mm: memcg: do not trap chargers with full callstack on OOM

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / linux / memcontrol.h

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6c41609..89d576c 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -41,6 +41,23 @@ struct mem_cgroup_reclaim_cookie {
        unsigned int generation;
 };
 
+enum mem_cgroup_filter_t {
+       VISIT,          /* visit current node */
+       SKIP,           /* skip the current node and continue traversal */
+       SKIP_TREE,      /* skip the whole subtree and continue traversal */
+};
+
+/*
+ * mem_cgroup_filter_t predicate might instruct mem_cgroup_iter_cond how to
+ * iterate through the hierarchy tree. Each tree element is checked by the
+ * predicate before it is returned by the iterator. If a filter returns
+ * SKIP or SKIP_TREE then the iterator code continues traversal (with the
+ * next node down the hierarchy or the next node that doesn't belong under the
+ * memcg's subtree).
+ */
+typedef enum mem_cgroup_filter_t
+(*mem_cgroup_iter_filter)(struct mem_cgroup *memcg, struct mem_cgroup *root);
+
 #ifdef CONFIG_MEMCG
 /*
  * All "charge" functions with gfp_mask should use GFP_KERNEL or
@@ -108,9 +125,18 @@ mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
 extern void mem_cgroup_end_migration(struct mem_cgroup *memcg,
        struct page *oldpage, struct page *newpage, bool migration_ok);
 
-struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
-                                  struct mem_cgroup *,
-                                  struct mem_cgroup_reclaim_cookie *);
+struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root,
+                                  struct mem_cgroup *prev,
+                                  struct mem_cgroup_reclaim_cookie *reclaim,
+                                  mem_cgroup_iter_filter cond);
+
+static inline struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
+                                  struct mem_cgroup *prev,
+                                  struct mem_cgroup_reclaim_cookie *reclaim)
+{
+       return mem_cgroup_iter_cond(root, prev, reclaim, NULL);
+}
+
 void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);
 
 /*
@@ -125,6 +151,48 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
 extern void mem_cgroup_replace_page_cache(struct page *oldpage,
                                        struct page *newpage);
 
+/**
+ * mem_cgroup_toggle_oom - toggle the memcg OOM killer for the current task
+ * @new: true to enable, false to disable
+ *
+ * Toggle whether a failed memcg charge should invoke the OOM killer
+ * or just return -ENOMEM.  Returns the previous toggle state.
+ *
+ * NOTE: Any path that enables the OOM killer before charging must
+ *       call mem_cgroup_oom_synchronize() afterward to finalize the
+ *       OOM handling and clean up.
+ */
+static inline bool mem_cgroup_toggle_oom(bool new)
+{
+       bool old;
+
+       old = current->memcg_oom.may_oom;
+       current->memcg_oom.may_oom = new;
+
+       return old;
+}
+
+static inline void mem_cgroup_enable_oom(void)
+{
+       bool old = mem_cgroup_toggle_oom(true);
+
+       WARN_ON(old == true);
+}
+
+static inline void mem_cgroup_disable_oom(void)
+{
+       bool old = mem_cgroup_toggle_oom(false);
+
+       WARN_ON(old == false);
+}
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+       return p->memcg_oom.in_memcg_oom;
+}
+
+bool mem_cgroup_oom_synchronize(void);
+
 #ifdef CONFIG_MEMCG_SWAP
 extern int do_swap_account;
 #endif
@@ -180,9 +248,9 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
        mem_cgroup_update_page_stat(page, idx, -1);
 }
 
-unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
-                                               gfp_t gfp_mask,
-                                               unsigned long *total_scanned);
+enum mem_cgroup_filter_t
+mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
+               struct mem_cgroup *root);
 
 void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
@@ -296,6 +364,15 @@ static inline void mem_cgroup_end_migration(struct mem_cgroup *memcg,
                struct page *oldpage, struct page *newpage, bool migration_ok)
 {
 }
+static inline struct mem_cgroup *
+mem_cgroup_iter_cond(struct mem_cgroup *root,
+               struct mem_cgroup *prev,
+               struct mem_cgroup_reclaim_cookie *reclaim,
+               mem_cgroup_iter_filter cond)
+{
+       /* first call must return non-NULL, second return NULL */
+       return (struct mem_cgroup *)(unsigned long)!prev;
+}
 
 static inline struct mem_cgroup *
 mem_cgroup_iter(struct mem_cgroup *root,
@@ -348,6 +425,29 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page,
 {
 }
 
+static inline bool mem_cgroup_toggle_oom(bool new)
+{
+       return false;
+}
+
+static inline void mem_cgroup_enable_oom(void)
+{
+}
+
+static inline void mem_cgroup_disable_oom(void)
+{
+}
+
+static inline bool task_in_memcg_oom(struct task_struct *p)
+{
+       return false;
+}
+
+static inline bool mem_cgroup_oom_synchronize(void)
+{
+       return false;
+}
+
 static inline void mem_cgroup_inc_page_stat(struct page *page,
                                            enum mem_cgroup_page_stat_item idx)
 {
@@ -359,11 +459,11 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
 }
 
 static inline
-unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
-                                           gfp_t gfp_mask,
-                                           unsigned long *total_scanned)
+enum mem_cgroup_filter_t
+mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
+               struct mem_cgroup *root)
 {
-       return 0;
+       return VISIT;
 }
 
 static inline void mem_cgroup_split_huge_fixup(struct page *head)