diff mbox series

[v3,1/7] mm: postpone kmem_cache memcg pointer initialization to memcg_link_cache()

Message ID 20190508202458.550808-2-guro@fb.com (mailing list archive)
State New, archived
Headers show
Series mm: reparent slab memory on cgroup removal | expand

Commit Message

Roman Gushchin May 8, 2019, 8:24 p.m. UTC 
Initialize kmem_cache->memcg_params.memcg pointer in
memcg_link_cache() rather than in init_memcg_params().

Once kmem_cache will hold a reference to the memory cgroup,
it will simplify the refcounting.

For non-root kmem_caches memcg_link_cache() is always called
before the kmem_cache becomes visible to a user, so it's safe.

Signed-off-by: Roman Gushchin <guro@fb.com>
---
 mm/slab.c        |  2 +-
 mm/slab.h        |  5 +++--
 mm/slab_common.c | 14 +++++++-------
 mm/slub.c        |  2 +-
 4 files changed, 12 insertions(+), 11 deletions(-)

Comments

Shakeel Butt May 11, 2019, 12:32 a.m. UTC | #1 
From: Roman Gushchin <guro@fb.com>
Date: Wed, May 8, 2019 at 1:30 PM
To: Andrew Morton, Shakeel Butt
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<kernel-team@fb.com>, Johannes Weiner, Michal Hocko, Rik van Riel,
Christoph Lameter, Vladimir Davydov, <cgroups@vger.kernel.org>, Roman
Gushchin

> Initialize kmem_cache->memcg_params.memcg pointer in
> memcg_link_cache() rather than in init_memcg_params().
>
> Once kmem_cache will hold a reference to the memory cgroup,
> it will simplify the refcounting.
>
> For non-root kmem_caches memcg_link_cache() is always called
> before the kmem_cache becomes visible to a user, so it's safe.
>
> Signed-off-by: Roman Gushchin <guro@fb.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>


> ---
>  mm/slab.c        |  2 +-
>  mm/slab.h        |  5 +++--
>  mm/slab_common.c | 14 +++++++-------
>  mm/slub.c        |  2 +-
>  4 files changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/mm/slab.c b/mm/slab.c
> index 2915d912e89a..f6eff59e018e 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1268,7 +1268,7 @@ void __init kmem_cache_init(void)
>                                   nr_node_ids * sizeof(struct kmem_cache_node *),
>                                   SLAB_HWCACHE_ALIGN, 0, 0);
>         list_add(&kmem_cache->list, &slab_caches);
> -       memcg_link_cache(kmem_cache);
> +       memcg_link_cache(kmem_cache, NULL);
>         slab_state = PARTIAL;
>
>         /*
> diff --git a/mm/slab.h b/mm/slab.h
> index 43ac818b8592..6a562ca72bca 100644
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -289,7 +289,7 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order,
>  }
>
>  extern void slab_init_memcg_params(struct kmem_cache *);
> -extern void memcg_link_cache(struct kmem_cache *s);
> +extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
>  extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
>                                 void (*deact_fn)(struct kmem_cache *));
>
> @@ -344,7 +344,8 @@ static inline void slab_init_memcg_params(struct kmem_cache *s)
>  {
>  }
>
> -static inline void memcg_link_cache(struct kmem_cache *s)
> +static inline void memcg_link_cache(struct kmem_cache *s,
> +                                   struct mem_cgroup *memcg)
>  {
>  }
>
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 58251ba63e4a..6e00bdf8618d 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -140,13 +140,12 @@ void slab_init_memcg_params(struct kmem_cache *s)
>  }
>
>  static int init_memcg_params(struct kmem_cache *s,
> -               struct mem_cgroup *memcg, struct kmem_cache *root_cache)
> +                            struct kmem_cache *root_cache)
>  {
>         struct memcg_cache_array *arr;
>
>         if (root_cache) {
>                 s->memcg_params.root_cache = root_cache;
> -               s->memcg_params.memcg = memcg;
>                 INIT_LIST_HEAD(&s->memcg_params.children_node);
>                 INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node);
>                 return 0;
> @@ -221,11 +220,12 @@ int memcg_update_all_caches(int num_memcgs)
>         return ret;
>  }
>
> -void memcg_link_cache(struct kmem_cache *s)
> +void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg)
>  {
>         if (is_root_cache(s)) {
>                 list_add(&s->root_caches_node, &slab_root_caches);
>         } else {
> +               s->memcg_params.memcg = memcg;
>                 list_add(&s->memcg_params.children_node,
>                          &s->memcg_params.root_cache->memcg_params.children);
>                 list_add(&s->memcg_params.kmem_caches_node,
> @@ -244,7 +244,7 @@ static void memcg_unlink_cache(struct kmem_cache *s)
>  }
>  #else
>  static inline int init_memcg_params(struct kmem_cache *s,
> -               struct mem_cgroup *memcg, struct kmem_cache *root_cache)
> +                                   struct kmem_cache *root_cache)
>  {
>         return 0;
>  }
> @@ -384,7 +384,7 @@ static struct kmem_cache *create_cache(const char *name,
>         s->useroffset = useroffset;
>         s->usersize = usersize;
>
> -       err = init_memcg_params(s, memcg, root_cache);
> +       err = init_memcg_params(s, root_cache);
>         if (err)
>                 goto out_free_cache;
>
> @@ -394,7 +394,7 @@ static struct kmem_cache *create_cache(const char *name,
>
>         s->refcount = 1;
>         list_add(&s->list, &slab_caches);
> -       memcg_link_cache(s);
> +       memcg_link_cache(s, memcg);
>  out:
>         if (err)
>                 return ERR_PTR(err);
> @@ -997,7 +997,7 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name,
>
>         create_boot_cache(s, name, size, flags, useroffset, usersize);
>         list_add(&s->list, &slab_caches);
> -       memcg_link_cache(s);
> +       memcg_link_cache(s, NULL);
>         s->refcount = 1;
>         return s;
>  }
> diff --git a/mm/slub.c b/mm/slub.c
> index 5b2e364102e1..16f7e4f5a141 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4219,7 +4219,7 @@ 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);
> +       memcg_link_cache(s, NULL);
>         return s;
>  }
>
> --
> 2.20.1
>
diff mbox series

Patch

diff --git a/mm/slab.c b/mm/slab.c
index 2915d912e89a..f6eff59e018e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1268,7 +1268,7 @@  void __init kmem_cache_init(void)
 				  nr_node_ids * sizeof(struct kmem_cache_node *),
 				  SLAB_HWCACHE_ALIGN, 0, 0);
 	list_add(&kmem_cache->list, &slab_caches);
-	memcg_link_cache(kmem_cache);
+	memcg_link_cache(kmem_cache, NULL);
 	slab_state = PARTIAL;
 
 	/*
diff --git a/mm/slab.h b/mm/slab.h
index 43ac818b8592..6a562ca72bca 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -289,7 +289,7 @@  static __always_inline void memcg_uncharge_slab(struct page *page, int order,
 }
 
 extern void slab_init_memcg_params(struct kmem_cache *);
-extern void memcg_link_cache(struct kmem_cache *s);
+extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
 extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
 				void (*deact_fn)(struct kmem_cache *));
 
@@ -344,7 +344,8 @@  static inline void slab_init_memcg_params(struct kmem_cache *s)
 {
 }
 
-static inline void memcg_link_cache(struct kmem_cache *s)
+static inline void memcg_link_cache(struct kmem_cache *s,
+				    struct mem_cgroup *memcg)
 {
 }
 
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 58251ba63e4a..6e00bdf8618d 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -140,13 +140,12 @@  void slab_init_memcg_params(struct kmem_cache *s)
 }
 
 static int init_memcg_params(struct kmem_cache *s,
-		struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+			     struct kmem_cache *root_cache)
 {
 	struct memcg_cache_array *arr;
 
 	if (root_cache) {
 		s->memcg_params.root_cache = root_cache;
-		s->memcg_params.memcg = memcg;
 		INIT_LIST_HEAD(&s->memcg_params.children_node);
 		INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node);
 		return 0;
@@ -221,11 +220,12 @@  int memcg_update_all_caches(int num_memcgs)
 	return ret;
 }
 
-void memcg_link_cache(struct kmem_cache *s)
+void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg)
 {
 	if (is_root_cache(s)) {
 		list_add(&s->root_caches_node, &slab_root_caches);
 	} else {
+		s->memcg_params.memcg = memcg;
 		list_add(&s->memcg_params.children_node,
 			 &s->memcg_params.root_cache->memcg_params.children);
 		list_add(&s->memcg_params.kmem_caches_node,
@@ -244,7 +244,7 @@  static void memcg_unlink_cache(struct kmem_cache *s)
 }
 #else
 static inline int init_memcg_params(struct kmem_cache *s,
-		struct mem_cgroup *memcg, struct kmem_cache *root_cache)
+				    struct kmem_cache *root_cache)
 {
 	return 0;
 }
@@ -384,7 +384,7 @@  static struct kmem_cache *create_cache(const char *name,
 	s->useroffset = useroffset;
 	s->usersize = usersize;
 
-	err = init_memcg_params(s, memcg, root_cache);
+	err = init_memcg_params(s, root_cache);
 	if (err)
 		goto out_free_cache;
 
@@ -394,7 +394,7 @@  static struct kmem_cache *create_cache(const char *name,
 
 	s->refcount = 1;
 	list_add(&s->list, &slab_caches);
-	memcg_link_cache(s);
+	memcg_link_cache(s, memcg);
 out:
 	if (err)
 		return ERR_PTR(err);
@@ -997,7 +997,7 @@  struct kmem_cache *__init create_kmalloc_cache(const char *name,
 
 	create_boot_cache(s, name, size, flags, useroffset, usersize);
 	list_add(&s->list, &slab_caches);
-	memcg_link_cache(s);
+	memcg_link_cache(s, NULL);
 	s->refcount = 1;
 	return s;
 }
diff --git a/mm/slub.c b/mm/slub.c
index 5b2e364102e1..16f7e4f5a141 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4219,7 +4219,7 @@  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);
+	memcg_link_cache(s, NULL);
 	return s;
 }