINK_EMPTY) > > ret = 0; > > else > > - memcg_set_shrinker_bit(memcg, nid, i); > > + set_shrinker_bit(memcg, nid, i); > > } > > freed += ret; > > > > > >
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index eeb0b52203e9..0ee2924991fb 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1581,10 +1581,10 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) return false; } -extern int memcg_expand_shrinker_maps(int new_id); - -extern void memcg_set_shrinker_bit(struct mem_cgroup *memcg, - int nid, int shrinker_id); +extern int alloc_shrinker_maps(struct mem_cgroup *memcg); +extern void free_shrinker_maps(struct mem_cgroup *memcg); +extern void set_shrinker_bit(struct mem_cgroup *memcg, + int nid, int shrinker_id); #else #define mem_cgroup_sockets_enabled 0 static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; @@ -1594,8 +1594,8 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) return false; } -static inline void memcg_set_shrinker_bit(struct mem_cgroup *memcg, - int nid, int shrinker_id) +static inline void set_shrinker_bit(struct mem_cgroup *memcg, + int nid, int shrinker_id) { } #endif diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9237976abe72..05190d7f32ae 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2823,8 +2823,8 @@ void deferred_split_huge_page(struct page *page) ds_queue->split_queue_len++; #ifdef CONFIG_MEMCG if (memcg) - memcg_set_shrinker_bit(memcg, page_to_nid(page), - deferred_split_shrinker.id); + set_shrinker_bit(memcg, page_to_nid(page), + deferred_split_shrinker.id); #endif } spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); diff --git a/mm/list_lru.c b/mm/list_lru.c index fe230081690b..628030fa5f69 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -125,8 +125,8 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item) list_add_tail(item, &l->list); /* Set shrinker bit if the first element was added */ if (!l->nr_items++) - memcg_set_shrinker_bit(memcg, nid, - lru_shrinker_id(lru)); + set_shrinker_bit(memcg, nid, + lru_shrinker_id(lru)); nlru->nr_items++; spin_unlock(&nlru->lock); return true; @@ -548,7 +548,7 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid, if (src->nr_items) { dst->nr_items += src->nr_items; - memcg_set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru)); + set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru)); src->nr_items = 0; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e2de77b5bcc2..f5c9a0d2160b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -397,130 +397,6 @@ DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); EXPORT_SYMBOL(memcg_kmem_enabled_key); #endif -static int memcg_shrinker_map_size; -static DEFINE_MUTEX(memcg_shrinker_map_mutex); - -static void memcg_free_shrinker_map_rcu(struct rcu_head *head) -{ - kvfree(container_of(head, struct memcg_shrinker_map, rcu)); -} - -static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, - int size, int old_size) -{ - struct memcg_shrinker_map *new, *old; - int nid; - - lockdep_assert_held(&memcg_shrinker_map_mutex); - - for_each_node(nid) { - old = rcu_dereference_protected( - mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); - /* Not yet online memcg */ - if (!old) - return 0; - - new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); - if (!new) - return -ENOMEM; - - /* Set all old bits, clear all new bits */ - memset(new->map, (int)0xff, old_size); - memset((void *)new->map + old_size, 0, size - old_size); - - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); - call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); - } - - return 0; -} - -static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) -{ - struct mem_cgroup_per_node *pn; - struct memcg_shrinker_map *map; - int nid; - - if (mem_cgroup_is_root(memcg)) - return; - - for_each_node(nid) { - pn = mem_cgroup_nodeinfo(memcg, nid); - map = rcu_dereference_protected(pn->shrinker_map, true); - if (map) - kvfree(map); - rcu_assign_pointer(pn->shrinker_map, NULL); - } -} - -static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) -{ - struct memcg_shrinker_map *map; - int nid, size, ret = 0; - - if (mem_cgroup_is_root(memcg)) - return 0; - - mutex_lock(&memcg_shrinker_map_mutex); - size = memcg_shrinker_map_size; - for_each_node(nid) { - map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); - if (!map) { - memcg_free_shrinker_maps(memcg); - ret = -ENOMEM; - break; - } - rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); - } - mutex_unlock(&memcg_shrinker_map_mutex); - - return ret; -} - -int memcg_expand_shrinker_maps(int new_id) -{ - int size, old_size, ret = 0; - struct mem_cgroup *memcg; - - size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); - old_size = memcg_shrinker_map_size; - if (size <= old_size) - return 0; - - mutex_lock(&memcg_shrinker_map_mutex); - if (!root_mem_cgroup) - goto unlock; - - for_each_mem_cgroup(memcg) { - if (mem_cgroup_is_root(memcg)) - continue; - ret = memcg_expand_one_shrinker_map(memcg, size, old_size); - if (ret) { - mem_cgroup_iter_break(NULL, memcg); - goto unlock; - } - } -unlock: - if (!ret) - memcg_shrinker_map_size = size; - mutex_unlock(&memcg_shrinker_map_mutex); - return ret; -} - -void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) -{ - if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { - struct memcg_shrinker_map *map; - - rcu_read_lock(); - map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); - /* Pairs with smp mb in shrink_slab() */ - smp_mb__before_atomic(); - set_bit(shrinker_id, map->map); - rcu_read_unlock(); - } -} - /** * mem_cgroup_css_from_page - css of the memcg associated with a page * @page: page of interest @@ -5370,11 +5246,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) struct mem_cgroup *memcg = mem_cgroup_from_css(css); /* - * A memcg must be visible for memcg_expand_shrinker_maps() + * A memcg must be visible for expand_shrinker_maps() * by the time the maps are allocated. So, we allocate maps * here, when for_each_mem_cgroup() can't skip it. */ - if (memcg_alloc_shrinker_maps(memcg)) { + if (alloc_shrinker_maps(memcg)) { mem_cgroup_id_remove(memcg); return -ENOMEM; } @@ -5438,7 +5314,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) vmpressure_cleanup(&memcg->vmpressure); cancel_work_sync(&memcg->high_work); mem_cgroup_remove_from_trees(memcg); - memcg_free_shrinker_maps(memcg); + free_shrinker_maps(memcg); memcg_free_kmem(memcg); mem_cgroup_free(memcg); } diff --git a/mm/vmscan.c b/mm/vmscan.c index b512dd5e3a1c..d950cead66ca 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -185,6 +185,132 @@ static LIST_HEAD(shrinker_list); static DECLARE_RWSEM(shrinker_rwsem); #ifdef CONFIG_MEMCG + +static int memcg_shrinker_map_size; +static DEFINE_MUTEX(memcg_shrinker_map_mutex); + +static void free_shrinker_map_rcu(struct rcu_head *head) +{ + kvfree(container_of(head, struct memcg_shrinker_map, rcu)); +} + +static int expand_one_shrinker_map(struct mem_cgroup *memcg, + int size, int old_size) +{ + struct memcg_shrinker_map *new, *old; + int nid; + + lockdep_assert_held(&memcg_shrinker_map_mutex); + + for_each_node(nid) { + old = rcu_dereference_protected( + mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); + /* Not yet online memcg */ + if (!old) + return 0; + + new = kvmalloc_node(sizeof(*new) + size, GFP_KERNEL, nid); + if (!new) + return -ENOMEM; + + /* Set all old bits, clear all new bits */ + memset(new->map, (int)0xff, old_size); + memset((void *)new->map + old_size, 0, size - old_size); + + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); + call_rcu(&old->rcu, free_shrinker_map_rcu); + } + + return 0; +} + +void free_shrinker_maps(struct mem_cgroup *memcg) +{ + struct mem_cgroup_per_node *pn; + struct memcg_shrinker_map *map; + int nid; + + if (mem_cgroup_is_root(memcg)) + return; + + for_each_node(nid) { + pn = mem_cgroup_nodeinfo(memcg, nid); + map = rcu_dereference_protected(pn->shrinker_map, true); + if (map) + kvfree(map); + rcu_assign_pointer(pn->shrinker_map, NULL); + } +} + +int alloc_shrinker_maps(struct mem_cgroup *memcg) +{ + struct memcg_shrinker_map *map; + int nid, size, ret = 0; + + if (mem_cgroup_is_root(memcg)) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + size = memcg_shrinker_map_size; + for_each_node(nid) { + map = kvzalloc_node(sizeof(*map) + size, GFP_KERNEL, nid); + if (!map) { + free_shrinker_maps(memcg); + ret = -ENOMEM; + break; + } + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); + } + mutex_unlock(&memcg_shrinker_map_mutex); + + return ret; +} + +static int expand_shrinker_maps(int new_id) +{ + int size, old_size, ret = 0; + struct mem_cgroup *memcg; + + size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); + old_size = memcg_shrinker_map_size; + if (size <= old_size) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + if (!root_mem_cgroup) + goto unlock; + + memcg = mem_cgroup_iter(NULL, NULL, NULL); + do { + if (mem_cgroup_is_root(memcg)) + continue; + ret = expand_one_shrinker_map(memcg, size, old_size); + if (ret) { + mem_cgroup_iter_break(NULL, memcg); + goto unlock; + } + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); +unlock: + if (!ret) + memcg_shrinker_map_size = size; + mutex_unlock(&memcg_shrinker_map_mutex); + return ret; +} + +void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) +{ + if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { + struct memcg_shrinker_map *map; + + rcu_read_lock(); + map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); + /* Pairs with smp mb in shrink_slab() */ + smp_mb__before_atomic(); + set_bit(shrinker_id, map->map); + rcu_read_unlock(); + } +} + /* * We allow subsystems to populate their shrinker-related * LRU lists before register_shrinker_prepared() is called @@ -212,7 +338,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker) goto unlock; if (id >= shrinker_nr_max) { - if (memcg_expand_shrinker_maps(id)) { + if (expand_shrinker_maps(id)) { idr_remove(&shrinker_idr, id); goto unlock; } @@ -601,7 +727,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, if (ret == SHRINK_EMPTY) ret = 0; else - memcg_set_shrinker_bit(memcg, nid, i); + set_shrinker_bit(memcg, nid, i); } freed += ret;
The shrinker map management is not purely memcg specific, it is at the intersection between memory cgroup and shrinkers. It's allocation and assignment of a structure, and the only memcg bit is the map is being stored in a memcg structure. So move the shrinker_maps handling code into vmscan.c for tighter integration with shrinker code, and remove the "memcg_" prefix. There is no functional change. Signed-off-by: Yang Shi <shy828301@gmail.com> --- include/linux/memcontrol.h | 12 ++-- mm/huge_memory.c | 4 +- mm/list_lru.c | 6 +- mm/memcontrol.c | 130 +------------------------------------ mm/vmscan.c | 130 ++++++++++++++++++++++++++++++++++++- 5 files changed, 142 insertions(+), 140 deletions(-)