1 files changed, 20 insertions, 61 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 26ea8636758f8..3a2484884cfd1 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -843,7 +843,7 @@ static bool task_will_free_mem(struct task_struct *task)
 	return ret;
 }
 
-static void __oom_kill_process(struct task_struct *victim)
+static void __oom_kill_process(struct task_struct *victim, const char *message)
 {
 	struct task_struct *p;
 	struct mm_struct *mm;
@@ -874,8 +874,9 @@ static void __oom_kill_process(struct task_struct *victim)
 	 */
 	do_send_sig_info(SIGKILL, SEND_SIG_PRIV, victim, PIDTYPE_TGID);
 	mark_oom_victim(victim);
-	pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
-		task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
+	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
+		message, task_pid_nr(victim), victim->comm,
+		K(victim->mm->total_vm),
 		K(get_mm_counter(victim->mm, MM_ANONPAGES)),
 		K(get_mm_counter(victim->mm, MM_FILEPAGES)),
 		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)));
@@ -926,24 +927,20 @@ static void __oom_kill_process(struct task_struct *victim)
  * Kill provided task unless it's secured by setting
  * oom_score_adj to OOM_SCORE_ADJ_MIN.
  */
-static int oom_kill_memcg_member(struct task_struct *task, void *unused)
+static int oom_kill_memcg_member(struct task_struct *task, void *message)
 {
-	if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
+	if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN &&
+	    !is_global_init(task)) {
 		get_task_struct(task);
-		__oom_kill_process(task);
+		__oom_kill_process(task, message);
 	}
 	return 0;
 }
 
 static void oom_kill_process(struct oom_control *oc, const char *message)
 {
-	struct task_struct *p = oc->chosen;
-	unsigned int points = oc->chosen_points;
-	struct task_struct *victim = p;
-	struct task_struct *child;
-	struct task_struct *t;
+	struct task_struct *victim = oc->chosen;
 	struct mem_cgroup *oom_group;
-	unsigned int victim_points = 0;
 	static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
 					      DEFAULT_RATELIMIT_BURST);
 
@@ -952,57 +949,18 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
 	 * its children or threads, just give it access to memory reserves
 	 * so it can die quickly
 	 */
-	task_lock(p);
-	if (task_will_free_mem(p)) {
-		mark_oom_victim(p);
-		wake_oom_reaper(p);
-		task_unlock(p);
-		put_task_struct(p);
+	task_lock(victim);
+	if (task_will_free_mem(victim)) {
+		mark_oom_victim(victim);
+		wake_oom_reaper(victim);
+		task_unlock(victim);
+		put_task_struct(victim);
 		return;
 	}
-	task_unlock(p);
+	task_unlock(victim);
 
 	if (__ratelimit(&oom_rs))
-		dump_header(oc, p);
-
-	pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
-		message, task_pid_nr(p), p->comm, points);
-
-	/*
-	 * If any of p's children has a different mm and is eligible for kill,
-	 * the one with the highest oom_badness() score is sacrificed for its
-	 * parent.  This attempts to lose the minimal amount of work done while
-	 * still freeing memory.
-	 */
-	read_lock(&tasklist_lock);
-
-	/*
-	 * The task 'p' might have already exited before reaching here. The
-	 * put_task_struct() will free task_struct 'p' while the loop still try
-	 * to access the field of 'p', so, get an extra reference.
-	 */
-	get_task_struct(p);
-	for_each_thread(p, t) {
-		list_for_each_entry(child, &t->children, sibling) {
-			unsigned int child_points;
-
-			if (process_shares_mm(child, p->mm))
-				continue;
-			/*
-			 * oom_badness() returns 0 if the thread is unkillable
-			 */
-			child_points = oom_badness(child,
-				oc->memcg, oc->nodemask, oc->totalpages);
-			if (child_points > victim_points) {
-				put_task_struct(victim);
-				victim = child;
-				victim_points = child_points;
-				get_task_struct(victim);
-			}
-		}
-	}
-	put_task_struct(p);
-	read_unlock(&tasklist_lock);
+		dump_header(oc, victim);
 
 	/*
 	 * Do we need to kill the entire memory cgroup?
@@ -1011,14 +969,15 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
 	 */
 	oom_group = mem_cgroup_get_oom_group(victim, oc->memcg);
 
-	__oom_kill_process(victim);
+	__oom_kill_process(victim, message);
 
 	/*
 	 * If necessary, kill all tasks in the selected memory cgroup.
 	 */
 	if (oom_group) {
 		mem_cgroup_print_oom_group(oom_group);
-		mem_cgroup_scan_tasks(oom_group, oom_kill_memcg_member, NULL);
+		mem_cgroup_scan_tasks(oom_group, oom_kill_memcg_member,
+				      (void*)message);
 		mem_cgroup_put(oom_group);
 	}
 }