Current names are rather confusing. Let's try to improve them.
Brief change log:
** old name ** ** new name **
kmem_cache_create_memcg kmem_cache_request_memcg_copy
memcg_kmem_create_cache memcg_copy_kmem_cache
memcg_kmem_destroy_cache memcg_destroy_kmem_cache_copy
__kmem_cache_destroy_memcg_children __kmem_cache_destroy_memcg_copies
kmem_cache_destroy_memcg_children kmem_cache_destroy_memcg_copies
mem_cgroup_destroy_all_caches memcg_destroy_kmem_cache_copies
create_work memcg_kmem_cache_copy_work
memcg_create_cache_work_func memcg_kmem_cache_copy_work_func
memcg_create_cache_enqueue memcg_schedule_kmem_cache_copy
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 2 +-
include/linux/slab.h | 6 +--
mm/memcontrol.c | 90 +++++++++++++++++++++++++-------------------
mm/slab_common.c | 29 +++++++-------
4 files changed, 69 insertions(+), 58 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3aee79fc7876..b20f533a92ca 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -498,7 +498,7 @@ __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp);
int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order);
void __memcg_uncharge_slab(struct kmem_cache *cachep, int order);
-int __kmem_cache_destroy_memcg_children(struct kmem_cache *s);
+int __kmem_cache_destroy_memcg_copies(struct kmem_cache *cachep);
/**
* memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed.
diff --git a/include/linux/slab.h b/include/linux/slab.h
index d041539b2bfb..ecb26a4547fe 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -116,9 +116,9 @@ struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
unsigned long,
void (*)(void *));
#ifdef CONFIG_MEMCG_KMEM
-struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *,
- struct kmem_cache *,
- const char *);
+struct kmem_cache *kmem_cache_request_memcg_copy(struct kmem_cache *,
+ struct mem_cgroup *,
+ const char *);
int kmem_cache_init_memcg_array(struct kmem_cache *, int);
int kmem_cache_memcg_arrays_grow(int);
#endif
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 415c81c2710a..c795c3e388dc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3099,8 +3099,12 @@ static int memcg_prepare_kmem_cache(struct kmem_cache *cachep)
return ret;
}
-static void memcg_kmem_create_cache(struct mem_cgroup *memcg,
- struct kmem_cache *root_cache)
+/*
+ * Creates a copy of the given kmem cache to be used for fulfilling allocation
+ * requests coming from the memcg to the cache.
+ */
+static void memcg_copy_kmem_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *root_cache)
{
static char memcg_name[NAME_MAX + 1];
struct kmem_cache *cachep;
@@ -3119,7 +3123,7 @@ static void memcg_kmem_create_cache(struct mem_cgroup *memcg,
return;
cgroup_name(memcg->css.cgroup, memcg_name, NAME_MAX + 1);
- cachep = kmem_cache_create_memcg(memcg, root_cache, memcg_name);
+ cachep = kmem_cache_request_memcg_copy(root_cache, memcg, memcg_name);
/*
* If we could not create a memcg cache, do not complain, because
* that's not critical at all as we can always proceed with the root
@@ -3142,7 +3146,8 @@ static void memcg_kmem_create_cache(struct mem_cgroup *memcg,
root_cache->memcg_params->memcg_caches[id] = cachep;
}
-static int memcg_kmem_destroy_cache(struct kmem_cache *cachep)
+/* Attempts to destroy a per memcg kmem cache copy. Returns 0 on success. */
+static int memcg_destroy_kmem_cache_copy(struct kmem_cache *cachep)
{
struct kmem_cache *root_cache;
struct mem_cgroup *memcg;
@@ -3208,25 +3213,39 @@ static inline void memcg_resume_kmem_account(void)
current->memcg_kmem_skip_account--;
}
-int __kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+/*
+ * Attempts to destroy all per memcg copies of the given kmem cache. Called on
+ * kmem cache destruction. Returns 0 on success.
+ */
+int __kmem_cache_destroy_memcg_copies(struct kmem_cache *cachep)
{
struct kmem_cache *c;
- int i, failed = 0;
+ int i;
+ int ret = 0;
+
+ BUG_ON(!is_root_cache(cachep));
mutex_lock(&memcg_slab_mutex);
for_each_memcg_cache_index(i) {
- c = cache_from_memcg_idx(s, i);
+ c = cache_from_memcg_idx(cachep, i);
if (!c)
continue;
- if (memcg_kmem_destroy_cache(c) != 0)
- failed++;
+ if (memcg_destroy_kmem_cache_copy(c) != 0)
+ ret = -EBUSY;
}
mutex_unlock(&memcg_slab_mutex);
- return failed;
+ return ret;
}
-static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+/*
+ * Attempts to destroy all kmem cache copies corresponding to the given memcg.
+ * Called on css offline.
+ *
+ * XXX: Caches that still have objects on css offline will be leaked. Need to
+ * reparent them instead.
+ */
+static void memcg_destroy_kmem_cache_copies(struct mem_cgroup *memcg)
{
struct kmem_cache *cachep;
struct memcg_cache_params *params, *tmp;
@@ -3239,20 +3258,21 @@ static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
cachep = memcg_params_to_cache(params);
kmem_cache_shrink(cachep);
if (atomic_read(&cachep->memcg_params->nr_pages) == 0)
- memcg_kmem_destroy_cache(cachep);
+ memcg_destroy_kmem_cache_copy(cachep);
}
mutex_unlock(&memcg_slab_mutex);
}
-struct create_work {
+struct memcg_kmem_cache_copy_work {
struct mem_cgroup *memcg;
struct kmem_cache *cachep;
struct work_struct work;
};
-static void memcg_create_cache_work_func(struct work_struct *w)
+static void memcg_kmem_cache_copy_work_func(struct work_struct *w)
{
- struct create_work *cw = container_of(w, struct create_work, work);
+ struct memcg_kmem_cache_copy_work *cw = container_of(w,
+ struct memcg_kmem_cache_copy_work, work);
struct mem_cgroup *memcg = cw->memcg;
struct kmem_cache *cachep = cw->cachep;
@@ -3260,22 +3280,19 @@ static void memcg_create_cache_work_func(struct work_struct *w)
goto out;
mutex_lock(&memcg_slab_mutex);
- memcg_kmem_create_cache(memcg, cachep);
+ memcg_copy_kmem_cache(memcg, cachep);
mutex_unlock(&memcg_slab_mutex);
out:
css_put(&memcg->css);
kfree(cw);
}
-/*
- * Enqueue the creation of a per-memcg kmem_cache.
- */
-static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg,
- struct kmem_cache *cachep)
+static void __memcg_schedule_kmem_cache_copy(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
{
- struct create_work *cw;
+ struct memcg_kmem_cache_copy_work *cw;
- cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT);
+ cw = kmalloc(sizeof(*cw), GFP_NOWAIT);
if (cw == NULL) {
css_put(&memcg->css);
return;
@@ -3283,18 +3300,18 @@ static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg,
cw->memcg = memcg;
cw->cachep = cachep;
+ INIT_WORK(&cw->work, memcg_kmem_cache_copy_work_func);
- INIT_WORK(&cw->work, memcg_create_cache_work_func);
schedule_work(&cw->work);
}
-static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
- struct kmem_cache *cachep)
+static void memcg_schedule_kmem_cache_copy(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep)
{
/*
* We need to stop accounting when we kmalloc, because if the
* corresponding kmalloc cache is not yet created, the first allocation
- * in __memcg_create_cache_enqueue will recurse.
+ * in __memcg_schedule_kmem_cache_copy will recurse.
*
* However, it is better to enclose the whole function. Depending on
* the debugging options enabled, INIT_WORK(), for instance, can
@@ -3303,7 +3320,7 @@ static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
* the safest choice is to do it like this, wrapping the whole function.
*/
memcg_stop_kmem_account();
- __memcg_create_cache_enqueue(memcg, cachep);
+ __memcg_schedule_kmem_cache_copy(memcg, cachep);
memcg_resume_kmem_account();
}
@@ -3367,22 +3384,17 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep,
/*
* If we are in a safe context (can wait, and not in interrupt
- * context), we could be be predictable and return right away.
+ * context), we could be predictable and return right away.
* This would guarantee that the allocation being performed
* already belongs in the new cache.
*
* However, there are some clashes that can arrive from locking.
* For instance, because we acquire the slab_mutex while doing
- * kmem_cache_dup, this means no further allocation could happen
- * with the slab_mutex held.
- *
- * Also, because cache creation issue get_online_cpus(), this
- * creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
- * that ends up reversed during cpu hotplug. (cpuset allocates
- * a bunch of GFP_KERNEL memory during cpuup). Due to all that,
+ * kmem_cache_request_memcg_copy, this means no further
+ * allocation could happen with the slab_mutex held. So it's
* better to defer everything.
*/
- memcg_create_cache_enqueue(memcg, cachep);
+ memcg_schedule_kmem_cache_copy(memcg, cachep);
return cachep;
out:
rcu_read_unlock();
@@ -3506,7 +3518,7 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order)
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
}
#else
-static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+static inline void memcg_destroy_kmem_cache_copies(struct mem_cgroup *memcg)
{
}
#endif /* CONFIG_MEMCG_KMEM */
@@ -6341,7 +6353,7 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
css_for_each_descendant_post(iter, css)
mem_cgroup_reparent_charges(mem_cgroup_from_css(iter));
- mem_cgroup_destroy_all_caches(memcg);
+ memcg_destroy_kmem_cache_copies(memcg);
vmpressure_cleanup(&memcg->vmpressure);
}
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 055506ba6d37..36c7d32a6f97 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -302,18 +302,18 @@ EXPORT_SYMBOL(kmem_cache_create);
#ifdef CONFIG_MEMCG_KMEM
/*
- * kmem_cache_create_memcg - Create a cache for a memory cgroup.
+ * kmem_cache_request_memcg_copy - Create a cache for a memory cgroup.
+ * @cachep: The kmem cache to make a copy of.
* @memcg: The memory cgroup the new cache is for.
- * @root_cache: The parent of the new cache.
* @memcg_name: The name of the memory cgroup.
*
* This function attempts to create a kmem cache that will serve allocation
- * requests going from @memcg to @root_cache. The new cache inherits properties
+ * requests going from @memcg to @cachep. The new cache inherits properties
* from its parent.
*/
-struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *memcg,
- struct kmem_cache *root_cache,
- const char *memcg_name)
+struct kmem_cache *kmem_cache_request_memcg_copy(struct kmem_cache *cachep,
+ struct mem_cgroup *memcg,
+ const char *memcg_name)
{
struct kmem_cache *s = NULL;
char *cache_name = NULL;
@@ -329,16 +329,15 @@ struct kmem_cache *kmem_cache_create_memcg(struct mem_cgroup *memcg,
goto out_unlock;
memcg_params->memcg = memcg;
- memcg_params->root_cache = root_cache;
+ memcg_params->root_cache = cachep;
- cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
+ cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", cachep->name,
memcg_cache_id(memcg), memcg_name);
if (!cache_name)
goto out_unlock;
- s = do_kmem_cache_create(cache_name, root_cache->object_size,
- root_cache->size, root_cache->align,
- root_cache->flags, root_cache->ctor,
+ s = do_kmem_cache_create(cache_name, cachep->object_size, cachep->size,
+ cachep->align, cachep->flags, cachep->ctor,
memcg_params);
if (IS_ERR(s))
s = NULL;
@@ -356,7 +355,7 @@ out_unlock:
return s;
}
-static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+static int kmem_cache_destroy_memcg_copies(struct kmem_cache *s)
{
int rc;
@@ -365,13 +364,13 @@ static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
return 0;
mutex_unlock(&slab_mutex);
- rc = __kmem_cache_destroy_memcg_children(s);
+ rc = __kmem_cache_destroy_memcg_copies(s);
mutex_lock(&slab_mutex);
return rc;
}
#else
-static int kmem_cache_destroy_memcg_children(struct kmem_cache *s)
+static int kmem_cache_destroy_memcg_copies(struct kmem_cache *s)
{
return 0;
}
@@ -398,7 +397,7 @@ int kmem_cache_destroy(struct kmem_cache *s)
goto out_unlock;
ret = -EBUSY;
- if (kmem_cache_destroy_memcg_children(s) != 0)
+ if (kmem_cache_destroy_memcg_copies(s) != 0)
goto out_unlock;
list_del(&s->list);
--
1.7.10.4
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