The only reason why they live in memcontrol.c is that we get/put css
reference to the owner memory cgroup in them. However, we can do that in
memcg_{un,}register_cache. OTOH, there are several reasons to move them
to slab_common.c.
First, I think that the less public interface functions we have in
memcontrol.h the better. Since the functions I move don't depend on
memcontrol, I think it's worth making them private to slab, especially
taking into account that the arrays are defined on the slab's side too.
Second, the way how per-memcg arrays are updated looks rather awkward:
it proceeds from memcontrol.c (__memcg_activate_kmem) to slab_common.c
(memcg_update_all_caches) and back to memcontrol.c again
(memcg_update_array_size). In the following patches I move the function
relocating the arrays (memcg_update_array_size) to slab_common.c and
therefore get rid this circular call path. I think we should have the
cache allocation stuff in the same place where we have relocation,
because it's easier to follow the code then. So I move arrays alloc/free
functions to slab_common.c too.
The third point isn't obvious. I'm going to make the list_lru structure
per-memcg to allow targeted kmem reclaim. That means we will have
per-memcg arrays in list_lrus too. It turns out that it's much easier to
update these arrays in list_lru.c rather than in memcontrol.c, because
all the stuff we need is defined there. This patch makes memcg caches
arrays allocation path conform that of the upcoming list_lru.
So let's move these functions to slab_common.c and make them static.
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 14 --------------
mm/memcontrol.c | 41 ++++-------------------------------------
mm/slab_common.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 47 insertions(+), 52 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e0752d204d9e..4d17242eeff7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -440,10 +440,6 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order);
int memcg_cache_id(struct mem_cgroup *memcg);
-int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,
- struct kmem_cache *root_cache);
-void memcg_free_cache_params(struct kmem_cache *s);
-
int memcg_update_cache_size(struct kmem_cache *s, int num_groups);
void memcg_update_array_size(int num_groups);
@@ -574,16 +570,6 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
return -1;
}
-static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
- struct kmem_cache *s, struct kmem_cache *root_cache)
-{
- return 0;
-}
-
-static inline void memcg_free_cache_params(struct kmem_cache *s)
-{
-}
-
static inline struct kmem_cache *
memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 085dc6d2f876..b6bbb1e3e2ab 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2970,43 +2970,6 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
return 0;
}
-int memcg_alloc_cache_params(struct mem_cgroup *memcg, struct kmem_cache *s,
- struct kmem_cache *root_cache)
-{
- size_t size;
-
- if (!memcg_kmem_enabled())
- return 0;
-
- if (!memcg) {
- size = offsetof(struct memcg_cache_params, memcg_caches);
- size += memcg_limited_groups_array_size * sizeof(void *);
- } else
- size = sizeof(struct memcg_cache_params);
-
- s->memcg_params = kzalloc(size, GFP_KERNEL);
- if (!s->memcg_params)
- return -ENOMEM;
-
- if (memcg) {
- s->memcg_params->memcg = memcg;
- s->memcg_params->root_cache = root_cache;
- css_get(&memcg->css);
- } else
- s->memcg_params->is_root_cache = true;
-
- return 0;
-}
-
-void memcg_free_cache_params(struct kmem_cache *s)
-{
- if (!s->memcg_params)
- return;
- if (!s->memcg_params->is_root_cache)
- css_put(&s->memcg_params->memcg->css);
- kfree(s->memcg_params);
-}
-
static void memcg_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *root_cache)
{
@@ -3037,6 +3000,7 @@ static void memcg_register_cache(struct mem_cgroup *memcg,
if (!cachep)
return;
+ css_get(&memcg->css);
list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches);
/*
@@ -3070,6 +3034,9 @@ static void memcg_unregister_cache(struct kmem_cache *cachep)
list_del(&cachep->memcg_params->list);
kmem_cache_destroy(cachep);
+
+ /* drop the reference taken in memcg_register_cache */
+ css_put(&memcg->css);
}
/*
diff --git a/mm/slab_common.c b/mm/slab_common.c
index d7d8ffd0c306..9c29ba792368 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -88,6 +88,38 @@ static inline int kmem_cache_sanity_check(const char *name, size_t size)
#endif
#ifdef CONFIG_MEMCG_KMEM
+static int memcg_alloc_cache_params(struct mem_cgroup *memcg,
+ struct kmem_cache *s, struct kmem_cache *root_cache)
+{
+ size_t size;
+
+ if (!memcg_kmem_enabled())
+ return 0;
+
+ if (!memcg) {
+ size = offsetof(struct memcg_cache_params, memcg_caches);
+ size += memcg_limited_groups_array_size * sizeof(void *);
+ } else
+ size = sizeof(struct memcg_cache_params);
+
+ s->memcg_params = kzalloc(size, GFP_KERNEL);
+ if (!s->memcg_params)
+ return -ENOMEM;
+
+ if (memcg) {
+ s->memcg_params->memcg = memcg;
+ s->memcg_params->root_cache = root_cache;
+ } else
+ s->memcg_params->is_root_cache = true;
+
+ return 0;
+}
+
+static void memcg_free_cache_params(struct kmem_cache *s)
+{
+ kfree(s->memcg_params);
+}
+
int memcg_update_all_caches(int num_memcgs)
{
struct kmem_cache *s;
@@ -113,7 +145,17 @@ out:
mutex_unlock(&slab_mutex);
return ret;
}
-#endif
+#else
+static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
+ struct kmem_cache *s, struct kmem_cache *root_cache)
+{
+ return 0;
+}
+
+static inline void memcg_free_cache_params(struct kmem_cache *s)
+{
+}
+#endif /* CONFIG_MEMCG_KMEM */
/*
* Figure out what the alignment of the objects will be given a set of
--
1.7.10.4
--
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