From d886f4e483ce63a3304adc9eda87031b93341c28 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 20 Jan 2016 15:02:47 -0800 Subject: [PATCH] mm: memcontrol: rein in the CONFIG space madness What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory controller code is insignificant, having these conditionals is not worth the complication and fragility that comes with them. [akpm@linux-foundation.org: rework mem_cgroup_css_free() statement ordering] Signed-off-by: Johannes Weiner Cc: Michal Hocko Acked-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 14 ++++------ init/Kconfig | 21 +++------------ mm/memcontrol.c | 53 +++----------------------------------- mm/vmpressure.c | 2 -- 4 files changed, 12 insertions(+), 78 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 2bb14d021cd0..47995b499429 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -233,9 +233,11 @@ struct mem_cgroup { */ struct mem_cgroup_stat_cpu __percpu *stat; -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) + unsigned long socket_pressure; + + /* Legacy tcp memory accounting */ struct cg_proto tcp_mem; -#endif + #ifndef CONFIG_SLOB /* Index in the kmem_cache->memcg_params.memcg_caches array */ int kmemcg_id; @@ -254,10 +256,6 @@ struct mem_cgroup { struct wb_domain cgwb_domain; #endif -#ifdef CONFIG_INET - unsigned long socket_pressure; -#endif - /* List of events which userspace want to receive */ struct list_head event_list; spinlock_t event_list_lock; @@ -712,15 +710,13 @@ void sock_update_memcg(struct sock *sk); void sock_release_memcg(struct sock *sk); bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages); void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages); -#if defined(CONFIG_MEMCG) && defined(CONFIG_INET) +#ifdef CONFIG_MEMCG extern struct static_key_false memcg_sockets_enabled_key; #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key) static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) { -#ifdef CONFIG_MEMCG_LEGACY_KMEM if (memcg->tcp_mem.memory_pressure) return true; -#endif do { if (time_before(jiffies, memcg->socket_pressure)) return true; diff --git a/init/Kconfig b/init/Kconfig index a0a15cec8daf..22320804fbaf 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -964,20 +964,6 @@ config MEMCG_SWAP_ENABLED For those who want to have the feature enabled by default should select this option (if, for some reason, they need to disable it then swapaccount=0 does the trick). -config MEMCG_LEGACY_KMEM - bool -config MEMCG_KMEM - bool "Legacy Memory Resource Controller Kernel Memory accounting" - depends on MEMCG - depends on SLUB || SLAB - select MEMCG_LEGACY_KMEM - help - The Kernel Memory extension for Memory Resource Controller can limit - the amount of memory used by kernel objects in the system. Those are - fundamentally different from the entities handled by the standard - Memory Controller, which are page-based, and can be swapped. Users of - the kmem extension can use it to guarantee that no group of processes - will ever exhaust kernel resources alone. config BLK_CGROUP bool "IO controller" @@ -1190,10 +1176,9 @@ config USER_NS to provide different user info for different servers. When user namespaces are enabled in the kernel it is - recommended that the MEMCG and MEMCG_KMEM options also be - enabled and that user-space use the memory control groups to - limit the amount of memory a memory unprivileged users can - use. + recommended that the MEMCG option also be enabled and that + user-space use the memory control groups to limit the amount + of memory a memory unprivileged users can use. If unsure, say N. diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 15896708429b..379f9911b87b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2842,11 +2842,9 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, case _KMEM: counter = &memcg->kmem; break; -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) case _TCP: counter = &memcg->tcp_mem.memory_allocated; break; -#endif default: BUG(); } @@ -3006,7 +3004,6 @@ static void memcg_free_kmem(struct mem_cgroup *memcg) } #endif /* !CONFIG_SLOB */ -#ifdef CONFIG_MEMCG_LEGACY_KMEM static int memcg_update_kmem_limit(struct mem_cgroup *memcg, unsigned long limit) { @@ -3024,16 +3021,7 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg, mutex_unlock(&memcg_limit_mutex); return ret; } -#else -static int memcg_update_kmem_limit(struct mem_cgroup *memcg, - unsigned long limit) -{ - return -EINVAL; -} -#endif /* CONFIG_MEMCG_LEGACY_KMEM */ - -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit) { int ret; @@ -3068,12 +3056,6 @@ static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit) mutex_unlock(&memcg_limit_mutex); return ret; } -#else -static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit) -{ - return -EINVAL; -} -#endif /* CONFIG_MEMCG_LEGACY_KMEM && CONFIG_INET */ /* * The user of this function is... @@ -3136,11 +3118,9 @@ static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, case _KMEM: counter = &memcg->kmem; break; -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) case _TCP: counter = &memcg->tcp_mem.memory_allocated; break; -#endif default: BUG(); } @@ -4094,7 +4074,6 @@ static struct cftype mem_cgroup_legacy_files[] = { .seq_show = memcg_numa_stat_show, }, #endif -#ifdef CONFIG_MEMCG_LEGACY_KMEM { .name = "kmem.limit_in_bytes", .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), @@ -4127,7 +4106,6 @@ static struct cftype mem_cgroup_legacy_files[] = { .seq_show = memcg_slab_show, }, #endif -#ifdef CONFIG_INET { .name = "kmem.tcp.limit_in_bytes", .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), @@ -4151,8 +4129,6 @@ static struct cftype mem_cgroup_legacy_files[] = { .write = mem_cgroup_reset, .read_u64 = mem_cgroup_read_u64, }, -#endif -#endif { }, /* terminate */ }; @@ -4280,14 +4256,12 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) vmpressure_init(&memcg->vmpressure); INIT_LIST_HEAD(&memcg->event_list); spin_lock_init(&memcg->event_list_lock); + memcg->socket_pressure = jiffies; #ifndef CONFIG_SLOB memcg->kmemcg_id = -1; #endif #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&memcg->cgwb_list); -#endif -#ifdef CONFIG_INET - memcg->socket_pressure = jiffies; #endif return &memcg->css; @@ -4321,10 +4295,8 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) memcg->soft_limit = PAGE_COUNTER_MAX; page_counter_init(&memcg->memsw, &parent->memsw); page_counter_init(&memcg->kmem, &parent->kmem); -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) page_counter_init(&memcg->tcp_mem.memory_allocated, &parent->tcp_mem.memory_allocated); -#endif /* * No need to take a reference to the parent because cgroup @@ -4336,9 +4308,7 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) memcg->soft_limit = PAGE_COUNTER_MAX; page_counter_init(&memcg->memsw, NULL); page_counter_init(&memcg->kmem, NULL); -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) page_counter_init(&memcg->tcp_mem.memory_allocated, NULL); -#endif /* * Deeper hierachy with use_hierarchy == false doesn't make * much sense so let cgroup subsystem know about this @@ -4353,10 +4323,8 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css) if (ret) return ret; -#ifdef CONFIG_INET if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_inc(&memcg_sockets_enabled_key); -#endif /* * Make sure the memcg is initialized: mem_cgroup_iter() @@ -4403,18 +4371,13 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); -#ifdef CONFIG_INET if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_dec(&memcg_sockets_enabled_key); -#endif - memcg_free_kmem(memcg); - -#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET) if (memcg->tcp_mem.active) static_branch_dec(&memcg_sockets_enabled_key); -#endif + memcg_free_kmem(memcg); __mem_cgroup_free(memcg); } @@ -5613,8 +5576,6 @@ void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage) commit_charge(newpage, memcg, true); } -#ifdef CONFIG_INET - DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); EXPORT_SYMBOL(memcg_sockets_enabled_key); @@ -5640,10 +5601,8 @@ void sock_update_memcg(struct sock *sk) memcg = mem_cgroup_from_task(current); if (memcg == root_mem_cgroup) goto out; -#ifdef CONFIG_MEMCG_LEGACY_KMEM if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcp_mem.active) goto out; -#endif if (css_tryget_online(&memcg->css)) sk->sk_memcg = memcg; out: @@ -5669,7 +5628,6 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) { gfp_t gfp_mask = GFP_KERNEL; -#ifdef CONFIG_MEMCG_LEGACY_KMEM if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { struct page_counter *counter; @@ -5682,7 +5640,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) memcg->tcp_mem.memory_pressure = 1; return false; } -#endif + /* Don't block in the packet receive path */ if (in_softirq()) gfp_mask = GFP_NOWAIT; @@ -5701,19 +5659,16 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) */ void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) { -#ifdef CONFIG_MEMCG_LEGACY_KMEM if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { page_counter_uncharge(&memcg->tcp_mem.memory_allocated, nr_pages); return; } -#endif + page_counter_uncharge(&memcg->memory, nr_pages); css_put_many(&memcg->css, nr_pages); } -#endif /* CONFIG_INET */ - static int __init cgroup_memory(char *s) { char *token; diff --git a/mm/vmpressure.c b/mm/vmpressure.c index 89b1d441af4b..9a6c0704211c 100644 --- a/mm/vmpressure.c +++ b/mm/vmpressure.c @@ -275,7 +275,6 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, level = vmpressure_calc_level(scanned, reclaimed); -#ifdef CONFIG_INET if (level > VMPRESSURE_LOW) { /* * Let the socket buffer allocator know that @@ -287,7 +286,6 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, */ memcg->socket_pressure = jiffies + HZ; } -#endif } }