[Devel] [PATCH v12 04/18] memcg: move several kmemcg functions upper

[Vladimir Davydov]

I need to move memcg_{stop,resume}_kmem_account() and
memcg_caches_array_size() upper since I am going to use them in
per-memcg lrus implementation introduced by the following patches.
These functions are very simple and do not depend on other kmemcg
bits so it is better to keep them on top anyway.

Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Michal Hocko <mhocko at suse.cz>
Cc: Balbir Singh <bsingharora at gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
---
 mm/memcontrol.c |   92 +++++++++++++++++++++++++++----------------------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3a4e2f8..3a92ab3 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2983,6 +2983,52 @@ static int memcg_cache_idx(struct mem_cgroup *memcg)
 	return ret;
 }
 
+static size_t memcg_caches_array_size(int num_groups)
+{
+	ssize_t size;
+	if (num_groups <= 0)
+		return 0;
+
+	size = 2 * num_groups;
+	if (size < MEMCG_CACHES_MIN_SIZE)
+		size = MEMCG_CACHES_MIN_SIZE;
+	else if (size > MEMCG_CACHES_MAX_SIZE)
+		size = MEMCG_CACHES_MAX_SIZE;
+
+	return size;
+}
+
+/*
+ * During the creation a new cache, we need to disable our accounting mechanism
+ * altogether. This is true even if we are not creating, but rather just
+ * enqueing new caches to be created.
+ *
+ * This is because that process will trigger allocations; some visible, like
+ * explicit kmallocs to auxiliary data structures, name strings and internal
+ * cache structures; some well concealed, like INIT_WORK() that can allocate
+ * objects during debug.
+ *
+ * If any allocation happens during memcg_kmem_get_cache, we will recurse back
+ * to it. This may not be a bounded recursion: since the first cache creation
+ * failed to complete (waiting on the allocation), we'll just try to create the
+ * cache again, failing at the same point.
+ *
+ * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
+ * memcg_kmem_skip_account. So we enclose anything that might allocate memory
+ * inside the following two functions.
+ */
+static inline void memcg_stop_kmem_account(void)
+{
+	VM_BUG_ON(!current->mm);
+	current->memcg_kmem_skip_account++;
+}
+
+static inline void memcg_resume_kmem_account(void)
+{
+	VM_BUG_ON(!current->mm);
+	current->memcg_kmem_skip_account--;
+}
+
 /*
  * This is a bit cumbersome, but it is rarely used and avoids a backpointer
  * in the memcg_cache_params struct.
@@ -3125,21 +3171,6 @@ int memcg_update_cache_sizes(struct mem_cgroup *memcg)
 	return 0;
 }
 
-static size_t memcg_caches_array_size(int num_groups)
-{
-	ssize_t size;
-	if (num_groups <= 0)
-		return 0;
-
-	size = 2 * num_groups;
-	if (size < MEMCG_CACHES_MIN_SIZE)
-		size = MEMCG_CACHES_MIN_SIZE;
-	else if (size > MEMCG_CACHES_MAX_SIZE)
-		size = MEMCG_CACHES_MAX_SIZE;
-
-	return size;
-}
-
 /*
  * We should update the current array size iff all caches updates succeed. This
  * can only be done from the slab side. The slab mutex needs to be held when
@@ -3264,37 +3295,6 @@ out:
 	kfree(s->memcg_params);
 }
 
-/*
- * During the creation a new cache, we need to disable our accounting mechanism
- * altogether. This is true even if we are not creating, but rather just
- * enqueing new caches to be created.
- *
- * This is because that process will trigger allocations; some visible, like
- * explicit kmallocs to auxiliary data structures, name strings and internal
- * cache structures; some well concealed, like INIT_WORK() that can allocate
- * objects during debug.
- *
- * If any allocation happens during memcg_kmem_get_cache, we will recurse back
- * to it. This may not be a bounded recursion: since the first cache creation
- * failed to complete (waiting on the allocation), we'll just try to create the
- * cache again, failing at the same point.
- *
- * memcg_kmem_get_cache is prepared to abort after seeing a positive count of
- * memcg_kmem_skip_account. So we enclose anything that might allocate memory
- * inside the following two functions.
- */
-static inline void memcg_stop_kmem_account(void)
-{
-	VM_BUG_ON(!current->mm);
-	current->memcg_kmem_skip_account++;
-}
-
-static inline void memcg_resume_kmem_account(void)
-{
-	VM_BUG_ON(!current->mm);
-	current->memcg_kmem_skip_account--;
-}
-
 static void kmem_cache_destroy_work_func(struct work_struct *w)
 {
 	struct kmem_cache *cachep;
-- 
1.7.10.4