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authorJohannes Weiner <hannes@cmpxchg.org>2013-09-12 15:13:42 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-21 09:22:56 -0800
commit11f34787b50ce71f66b85ad8790beaa5eee3f897 (patch)
treeadcde8d7963d1426991067916366ae3f5ec11c8a /include
parented368ae78e6eafc10368e97246610d676bec3060 (diff)
mm: memcg: enable memcg OOM killer only for user faults
commit 519e52473ebe9db5cdef44670d5a97f1fd53d721 upstream. System calls and kernel faults (uaccess, gup) can handle an out of memory situation gracefully and just return -ENOMEM. Enable the memcg OOM killer only for user faults, where it's really the only option available. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/memcontrol.h44
-rw-r--r--include/linux/sched.h3
2 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d6183f06d8c1..2c911c95b1ac 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -124,6 +124,37 @@ 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.
+ */
+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);
+}
+
#ifdef CONFIG_MEMCG_SWAP
extern int do_swap_account;
#endif
@@ -347,6 +378,19 @@ 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 void mem_cgroup_inc_page_stat(struct page *page,
enum mem_cgroup_page_stat_item idx)
{
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f87e9a8d364f..42a58ce480bc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1411,6 +1411,9 @@ struct task_struct {
unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
} memcg_batch;
unsigned int memcg_kmem_skip_account;
+ struct memcg_oom_info {
+ unsigned int may_oom:1;
+ } memcg_oom;
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
atomic_t ptrace_bp_refcnt;