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-rw-r--r--mm/memcontrol.c75
-rw-r--r--mm/page_alloc.c9
-rw-r--r--mm/slab.h16
3 files changed, 73 insertions, 27 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index caea25a21c70..089ef3614155 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2273,20 +2273,30 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
current->memcg_kmem_skip_account = 0;
}
-/*
+static inline bool memcg_kmem_bypass(void)
+{
+ if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD))
+ return true;
+ return false;
+}
+
+/**
+ * memcg_kmem_get_cache: select the correct per-memcg cache for allocation
+ * @cachep: the original global kmem cache
+ *
* Return the kmem_cache we're supposed to use for a slab allocation.
* We try to use the current memcg's version of the cache.
*
- * If the cache does not exist yet, if we are the first user of it,
- * we either create it immediately, if possible, or create it asynchronously
- * in a workqueue.
- * In the latter case, we will let the current allocation go through with
- * the original cache.
+ * If the cache does not exist yet, if we are the first user of it, we
+ * create it asynchronously in a workqueue and let the current allocation
+ * go through with the original cache.
*
- * Can't be called in interrupt context or from kernel threads.
- * This function needs to be called with rcu_read_lock() held.
+ * This function takes a reference to the cache it returns to assure it
+ * won't get destroyed while we are working with it. Once the caller is
+ * done with it, memcg_kmem_put_cache() must be called to release the
+ * reference.
*/
-struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
+struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep)
{
struct mem_cgroup *memcg;
struct kmem_cache *memcg_cachep;
@@ -2294,10 +2304,7 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
VM_BUG_ON(!is_root_cache(cachep));
- if (cachep->flags & SLAB_ACCOUNT)
- gfp |= __GFP_ACCOUNT;
-
- if (!(gfp & __GFP_ACCOUNT))
+ if (memcg_kmem_bypass())
return cachep;
if (current->memcg_kmem_skip_account)
@@ -2330,14 +2337,27 @@ out:
return cachep;
}
-void __memcg_kmem_put_cache(struct kmem_cache *cachep)
+/**
+ * memcg_kmem_put_cache: drop reference taken by memcg_kmem_get_cache
+ * @cachep: the cache returned by memcg_kmem_get_cache
+ */
+void memcg_kmem_put_cache(struct kmem_cache *cachep)
{
if (!is_root_cache(cachep))
css_put(&cachep->memcg_params.memcg->css);
}
-int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
- struct mem_cgroup *memcg)
+/**
+ * memcg_kmem_charge: charge a kmem page
+ * @page: page to charge
+ * @gfp: reclaim mode
+ * @order: allocation order
+ * @memcg: memory cgroup to charge
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+ struct mem_cgroup *memcg)
{
unsigned int nr_pages = 1 << order;
struct page_counter *counter;
@@ -2358,19 +2378,34 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
return 0;
}
-int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+/**
+ * memcg_kmem_charge: charge a kmem page to the current memory cgroup
+ * @page: page to charge
+ * @gfp: reclaim mode
+ * @order: allocation order
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
{
struct mem_cgroup *memcg;
int ret = 0;
+ if (memcg_kmem_bypass())
+ return 0;
+
memcg = get_mem_cgroup_from_mm(current->mm);
if (!mem_cgroup_is_root(memcg))
- ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+ ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
css_put(&memcg->css);
return ret;
}
-
-void __memcg_kmem_uncharge(struct page *page, int order)
+/**
+ * memcg_kmem_uncharge: uncharge a kmem page
+ * @page: page to uncharge
+ * @order: allocation order
+ */
+void memcg_kmem_uncharge(struct page *page, int order)
{
struct mem_cgroup *memcg = page->mem_cgroup;
unsigned int nr_pages = 1 << order;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 13cf4c665321..de2491c42d4f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4009,7 +4009,8 @@ struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order)
struct page *page;
page = alloc_pages(gfp_mask, order);
- if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
+ if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) &&
+ page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
__free_pages(page, order);
page = NULL;
}
@@ -4021,7 +4022,8 @@ struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
struct page *page;
page = alloc_pages_node(nid, gfp_mask, order);
- if (page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
+ if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) &&
+ page && memcg_kmem_charge(page, gfp_mask, order) != 0) {
__free_pages(page, order);
page = NULL;
}
@@ -4034,7 +4036,8 @@ struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
*/
void __free_kmem_pages(struct page *page, unsigned int order)
{
- memcg_kmem_uncharge(page, order);
+ if (memcg_kmem_enabled())
+ memcg_kmem_uncharge(page, order);
__free_pages(page, order);
}
diff --git a/mm/slab.h b/mm/slab.h
index 5fa8b8f20eb1..f33980ab0406 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -254,8 +254,7 @@ static __always_inline int memcg_charge_slab(struct page *page,
if (is_root_cache(s))
return 0;
- ret = __memcg_kmem_charge_memcg(page, gfp, order,
- s->memcg_params.memcg);
+ ret = memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
if (ret)
return ret;
@@ -269,6 +268,9 @@ static __always_inline int memcg_charge_slab(struct page *page,
static __always_inline void memcg_uncharge_slab(struct page *page, int order,
struct kmem_cache *s)
{
+ if (!memcg_kmem_enabled())
+ return;
+
memcg_kmem_update_page_stat(page,
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
@@ -391,7 +393,11 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
if (should_failslab(s, flags))
return NULL;
- return memcg_kmem_get_cache(s, flags);
+ if (memcg_kmem_enabled() &&
+ ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
+ return memcg_kmem_get_cache(s);
+
+ return s;
}
static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
@@ -408,7 +414,9 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
s->flags, flags);
kasan_slab_alloc(s, object, flags);
}
- memcg_kmem_put_cache(s);
+
+ if (memcg_kmem_enabled())
+ memcg_kmem_put_cache(s);
}
#ifndef CONFIG_SLOB