mm: remove CONFIG_MEMCG_KMEM

CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab tracking is enabled. It has been default-enabled and equivalent to CONFIG_MEMCG for almost a decade. We've only grown more kernel memory accounting sites since, and there is no imaginable cgroup usecase going forward that wants to track user pages but not the multitude of user-drivable kernel allocations. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Johannes Weiner <[email protected]> Acked-by: Roman Gushchin <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Shakeel Butt <[email protected]> Acked-by: David Hildenbrand <[email protected]> Cc: Muchun Song <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
joeyli · Jul 10, 2024 · 3a3b7fe · 3a3b7fe
1 parent 6df1323
commit 3a3b7fe
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Showing 20 changed files with 59 additions and 131 deletions.
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
@@ -275,7 +275,7 @@ struct bpf_map {
 	u32 btf_value_type_id;
 	u32 btf_vmlinux_value_type_id;
 	struct btf *btf;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	struct obj_cgroup *objcg;
 #endif
 	char name[BPF_OBJ_NAME_LEN];
@@ -2252,7 +2252,7 @@ struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id);
 
 int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
 			unsigned long nr_pages, struct page **page_array);
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
 			   int node);
 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags);

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
@@ -50,7 +50,7 @@ struct list_lru_node {
 
 struct list_lru {
 	struct list_lru_node	*node;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	struct list_head	list;
 	int			shrinker_id;
 	bool			memcg_aware;

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
@@ -195,7 +195,7 @@ struct mem_cgroup {
 	/* Range enforcement for interrupt charges */
 	struct work_struct high_work;
 
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
+#ifdef CONFIG_ZSWAP
 	unsigned long zswap_max;
 
 	/*
@@ -236,7 +236,6 @@ struct mem_cgroup {
 	 */
 	unsigned long		socket_pressure;
 
-#ifdef CONFIG_MEMCG_KMEM
 	int kmemcg_id;
 	/*
 	 * memcg->objcg is wiped out as a part of the objcg repaprenting
@@ -247,7 +246,6 @@ struct mem_cgroup {
 	struct obj_cgroup	*orig_objcg;
 	/* list of inherited objcgs, protected by objcg_lock */
 	struct list_head objcg_list;
-#endif
 
 	struct memcg_vmstats_percpu __percpu *vmstats_percpu;
 
@@ -532,7 +530,6 @@ static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *ob
 	return memcg;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
 /*
  * folio_memcg_kmem - Check if the folio has the memcg_kmem flag set.
  * @folio: Pointer to the folio.
@@ -548,15 +545,6 @@ static inline bool folio_memcg_kmem(struct folio *folio)
 	return folio->memcg_data & MEMCG_DATA_KMEM;
 }
 
-
-#else
-static inline bool folio_memcg_kmem(struct folio *folio)
-{
-	return false;
-}
-
-#endif
-
 static inline bool PageMemcgKmem(struct page *page)
 {
 	return folio_memcg_kmem(page_folio(page));
@@ -1488,7 +1476,7 @@ static inline void split_page_memcg(struct page *head, int old_order, int new_or
  * if MEMCG_DATA_OBJEXTS is set.
  */
 struct slabobj_ext {
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	struct obj_cgroup *objcg;
 #endif
 #ifdef CONFIG_MEM_ALLOC_PROFILING
@@ -1663,7 +1651,7 @@ static inline void set_shrinker_bit(struct mem_cgroup *memcg,
 }
 #endif
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 bool mem_cgroup_kmem_disabled(void);
 int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
 void __memcg_kmem_uncharge_page(struct page *page, int order);
@@ -1806,9 +1794,9 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
 {
 }
 
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
 
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
+#if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP)
 bool obj_cgroup_may_zswap(struct obj_cgroup *objcg);
 void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size);
 void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size);

diff --git a/include/linux/sched.h b/include/linux/sched.h
@@ -1457,9 +1457,8 @@ struct task_struct {
 
 	/* Used by memcontrol for targeted memcg charge: */
 	struct mem_cgroup		*active_memcg;
-#endif
 
-#ifdef CONFIG_MEMCG_KMEM
+	/* Cache for current->cgroups->memcg->objcg lookups: */
 	struct obj_cgroup		*objcg;
 #endif
 

diff --git a/include/linux/slab.h b/include/linux/slab.h
@@ -41,7 +41,7 @@ enum _slab_flag_bits {
 #ifdef CONFIG_FAILSLAB
 	_SLAB_FAILSLAB,
 #endif
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	_SLAB_ACCOUNT,
 #endif
 #ifdef CONFIG_KASAN_GENERIC
@@ -171,7 +171,7 @@ enum _slab_flag_bits {
 # define SLAB_FAILSLAB		__SLAB_FLAG_UNUSED
 #endif
 /* Account to memcg */
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 # define SLAB_ACCOUNT		__SLAB_FLAG_BIT(_SLAB_ACCOUNT)
 #else
 # define SLAB_ACCOUNT		__SLAB_FLAG_UNUSED
@@ -407,7 +407,7 @@ enum kmalloc_cache_type {
 #ifndef CONFIG_ZONE_DMA
 	KMALLOC_DMA = KMALLOC_NORMAL,
 #endif
-#ifndef CONFIG_MEMCG_KMEM
+#ifndef CONFIG_MEMCG
 	KMALLOC_CGROUP = KMALLOC_NORMAL,
 #endif
 	KMALLOC_RANDOM_START = KMALLOC_NORMAL,
@@ -420,7 +420,7 @@ enum kmalloc_cache_type {
 #ifdef CONFIG_ZONE_DMA
 	KMALLOC_DMA,
 #endif
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	KMALLOC_CGROUP,
 #endif
 	NR_KMALLOC_TYPES
@@ -435,7 +435,7 @@ kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
 #define KMALLOC_NOT_NORMAL_BITS					\
 	(__GFP_RECLAIMABLE |					\
 	(IS_ENABLED(CONFIG_ZONE_DMA)   ? __GFP_DMA : 0) |	\
-	(IS_ENABLED(CONFIG_MEMCG_KMEM) ? __GFP_ACCOUNT : 0))
+	(IS_ENABLED(CONFIG_MEMCG) ? __GFP_ACCOUNT : 0))
 
 extern unsigned long random_kmalloc_seed;
 
@@ -463,7 +463,7 @@ static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags, unsigne
 	 */
 	if (IS_ENABLED(CONFIG_ZONE_DMA) && (flags & __GFP_DMA))
 		return KMALLOC_DMA;
-	if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || (flags & __GFP_RECLAIMABLE))
+	if (!IS_ENABLED(CONFIG_MEMCG) || (flags & __GFP_RECLAIMABLE))
 		return KMALLOC_RECLAIM;
 	else
 		return KMALLOC_CGROUP;

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
@@ -36,7 +36,7 @@ TRACE_EVENT(kmem_cache_alloc,
 		__entry->bytes_alloc	= s->size;
 		__entry->gfp_flags	= (__force unsigned long)gfp_flags;
 		__entry->node		= node;
-		__entry->accounted	= IS_ENABLED(CONFIG_MEMCG_KMEM) ?
+		__entry->accounted	= IS_ENABLED(CONFIG_MEMCG) ?
 					  ((gfp_flags & __GFP_ACCOUNT) ||
 					  (s->flags & SLAB_ACCOUNT)) : false;
 	),
@@ -87,7 +87,7 @@ TRACE_EVENT(kmalloc,
 		__entry->bytes_alloc,
 		show_gfp_flags(__entry->gfp_flags),
 		__entry->node,
-		(IS_ENABLED(CONFIG_MEMCG_KMEM) &&
+		(IS_ENABLED(CONFIG_MEMCG) &&
 		 (__entry->gfp_flags & (__force unsigned long)__GFP_ACCOUNT)) ? "true" : "false")
 );
 

diff --git a/init/Kconfig b/init/Kconfig
@@ -986,11 +986,6 @@ config MEMCG_V1
 
 	  San N is unsure.
 
-config MEMCG_KMEM
-	bool
-	depends on MEMCG
-	default y
-
 config BLK_CGROUP
 	bool "IO controller"
 	depends on BLOCK

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
@@ -155,12 +155,9 @@ static void *__alloc(struct bpf_mem_cache *c, int node, gfp_t flags)
 
 static struct mem_cgroup *get_memcg(const struct bpf_mem_cache *c)
 {
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (c->objcg)
 		return get_mem_cgroup_from_objcg(c->objcg);
-#endif
-
-#ifdef CONFIG_MEMCG
 	return root_mem_cgroup;
 #else
 	return NULL;
@@ -534,7 +531,7 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
 			size += LLIST_NODE_SZ; /* room for llist_node */
 		unit_size = size;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 		if (memcg_bpf_enabled())
 			objcg = get_obj_cgroup_from_current();
 #endif
@@ -556,7 +553,7 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
 	pcc = __alloc_percpu_gfp(sizeof(*cc), 8, GFP_KERNEL);
 	if (!pcc)
 		return -ENOMEM;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	objcg = get_obj_cgroup_from_current();
 #endif
 	ma->objcg = objcg;

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
@@ -385,7 +385,7 @@ void bpf_map_free_id(struct bpf_map *map)
 	spin_unlock_irqrestore(&map_idr_lock, flags);
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 static void bpf_map_save_memcg(struct bpf_map *map)
 {
 	/* Currently if a map is created by a process belonging to the root
@@ -486,7 +486,7 @@ int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
 	unsigned long i, j;
 	struct page *pg;
 	int ret = 0;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	struct mem_cgroup *memcg, *old_memcg;
 
 	memcg = bpf_map_get_memcg(map);
@@ -505,7 +505,7 @@ int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
 		break;
 	}
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	set_active_memcg(old_memcg);
 	mem_cgroup_put(memcg);
 #endif

diff --git a/mm/kfence/core.c b/mm/kfence/core.c
@@ -602,7 +602,7 @@ static unsigned long kfence_init_pool(void)
 			continue;
 
 		__folio_set_slab(slab_folio(slab));
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 		slab->obj_exts = (unsigned long)&kfence_metadata_init[i / 2 - 1].obj_exts |
 				 MEMCG_DATA_OBJEXTS;
 #endif
@@ -652,7 +652,7 @@ static unsigned long kfence_init_pool(void)
 
 		if (!i || (i % 2))
 			continue;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 		slab->obj_exts = 0;
 #endif
 		__folio_clear_slab(slab_folio(slab));
@@ -1146,7 +1146,7 @@ void __kfence_free(void *addr)
 {
 	struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr);
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	KFENCE_WARN_ON(meta->obj_exts.objcg);
 #endif
 	/*

diff --git a/mm/kfence/kfence.h b/mm/kfence/kfence.h
@@ -97,7 +97,7 @@ struct kfence_metadata {
 	struct kfence_track free_track;
 	/* For updating alloc_covered on frees. */
 	u32 alloc_stack_hash;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	struct slabobj_ext obj_exts;
 #endif
 };

diff --git a/mm/list_lru.c b/mm/list_lru.c
@@ -15,7 +15,7 @@
 #include "slab.h"
 #include "internal.h"
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 static LIST_HEAD(memcg_list_lrus);
 static DEFINE_MUTEX(list_lrus_mutex);
 
@@ -83,7 +83,7 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
 {
 	return &lru->node[nid].lru;
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
 
 bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid,
 		    struct mem_cgroup *memcg)
@@ -294,7 +294,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
 	isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
 				      nr_to_walk);
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
 		struct list_lru_memcg *mlru;
 		unsigned long index;
@@ -324,7 +324,7 @@ static void init_one_lru(struct list_lru_one *l)
 	l->nr_items = 0;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 static struct list_lru_memcg *memcg_init_list_lru_one(gfp_t gfp)
 {
 	int nid;
@@ -544,14 +544,14 @@ static inline void memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 static void memcg_destroy_list_lru(struct list_lru *lru)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
 
 int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 		    struct lock_class_key *key, struct shrinker *shrinker)
 {
 	int i;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (shrinker)
 		lru->shrinker_id = shrinker->id;
 	else
@@ -591,7 +591,7 @@ void list_lru_destroy(struct list_lru *lru)
 	kfree(lru->node);
 	lru->node = NULL;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	lru->shrinker_id = -1;
 #endif
 }

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
@@ -2756,7 +2756,7 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
 	return 0;
 }
 
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
+#ifdef CONFIG_SLUB_DEBUG
 static int mem_cgroup_slab_show(struct seq_file *m, void *p)
 {
 	/*
@@ -2863,7 +2863,7 @@ struct cftype mem_cgroup_legacy_files[] = {
 		.write = mem_cgroup_reset,
 		.read_u64 = mem_cgroup_read_u64,
 	},
-#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_SLUB_DEBUG)
+#ifdef CONFIG_SLUB_DEBUG
 	{
 		.name = "kmem.slabinfo",
 		.seq_show = mem_cgroup_slab_show,
@@ -2922,7 +2922,6 @@ struct cftype memsw_files[] = {
 	{ },	/* terminate */
 };
 
-#ifdef CONFIG_MEMCG_KMEM
 void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
 {
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
@@ -2932,7 +2931,6 @@ void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
 			page_counter_uncharge(&memcg->kmem, -nr_pages);
 	}
 }
-#endif /* CONFIG_MEMCG_KMEM */
 
 bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
 			 gfp_t gfp_mask)