From b47f77b5a2243768d5cb1f143ce5e6c28baa271a Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 23 Sep 2013 16:55:43 +0800 Subject: memcg: convert to use cgroup_is_descendant() This is a preparation to kill css_id. Signed-off-by: Li Zefan Acked-by: Michal Hocko Signed-off-by: Tejun Heo --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d5ff3ce13029..aa8363ef381c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1318,7 +1318,7 @@ bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, return true; if (!root_memcg->use_hierarchy || !memcg) return false; - return css_is_ancestor(&memcg->css, &root_memcg->css); + return cgroup_is_descendant(memcg->css.cgroup, root_memcg->css.cgroup); } static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, -- cgit v1.2.3 From 34c00c319ce7eddf79be0cd307acd5630addcbb8 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 23 Sep 2013 16:56:01 +0800 Subject: memcg: convert to use cgroup id Use cgroup id instead of css id. This is a preparation to kill css id. Note, as memcg treat 0 as an invalid id, while cgroup id starts with 0, we define memcg_id == cgroup_id + 1. Signed-off-by: Li Zefan Acked-by: Michal Hocko Signed-off-by: Tejun Heo --- mm/memcontrol.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index aa8363ef381c..404a13a09efa 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -488,6 +488,23 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) return (memcg == root_mem_cgroup); } +static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) +{ + /* + * The ID of the root cgroup is 0, but memcg treat 0 as an + * invalid ID, so we return (cgroup_id + 1). + */ + return memcg->css.cgroup->id + 1; +} + +static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id) +{ + struct cgroup_subsys_state *css; + + css = css_from_id(id - 1, &mem_cgroup_subsys); + return mem_cgroup_from_css(css); +} + /* Writing them here to avoid exposing memcg's inner layout */ #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM) @@ -2709,15 +2726,10 @@ static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, */ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) { - struct cgroup_subsys_state *css; - /* ID 0 is unused ID */ if (!id) return NULL; - css = css_lookup(&mem_cgroup_subsys, id); - if (!css) - return NULL; - return mem_cgroup_from_css(css); + return mem_cgroup_from_id(id); } struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) @@ -4232,7 +4244,7 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) * css_get() was called in uncharge(). */ if (do_swap_account && swapout && memcg) - swap_cgroup_record(ent, css_id(&memcg->css)); + swap_cgroup_record(ent, mem_cgroup_id(memcg)); } #endif @@ -4284,8 +4296,8 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry, { unsigned short old_id, new_id; - old_id = css_id(&from->css); - new_id = css_id(&to->css); + old_id = mem_cgroup_id(from); + new_id = mem_cgroup_id(to); if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { mem_cgroup_swap_statistics(from, false); @@ -6325,7 +6337,7 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, } /* There is a swap entry and a page doesn't exist or isn't charged */ if (ent.val && !ret && - css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) { + mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { ret = MC_TARGET_SWAP; if (target) target->ent = ent; -- cgit v1.2.3 From 4219b2da206b3787dea4950ec53ccbc203f50e5e Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 23 Sep 2013 16:56:29 +0800 Subject: memcg: fail to create cgroup if the cgroup id is too big memcg requires the cgroup id to be smaller than 65536. This is a preparation to kill css id. Signed-off-by: Li Zefan Acked-by: Michal Hocko Signed-off-by: Tejun Heo --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 404a13a09efa..c14039575608 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -488,6 +488,12 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) return (memcg == root_mem_cgroup); } +/* + * We restrict the id in the range of [1, 65535], so it can fit into + * an unsigned short. + */ +#define MEM_CGROUP_ID_MAX USHRT_MAX + static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) { /* @@ -6059,6 +6065,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css)); int error = 0; + if (css->cgroup->id > MEM_CGROUP_ID_MAX) + return -ENOSPC; + if (!parent) return 0; -- cgit v1.2.3 From b862783594847a1087cd18c8aeac5727608c3c67 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 23 Sep 2013 16:56:47 +0800 Subject: memcg: stop using css id Now memcg uses cgroup id instead of css id. Update some comments and set mem_cgroup_subsys->use_id to 0. Signed-off-by: Li Zefan Acked-by: Michal Hocko Signed-off-by: Tejun Heo --- mm/memcontrol.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c14039575608..65a46eff5c3d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -582,16 +582,11 @@ static void disarm_sock_keys(struct mem_cgroup *memcg) #ifdef CONFIG_MEMCG_KMEM /* * This will be the memcg's index in each cache's ->memcg_params->memcg_caches. - * There are two main reasons for not using the css_id for this: - * 1) 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 - * memcgs, and none but the 200th is kmem-limited, we'd have to have a - * 200 entry array for that. - * - * 2) In order not to violate the cgroup API, we would like to do all memory - * allocation in ->create(). At that point, we haven't yet allocated the - * css_id. Having a separate index prevents us from messing with the cgroup - * core for this + * 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 + * memcgs, and none but the 200th is kmem-limited, we'd have to have a + * 200 entry array for that. * * The current size of the caches array is stored in * memcg_limited_groups_array_size. It will double each time we have to @@ -606,14 +601,14 @@ int memcg_limited_groups_array_size; * cgroups is a reasonable guess. In the future, it could be a parameter or * tunable, but that is strictly not necessary. * - * MAX_SIZE should be as large as the number of css_ids. Ideally, we could get + * MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get * this constant directly from cgroup, but it is understandable that this is * better kept as an internal representation in cgroup.c. In any case, the - * css_id space is not getting any smaller, and we don't have to necessarily + * cgrp_id space is not getting any smaller, and we don't have to necessarily * increase ours as well if it increases. */ #define MEMCG_CACHES_MIN_SIZE 4 -#define MEMCG_CACHES_MAX_SIZE 65535 +#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX /* * A lot of the calls to the cache allocation functions are expected to be @@ -5984,8 +5979,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) int node; size_t size = memcg_size(); - free_css_id(&mem_cgroup_subsys, &memcg->css); - for_each_node(node) free_mem_cgroup_per_zone_info(memcg, node); @@ -6766,7 +6759,6 @@ struct cgroup_subsys mem_cgroup_subsys = { .bind = mem_cgroup_bind, .base_cftypes = mem_cgroup_files, .early_init = 0, - .use_id = 1, }; #ifdef CONFIG_MEMCG_SWAP -- cgit v1.2.3