[PATCH v2 14/21] mm/slab: move memcg related functions from slab.h to slub.c

Vlastimil Babka
2023-11-20T18:34:44Z

We don't share those between SLAB and SLUB anymore, so most memcg
related functions can be moved to slub.c proper.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
mm/slab.h | 206 --------------------------------------------------------------
mm/slub.c | 205 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 205 insertions(+), 206 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index 65ebf86b3fe9..a81ef7c9282d 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -486,12 +486,6 @@ void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
ssize_t slabinfo_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos);

-static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
-{
- return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
- NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
-}
-
#ifdef CONFIG_SLUB_DEBUG
#ifdef CONFIG_SLUB_DEBUG_ON
DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
@@ -551,220 +545,20 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
gfp_t gfp, bool new_slab);
void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
enum node_stat_item idx, int nr);
-
-static inline void memcg_free_slab_cgroups(struct slab *slab)
-{
- kfree(slab_objcgs(slab));
- slab->memcg_data = 0;
-}
-
-static inline size_t obj_full_size(struct kmem_cache *s)
-{
- /*
- * For each accounted object there is an extra space which is used
- * to store obj_cgroup membership. Charge it too.
- */
- return s->size + sizeof(struct obj_cgroup *);
-}
-
-/*
- * Returns false if the allocation should fail.
- */
-static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
- struct list_lru *lru,
- struct obj_cgroup **objcgp,
- size_t objects, gfp_t flags)
-{
- struct obj_cgroup *objcg;
-
- if (!memcg_kmem_online())
- return true;
-
- if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
- return true;
-
- /*
- * The obtained objcg pointer is safe to use within the current scope,
- * defined by current task or set_active_memcg() pair.
- * obj_cgroup_get() is used to get a permanent reference.
- */
- objcg = current_obj_cgroup();
- if (!objcg)
- return true;
-
- if (lru) {
- int ret;
- struct mem_cgroup *memcg;
-
- memcg = get_mem_cgroup_from_objcg(objcg);
- ret = memcg_list_lru_alloc(memcg, lru, flags);
- css_put(&memcg->css);
-
- if (ret)
- return false;
- }
-
- if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
- return false;
-
- *objcgp = objcg;
- return true;
-}
-
-static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
- struct obj_cgroup *objcg,
- gfp_t flags, size_t size,
- void **p)
-{
- struct slab *slab;
- unsigned long off;
- size_t i;
-
- if (!memcg_kmem_online() || !objcg)
- return;
-
- for (i = 0; i < size; i++) {
- if (likely(p[i])) {
- slab = virt_to_slab(p[i]);
-
- if (!slab_objcgs(slab) &&
- memcg_alloc_slab_cgroups(slab, s, flags,
- false)) {
- obj_cgroup_uncharge(objcg, obj_full_size(s));
- continue;
- }
-
- off = obj_to_index(s, slab, p[i]);
- obj_cgroup_get(objcg);
- slab_objcgs(slab)[off] = objcg;
- mod_objcg_state(objcg, slab_pgdat(slab),
- cache_vmstat_idx(s), obj_full_size(s));
- } else {
- obj_cgroup_uncharge(objcg, obj_full_size(s));
- }
- }
-}
-
-static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
- void **p, int objects)
-{
- struct obj_cgroup **objcgs;
- int i;
-
- if (!memcg_kmem_online())
- return;
-
- objcgs = slab_objcgs(slab);
- if (!objcgs)
- return;
-
- for (i = 0; i < objects; i++) {
- struct obj_cgroup *objcg;
- unsigned int off;
-
- off = obj_to_index(s, slab, p[i]);
- objcg = objcgs[off];
- if (!objcg)
- continue;
-
- objcgs[off] = NULL;
- obj_cgroup_uncharge(objcg, obj_full_size(s));
- mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
- -obj_full_size(s));
- obj_cgroup_put(objcg);
- }
-}
-
#else /* CONFIG_MEMCG_KMEM */
static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
{
return NULL;
}

-static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
-{
- return NULL;
-}
-
static inline int memcg_alloc_slab_cgroups(struct slab *slab,
struct kmem_cache *s, gfp_t gfp,
bool new_slab)
{
return 0;
}
-
-static inline void memcg_free_slab_cgroups(struct slab *slab)
-{
-}
-
-static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
- struct list_lru *lru,
- struct obj_cgroup **objcgp,
- size_t objects, gfp_t flags)
-{
- return true;
-}
-
-static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
- struct obj_cgroup *objcg,
- gfp_t flags, size_t size,
- void **p)
-{
-}
-
-static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
- void **p, int objects)
-{
-}
#endif /* CONFIG_MEMCG_KMEM */

-static inline struct kmem_cache *virt_to_cache(const void *obj)
-{
- struct slab *slab;
-
- slab = virt_to_slab(obj);
- if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
- __func__))
- return NULL;
- return slab->slab_cache;
-}
-
-static __always_inline void account_slab(struct slab *slab, int order,
- struct kmem_cache *s, gfp_t gfp)
-{
- if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
- memcg_alloc_slab_cgroups(slab, s, gfp, true);
-
- mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
- PAGE_SIZE << order);
-}
-
-static __always_inline void unaccount_slab(struct slab *slab, int order,
- struct kmem_cache *s)
-{
- if (memcg_kmem_online())
- memcg_free_slab_cgroups(slab);
-
- mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
- -(PAGE_SIZE << order));
-}
-
-static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
-{
- struct kmem_cache *cachep;
-
- if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
- !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
- return s;
-
- cachep = virt_to_cache(x);
- if (WARN(cachep && cachep != s,
- "%s: Wrong slab cache. %s but object is from %s\n",
- __func__, s->name, cachep->name))
- print_tracking(cachep, x);
- return cachep;
-}
-
void free_large_kmalloc(struct folio *folio, void *object);

size_t __ksize(const void *objp);
diff --git a/mm/slub.c b/mm/slub.c
index 9eb6508152c2..844e0beb84ee 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1814,6 +1814,165 @@ static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
#endif
#endif /* CONFIG_SLUB_DEBUG */

+static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
+{
+ return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+ NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
+}
+
+#ifdef CONFIG_MEMCG_KMEM
+static inline void memcg_free_slab_cgroups(struct slab *slab)
+{
+ kfree(slab_objcgs(slab));
+ slab->memcg_data = 0;
+}
+
+static inline size_t obj_full_size(struct kmem_cache *s)
+{
+ /*
+ * For each accounted object there is an extra space which is used
+ * to store obj_cgroup membership. Charge it too.
+ */
+ return s->size + sizeof(struct obj_cgroup *);
+}
+
+/*
+ * Returns false if the allocation should fail.
+ */
+static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
+ struct list_lru *lru,
+ struct obj_cgroup **objcgp,
+ size_t objects, gfp_t flags)
+{
+ struct obj_cgroup *objcg;
+
+ if (!memcg_kmem_online())
+ return true;
+
+ if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
+ return true;
+
+ /*
+ * The obtained objcg pointer is safe to use within the current scope,
+ * defined by current task or set_active_memcg() pair.
+ * obj_cgroup_get() is used to get a permanent reference.
+ */
+ objcg = current_obj_cgroup();
+ if (!objcg)
+ return true;
+
+ if (lru) {
+ int ret;
+ struct mem_cgroup *memcg;
+
+ memcg = get_mem_cgroup_from_objcg(objcg);
+ ret = memcg_list_lru_alloc(memcg, lru, flags);
+ css_put(&memcg->css);
+
+ if (ret)
+ return false;
+ }
+
+ if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
+ return false;
+
+ *objcgp = objcg;
+ return true;
+}
+
+static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
+ struct obj_cgroup *objcg,
+ gfp_t flags, size_t size,
+ void **p)
+{
+ struct slab *slab;
+ unsigned long off;
+ size_t i;
+
+ if (!memcg_kmem_online() || !objcg)
+ return;
+
+ for (i = 0; i < size; i++) {
+ if (likely(p[i])) {
+ slab = virt_to_slab(p[i]);
+
+ if (!slab_objcgs(slab) &&
+ memcg_alloc_slab_cgroups(slab, s, flags, false)) {
+ obj_cgroup_uncharge(objcg, obj_full_size(s));
+ continue;
+ }
+
+ off = obj_to_index(s, slab, p[i]);
+ obj_cgroup_get(objcg);
+ slab_objcgs(slab)[off] = objcg;
+ mod_objcg_state(objcg, slab_pgdat(slab),
+ cache_vmstat_idx(s), obj_full_size(s));
+ } else {
+ obj_cgroup_uncharge(objcg, obj_full_size(s));
+ }
+ }
+}
+
+static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
+ void **p, int objects)
+{
+ struct obj_cgroup **objcgs;
+ int i;
+
+ if (!memcg_kmem_online())
+ return;
+
+ objcgs = slab_objcgs(slab);
+ if (!objcgs)
+ return;
+
+ for (i = 0; i < objects; i++) {
+ struct obj_cgroup *objcg;
+ unsigned int off;
+
+ off = obj_to_index(s, slab, p[i]);
+ objcg = objcgs[off];
+ if (!objcg)
+ continue;
+
+ objcgs[off] = NULL;
+ obj_cgroup_uncharge(objcg, obj_full_size(s));
+ mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
+ -obj_full_size(s));
+ obj_cgroup_put(objcg);
+ }
+}
+#else /* CONFIG_MEMCG_KMEM */
+static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
+{
+ return NULL;
+}
+
+static inline void memcg_free_slab_cgroups(struct slab *slab)
+{
+}
+
+static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
+ struct list_lru *lru,
+ struct obj_cgroup **objcgp,
+ size_t objects, gfp_t flags)
+{
+ return true;
+}
+
+static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
+ struct obj_cgroup *objcg,
+ gfp_t flags, size_t size,
+ void **p)
+{
+}
+
+static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
+ void **p, int objects)
+{
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
/*
* Hooks for other subsystems that check memory allocations. In a typical
* production configuration these hooks all should produce no code at all.
@@ -2048,6 +2207,26 @@ static inline bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
}
#endif /* CONFIG_SLAB_FREELIST_RANDOM */

+static __always_inline void account_slab(struct slab *slab, int order,
+ struct kmem_cache *s, gfp_t gfp)
+{
+ if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
+ memcg_alloc_slab_cgroups(slab, s, gfp, true);
+
+ mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
+ PAGE_SIZE << order);
+}
+
+static __always_inline void unaccount_slab(struct slab *slab, int order,
+ struct kmem_cache *s)
+{
+ if (memcg_kmem_online())
+ memcg_free_slab_cgroups(slab);
+
+ mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
+ -(PAGE_SIZE << order));
+}
+
static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
{
struct slab *slab;
@@ -3965,6 +4144,32 @@ void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr)
}
#endif

+static inline struct kmem_cache *virt_to_cache(const void *obj)
+{
+ struct slab *slab;
+
+ slab = virt_to_slab(obj);
+ if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", __func__))
+ return NULL;
+ return slab->slab_cache;
+}
+
+static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
+{
+ struct kmem_cache *cachep;
+
+ if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
+ !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
+ return s;
+
+ cachep = virt_to_cache(x);
+ if (WARN(cachep && cachep != s,
+ "%s: Wrong slab cache. %s but object is from %s\n",
+ __func__, s->name, cachep->name))
+ print_tracking(cachep, x);
+ return cachep;
+}
+
void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller)
{
slab_free(s, virt_to_slab(x), x, NULL, &x, 1, caller);

--
2.42.1