memcg: localize memcg_kmem_enabled() check

Move the memcg_kmem_enabled() checks into memcg kmem charge/uncharge
functions, so, the users don't have to explicitly check that condition.

This is purely code cleanup patch without any functional change.  Only
the order of checks in memcg_charge_slab() can potentially be changed
but the functionally it will be same.  This should not matter as
memcg_charge_slab() is not in the hot path.

Link: http://lkml.kernel.org/r/20190103161203.162375-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/pipe.c b/fs/pipe.c
index bdc5d3c..51d5fd8 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -140,8 +140,7 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
        struct page *page = buf->page;
 
        if (page_count(page) == 1) {
-               if (memcg_kmem_enabled())
-                       memcg_kmem_uncharge(page, 0);
+               memcg_kmem_uncharge(page, 0);
                __SetPageLocked(page);
                return 0;
        }

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 83ae11c..b0eb29e 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1273,12 +1273,12 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 
 struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
 void memcg_kmem_put_cache(struct kmem_cache *cachep);
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
-                           struct mem_cgroup *memcg);
 
 #ifdef CONFIG_MEMCG_KMEM
-int memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
-void memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
+void __memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+                             struct mem_cgroup *memcg);
 
 extern struct static_key_false memcg_kmem_enabled_key;
 extern struct workqueue_struct *memcg_kmem_cache_wq;
@@ -1300,6 +1300,26 @@ static inline bool memcg_kmem_enabled(void)
        return static_branch_unlikely(&memcg_kmem_enabled_key);
 }
 
+static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+{
+       if (memcg_kmem_enabled())
+               return __memcg_kmem_charge(page, gfp, order);
+       return 0;
+}
+
+static inline void memcg_kmem_uncharge(struct page *page, int order)
+{
+       if (memcg_kmem_enabled())
+               __memcg_kmem_uncharge(page, order);
+}
+
+static inline int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp,
+                                         int order, struct mem_cgroup *memcg)
+{
+       if (memcg_kmem_enabled())
+               return __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+       return 0;
+}
 /*
  * helper for accessing a memcg's index. It will be used as an index in the
  * child cache array in kmem_cache, and also to derive its name. This function
@@ -1325,6 +1345,15 @@ static inline void memcg_kmem_uncharge(struct page *page, int order)
 {
 }
 
+static inline int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+{
+       return 0;
+}
+
+static inline void __memcg_kmem_uncharge(struct page *page, int order)
+{
+}
+
 #define for_each_memcg_cache_index(_idx)       \
        for (; NULL; )
 

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index af7f18b..72414bb 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2573,7 +2573,7 @@ void memcg_kmem_put_cache(struct kmem_cache *cachep)
 }
 
 /**
- * memcg_kmem_charge_memcg: charge a kmem page
+ * __memcg_kmem_charge_memcg: charge a kmem page
  * @page: page to charge
  * @gfp: reclaim mode
  * @order: allocation order
@@ -2581,7 +2581,7 @@ void memcg_kmem_put_cache(struct kmem_cache *cachep)
  *
  * Returns 0 on success, an error code on failure.
  */
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
                            struct mem_cgroup *memcg)
 {
        unsigned int nr_pages = 1 << order;
@@ -2604,24 +2604,24 @@ int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 }
 
 /**
- * memcg_kmem_charge: charge a kmem page to the current memory cgroup
+ * __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)
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 {
        struct mem_cgroup *memcg;
        int ret = 0;
 
-       if (mem_cgroup_disabled() || memcg_kmem_bypass())
+       if (memcg_kmem_bypass())
                return 0;
 
        memcg = get_mem_cgroup_from_current();
        if (!mem_cgroup_is_root(memcg)) {
-               ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
+               ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
                if (!ret)
                        __SetPageKmemcg(page);
        }
@@ -2629,11 +2629,11 @@ int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
        return ret;
 }
 /**
- * memcg_kmem_uncharge: uncharge a kmem page
+ * __memcg_kmem_uncharge: uncharge a kmem page
  * @page: page to uncharge
  * @order: allocation order
  */
-void memcg_kmem_uncharge(struct page *page, int 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 1f9f140..034b8b6 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1056,7 +1056,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
        if (PageMappingFlags(page))
                page->mapping = NULL;
        if (memcg_kmem_enabled() && PageKmemcg(page))
-               memcg_kmem_uncharge(page, order);
+               __memcg_kmem_uncharge(page, order);
        if (check_free)
                bad += free_pages_check(page);
        if (bad)
@@ -4568,7 +4568,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
 
 out:
        if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
-           unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
+           unlikely(__memcg_kmem_charge(page, gfp_mask, order) != 0)) {
                __free_pages(page, order);
                page = NULL;
        }

diff --git a/mm/slab.h b/mm/slab.h
index 3841053..e5e6658 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -276,8 +276,6 @@ static __always_inline int memcg_charge_slab(struct page *page,
                                             gfp_t gfp, int order,
                                             struct kmem_cache *s)
 {
-       if (!memcg_kmem_enabled())
-               return 0;
        if (is_root_cache(s))
                return 0;
        return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
@@ -286,8 +284,6 @@ 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_uncharge(page, order);
 }