X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=mm%2Fslub.c;h=7f4bc7027ed53536efaaf5663f007bd2442de503;hb=edccb59429657b09806146339e2b27594c1d1da0;hp=7ec0a965c6a3a366550b2500f9880f65e5025138;hpb=ca78d3173cff3503bcd15723b049757f75762d15;p=karo-tx-linux.git

diff --git a/mm/slub.c b/mm/slub.c
index 7ec0a965c6a3..7f4bc7027ed5 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -214,11 +214,13 @@ enum track_item { TRACK_ALLOC, TRACK_FREE };
 static int sysfs_slab_add(struct kmem_cache *);
 static int sysfs_slab_alias(struct kmem_cache *, const char *);
 static void memcg_propagate_slab_attrs(struct kmem_cache *s);
+static void sysfs_slab_remove(struct kmem_cache *s);
 #else
 static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
 static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
 							{ return 0; }
 static inline void memcg_propagate_slab_attrs(struct kmem_cache *s) { }
+static inline void sysfs_slab_remove(struct kmem_cache *s) { }
 #endif
 
 static inline void stat(const struct kmem_cache *s, enum stat_item si)
@@ -1630,6 +1632,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
 		flags &= ~GFP_SLAB_BUG_MASK;
 		pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n",
 				invalid_mask, &invalid_mask, flags, &flags);
+		dump_stack();
 	}
 
 	return allocate_slab(s,
@@ -3686,6 +3689,7 @@ int __kmem_cache_shutdown(struct kmem_cache *s)
 		if (n->nr_partial || slabs_node(s, node))
 			return 1;
 	}
+	sysfs_slab_remove(s);
 	return 0;
 }
 
@@ -3952,6 +3956,42 @@ int __kmem_cache_shrink(struct kmem_cache *s)
 	return ret;
 }
 
+#ifdef CONFIG_MEMCG
+static void kmemcg_cache_deact_after_rcu(struct kmem_cache *s)
+{
+	/*
+	 * Called with all the locks held after a sched RCU grace period.
+	 * Even if @s becomes empty after shrinking, we can't know that @s
+	 * doesn't have allocations already in-flight and thus can't
+	 * destroy @s until the associated memcg is released.
+	 *
+	 * However, let's remove the sysfs files for empty caches here.
+	 * Each cache has a lot of interface files which aren't
+	 * particularly useful for empty draining caches; otherwise, we can
+	 * easily end up with millions of unnecessary sysfs files on
+	 * systems which have a lot of memory and transient cgroups.
+	 */
+	if (!__kmem_cache_shrink(s))
+		sysfs_slab_remove(s);
+}
+
+void __kmemcg_cache_deactivate(struct kmem_cache *s)
+{
+	/*
+	 * Disable empty slabs caching. Used to avoid pinning offline
+	 * memory cgroups by kmem pages that can be freed.
+	 */
+	s->cpu_partial = 0;
+	s->min_partial = 0;
+
+	/*
+	 * s->cpu_partial is checked locklessly (see put_cpu_partial), so
+	 * we have to make sure the change is visible before shrinking.
+	 */
+	slab_deactivate_memcg_cache_rcu_sched(s, kmemcg_cache_deact_after_rcu);
+}
+#endif
+
 static int slab_mem_going_offline_callback(void *arg)
 {
 	struct kmem_cache *s;
@@ -4108,6 +4148,7 @@ static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
 	}
 	slab_init_memcg_params(s);
 	list_add(&s->list, &slab_caches);
+	memcg_link_cache(s);
 	return s;
 }
 
@@ -4667,6 +4708,22 @@ enum slab_stat_type {
 #define SO_OBJECTS	(1 << SL_OBJECTS)
 #define SO_TOTAL	(1 << SL_TOTAL)
 
+#ifdef CONFIG_MEMCG
+static bool memcg_sysfs_enabled = IS_ENABLED(CONFIG_SLUB_MEMCG_SYSFS_ON);
+
+static int __init setup_slub_memcg_sysfs(char *str)
+{
+	int v;
+
+	if (get_option(&str, &v) > 0)
+		memcg_sysfs_enabled = v;
+
+	return 1;
+}
+
+__setup("slub_memcg_sysfs=", setup_slub_memcg_sysfs);
+#endif
+
 static ssize_t show_slab_objects(struct kmem_cache *s,
 			    char *buf, unsigned long flags)
 {
@@ -5570,8 +5627,14 @@ static int sysfs_slab_add(struct kmem_cache *s)
 {
 	int err;
 	const char *name;
+	struct kset *kset = cache_kset(s);
 	int unmergeable = slab_unmergeable(s);
 
+	if (!kset) {
+		kobject_init(&s->kobj, &slab_ktype);
+		return 0;
+	}
+
 	if (unmergeable) {
 		/*
 		 * Slabcache can never be merged so we can use the name proper.
@@ -5588,7 +5651,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
 		name = create_unique_id(s);
 	}
 
-	s->kobj.kset = cache_kset(s);
+	s->kobj.kset = kset;
 	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
 	if (err)
 		goto out;
@@ -5598,7 +5661,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
 		goto out_del_kobj;
 
 #ifdef CONFIG_MEMCG
-	if (is_root_cache(s)) {
+	if (is_root_cache(s) && memcg_sysfs_enabled) {
 		s->memcg_kset = kset_create_and_add("cgroup", NULL, &s->kobj);
 		if (!s->memcg_kset) {
 			err = -ENOMEM;
@@ -5621,7 +5684,7 @@ out_del_kobj:
 	goto out;
 }
 
-void sysfs_slab_remove(struct kmem_cache *s)
+static void sysfs_slab_remove(struct kmem_cache *s)
 {
 	if (slab_state < FULL)
 		/*
@@ -5630,12 +5693,26 @@ void sysfs_slab_remove(struct kmem_cache *s)
 		 */
 		return;
 
+	if (!s->kobj.state_in_sysfs)
+		/*
+		 * For a memcg cache, this may be called during
+		 * deactivation and again on shutdown.  Remove only once.
+		 * A cache is never shut down before deactivation is
+		 * complete, so no need to worry about synchronization.
+		 */
+		return;
+
 #ifdef CONFIG_MEMCG
 	kset_unregister(s->memcg_kset);
 #endif
 	kobject_uevent(&s->kobj, KOBJ_REMOVE);
 	kobject_del(&s->kobj);
-	kobject_put(&s->kobj);
+}
+
+void sysfs_slab_release(struct kmem_cache *s)
+{
+	if (slab_state >= FULL)
+		kobject_put(&s->kobj);
 }
 
 /*