1 files changed, 20 insertions, 61 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 26ea8636758f..3a2484884cfd 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);
         }
 }