Reset to 3.12.37

1 files changed, 54 insertions, 26 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e73f01c..712a0f8 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -47,19 +47,21 @@ static DEFINE_SPINLOCK(zone_scan_lock);
 #ifdef CONFIG_NUMA
 /**
  * has_intersects_mems_allowed() - check task eligiblity for kill
- * @tsk: task struct of which task to consider
+ * @start: task struct of which task to consider
  * @mask: nodemask passed to page allocator for mempolicy ooms
  *
  * Task eligibility is determined by whether or not a candidate task, @tsk,
  * shares the same mempolicy nodes as current if it is bound by such a policy
  * and whether or not it has the same set of allowed cpuset nodes.
  */
-static bool has_intersects_mems_allowed(struct task_struct *tsk,
+static bool has_intersects_mems_allowed(struct task_struct *start,
 					const nodemask_t *mask)
 {
-	struct task_struct *start = tsk;
+	struct task_struct *tsk;
+	bool ret = false;
 
-	do {
+	rcu_read_lock();
+	for_each_thread(start, tsk) {
 		if (mask) {
 			/*
 			 * If this is a mempolicy constrained oom, tsk's
@@ -67,19 +69,20 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
 			 * mempolicy intersects current, otherwise it may be
 			 * needlessly killed.
 			 */
-			if (mempolicy_nodemask_intersects(tsk, mask))
-				return true;
+			ret = mempolicy_nodemask_intersects(tsk, mask);
 		} else {
 			/*
 			 * This is not a mempolicy constrained oom, so only
 			 * check the mems of tsk's cpuset.
 			 */
-			if (cpuset_mems_allowed_intersects(current, tsk))
-				return true;
+			ret = cpuset_mems_allowed_intersects(current, tsk);
 		}
-	} while_each_thread(start, tsk);
+		if (ret)
+			break;
+	}
+	rcu_read_unlock();
 
-	return false;
+	return ret;
 }
 #else
 static bool has_intersects_mems_allowed(struct task_struct *tsk,
@@ -97,16 +100,21 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
  */
 struct task_struct *find_lock_task_mm(struct task_struct *p)
 {
-	struct task_struct *t = p;
+	struct task_struct *t;
 
-	do {
+	rcu_read_lock();
+
+	for_each_thread(p, t) {
 		task_lock(t);
 		if (likely(t->mm))
-			return t;
+			goto found;
 		task_unlock(t);
-	} while_each_thread(p, t);
+	}
+	t = NULL;
+found:
+	rcu_read_unlock();
 
-	return NULL;
+	return t;
 }
 
 /* return true if the task is not adequate as candidate victim task. */
@@ -301,7 +309,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 	unsigned long chosen_points = 0;
 
 	rcu_read_lock();
-	do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		unsigned int points;
 
 		switch (oom_scan_process_thread(p, totalpages, nodemask,
@@ -319,11 +327,15 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 			break;
 		};
 		points = oom_badness(p, NULL, nodemask, totalpages);
-		if (points > chosen_points) {
-			chosen = p;
-			chosen_points = points;
-		}
-	} while_each_thread(g, p);
+		if (!points || points < chosen_points)
+			continue;
+		/* Prefer thread group leaders for display purposes */
+		if (points == chosen_points && thread_group_leader(chosen))
+			continue;
+
+		chosen = p;
+		chosen_points = points;
+	}
 	if (chosen)
 		get_task_struct(chosen);
 	rcu_read_unlock();
@@ -394,6 +406,23 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
 		dump_tasks(memcg, nodemask);
 }
 
+/*
+ * Number of OOM killer invocations (including memcg OOM killer).
+ * Primarily used by PM freezer to check for potential races with
+ * OOM killed frozen task.
+ */
+static atomic_t oom_kills = ATOMIC_INIT(0);
+
+int oom_kills_count(void)
+{
+	return atomic_read(&oom_kills);
+}
+
+void note_oom_kill(void)
+{
+	atomic_inc(&oom_kills);
+}
+
 #define K(x) ((x) << (PAGE_SHIFT-10))
 /*
  * Must be called while holding a reference to p, which will be released upon
@@ -406,7 +435,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 {
 	struct task_struct *victim = p;
 	struct task_struct *child;
-	struct task_struct *t = p;
+	struct task_struct *t;
 	struct mm_struct *mm;
 	unsigned int victim_points = 0;
 	static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
@@ -437,7 +466,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 	 * still freeing memory.
 	 */
 	read_lock(&tasklist_lock);
-	do {
+	for_each_thread(p, t) {
 		list_for_each_entry(child, &t->children, sibling) {
 			unsigned int child_points;
 
@@ -455,13 +484,11 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 				get_task_struct(victim);
 			}
 		}
-	} while_each_thread(p, t);
+	}
 	read_unlock(&tasklist_lock);
 
-	rcu_read_lock();
 	p = find_lock_task_mm(victim);
 	if (!p) {
-		rcu_read_unlock();
 		put_task_struct(victim);
 		return;
 	} else if (victim != p) {
@@ -487,6 +514,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 	 * That thread will now get access to memory reserves since it has a
 	 * pending fatal signal.
 	 */
+	rcu_read_lock();
 	for_each_process(p)
 		if (p->mm == mm && !same_thread_group(p, victim) &&
 		    !(p->flags & PF_KTHREAD)) {