From 567e9ab2e614e55feca20e8bcb54b629e9cc1a3b Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 20 Jan 2016 15:02:24 -0800 Subject: mm: memcontrol: give the kmem states more descriptive names On any given memcg, the kmem accounting feature has three separate states: not initialized, structures allocated, and actively accounting slab memory. These are represented through a combination of the kmem_acct_activated and kmem_acct_active flags, which is confusing. Convert to a kmem_state enum with the states NONE, ALLOCATED, and ONLINE. Then rename the functions to modify the state accordingly. This follows the nomenclature of css object states more closely. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Cc: Tejun Heo Acked-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 15 ++++++++----- mm/memcontrol.c | 52 ++++++++++++++++++++++------------------------ mm/slab_common.c | 4 ++-- mm/vmscan.c | 2 +- 4 files changed, 38 insertions(+), 35 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 189f04d4d2ec..54dab4d43e6d 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -152,6 +152,12 @@ struct mem_cgroup_thresholds { struct mem_cgroup_threshold_ary *spare; }; +enum memcg_kmem_state { + KMEM_NONE, + KMEM_ALLOCATED, + KMEM_ONLINE, +}; + /* * The memory controller data structure. The memory controller controls both * page cache and RSS per cgroup. We would eventually like to provide @@ -233,8 +239,7 @@ struct mem_cgroup { #if defined(CONFIG_MEMCG_KMEM) /* Index in the kmem_cache->memcg_params.memcg_caches array */ int kmemcg_id; - bool kmem_acct_activated; - bool kmem_acct_active; + enum memcg_kmem_state kmem_state; #endif int last_scanned_node; @@ -750,9 +755,9 @@ static inline bool memcg_kmem_enabled(void) return static_branch_unlikely(&memcg_kmem_enabled_key); } -static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg) +static inline bool memcg_kmem_online(struct mem_cgroup *memcg) { - return memcg->kmem_acct_active; + return memcg->kmem_state == KMEM_ONLINE; } /* @@ -850,7 +855,7 @@ static inline bool memcg_kmem_enabled(void) return false; } -static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg) +static inline bool memcg_kmem_online(struct mem_cgroup *memcg) { return false; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 71dced17b16d..24b6bded13f8 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2378,7 +2378,7 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, struct page_counter *counter; int ret; - if (!memcg_kmem_is_active(memcg)) + if (!memcg_kmem_online(memcg)) return 0; if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) @@ -2861,14 +2861,13 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, } #ifdef CONFIG_MEMCG_KMEM -static int memcg_activate_kmem(struct mem_cgroup *memcg) +static int memcg_online_kmem(struct mem_cgroup *memcg) { int err = 0; int memcg_id; BUG_ON(memcg->kmemcg_id >= 0); - BUG_ON(memcg->kmem_acct_activated); - BUG_ON(memcg->kmem_acct_active); + BUG_ON(memcg->kmem_state); /* * For simplicity, we won't allow this to be disabled. It also can't @@ -2898,14 +2897,13 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg) static_branch_inc(&memcg_kmem_enabled_key); /* - * A memory cgroup is considered kmem-active as soon as it gets + * A memory cgroup is considered kmem-online 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->kmemcg_id = memcg_id; - memcg->kmem_acct_activated = true; - memcg->kmem_acct_active = true; + memcg->kmem_state = KMEM_ONLINE; out: return err; } @@ -2917,8 +2915,8 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg, mutex_lock(&memcg_limit_mutex); /* Top-level cgroup doesn't propagate from root */ - if (!memcg_kmem_is_active(memcg)) { - ret = memcg_activate_kmem(memcg); + if (!memcg_kmem_online(memcg)) { + ret = memcg_online_kmem(memcg); if (ret) goto out; } @@ -2938,11 +2936,12 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg) mutex_lock(&memcg_limit_mutex); /* - * If the parent cgroup is not kmem-active now, it cannot be activated - * after this point, because it has at least one child already. + * If the parent cgroup is not kmem-online now, it cannot be + * onlined after this point, because it has at least one child + * already. */ - if (memcg_kmem_is_active(parent)) - ret = memcg_activate_kmem(memcg); + if (memcg_kmem_online(parent)) + ret = memcg_online_kmem(memcg); mutex_unlock(&memcg_limit_mutex); return ret; } @@ -3590,22 +3589,21 @@ static int memcg_init_kmem(struct mem_cgroup *memcg) return tcp_init_cgroup(memcg); } -static void memcg_deactivate_kmem(struct mem_cgroup *memcg) +static void memcg_offline_kmem(struct mem_cgroup *memcg) { struct cgroup_subsys_state *css; struct mem_cgroup *parent, *child; int kmemcg_id; - if (!memcg->kmem_acct_active) + if (memcg->kmem_state != KMEM_ONLINE) return; - /* - * Clear the 'active' flag before clearing memcg_caches arrays entries. - * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it - * guarantees no cache will be created for this cgroup after we are - * done (see memcg_create_kmem_cache()). + * 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_acct_active = false; + memcg->kmem_state = KMEM_ALLOCATED; memcg_deactivate_kmem_caches(memcg); @@ -3636,9 +3634,9 @@ static void memcg_deactivate_kmem(struct mem_cgroup *memcg) memcg_free_cache_id(kmemcg_id); } -static void memcg_destroy_kmem(struct mem_cgroup *memcg) +static void memcg_free_kmem(struct mem_cgroup *memcg) { - if (memcg->kmem_acct_activated) { + if (memcg->kmem_state == KMEM_ALLOCATED) { memcg_destroy_kmem_caches(memcg); static_branch_dec(&memcg_kmem_enabled_key); WARN_ON(page_counter_read(&memcg->kmem)); @@ -3651,11 +3649,11 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) return 0; } -static void memcg_deactivate_kmem(struct mem_cgroup *memcg) +static void memcg_offline_kmem(struct mem_cgroup *memcg) { } -static void memcg_destroy_kmem(struct mem_cgroup *memcg) +static void memcg_free_kmem(struct mem_cgroup *memcg) { } #endif @@ -4308,7 +4306,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) vmpressure_cleanup(&memcg->vmpressure); - memcg_deactivate_kmem(memcg); + memcg_offline_kmem(memcg); wb_memcg_offline(memcg); } @@ -4324,7 +4322,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - memcg_destroy_kmem(memcg); + memcg_free_kmem(memcg); #ifdef CONFIG_INET if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_dec(&memcg_sockets_enabled_key); diff --git a/mm/slab_common.c b/mm/slab_common.c index e016178063e1..8c262e6dc33e 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -503,10 +503,10 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, mutex_lock(&slab_mutex); /* - * The memory cgroup could have been deactivated while the cache + * The memory cgroup could have been offlined while the cache * creation work was pending. */ - if (!memcg_kmem_is_active(memcg)) + if (!memcg_kmem_online(memcg)) goto out_unlock; idx = memcg_cache_id(memcg); diff --git a/mm/vmscan.c b/mm/vmscan.c index 5ac86956ff9d..05dd182f04fd 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -411,7 +411,7 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct shrinker *shrinker; unsigned long freed = 0; - if (memcg && !memcg_kmem_is_active(memcg)) + if (memcg && !memcg_kmem_online(memcg)) return 0; if (nr_scanned == 0) -- cgit v1.2.3-58-ga151