6 files changed, 6 insertions, 49 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 25dcbe5fc356..36254645b7cc 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -841,10 +841,6 @@ static int exec_mmap(struct mm_struct *mm)
         tsk->mm = mm;
         tsk->active_mm = mm;
         activate_mm(active_mm, mm);
-        if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
-                atomic_dec(&old_mm->oom_disable_count);
-                atomic_inc(&tsk->mm->oom_disable_count);
-        }
         task_unlock(tsk);
         arch_pick_mmap_layout(mm);
         if (old_mm) {
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 5eb02069e1b8..8f0087e20e16 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1107,13 +1107,6 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
                 goto err_sighand;
         }
 
-        if (oom_adjust != task->signal->oom_adj) {
-                if (oom_adjust == OOM_DISABLE)
-                        atomic_inc(&task->mm->oom_disable_count);
-                if (task->signal->oom_adj == OOM_DISABLE)
-                        atomic_dec(&task->mm->oom_disable_count);
-        }
-
         /*
          * Warn that /proc/pid/oom_adj is deprecated, see
          * Documentation/feature-removal-schedule.txt.
@@ -1215,12 +1208,6 @@ static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
                 goto err_sighand;
         }
 
-        if (oom_score_adj != task->signal->oom_score_adj) {
-                if (oom_score_adj == OOM_SCORE_ADJ_MIN)
-                        atomic_inc(&task->mm->oom_disable_count);
-                if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
-                        atomic_dec(&task->mm->oom_disable_count);
-        }
         task->signal->oom_score_adj = oom_score_adj;
         if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
                 task->signal->oom_score_adj_min = oom_score_adj;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index c93d00a6e95d..6456624aa964 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -336,9 +336,6 @@ struct mm_struct {
         unsigned int token_priority;
         unsigned int last_interval;
 
-        /* How many tasks sharing this mm are OOM_DISABLE */
-        atomic_t oom_disable_count;
-
         unsigned long flags; /* Must use atomic bitops to access the bits */
 
         struct core_state *core_state; /* coredumping support */
diff --git a/kernel/exit.c b/kernel/exit.c
index 2913b3509d42..d0b7d988f873 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -681,8 +681,6 @@ static void exit_mm(struct task_struct * tsk)
         enter_lazy_tlb(mm, current);
         /* We don't want this task to be frozen prematurely */
         clear_freeze_flag(tsk);
-        if (tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
-                atomic_dec(&mm->oom_disable_count);
         task_unlock(tsk);
         mm_update_next_owner(mm);
         mmput(mm);
diff --git a/kernel/fork.c b/kernel/fork.c
index 8e6b6f4fb272..70d76191afb9 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -501,7 +501,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
         mm->cached_hole_size = ~0UL;
         mm_init_aio(mm);
         mm_init_owner(mm, p);
-        atomic_set(&mm->oom_disable_count, 0);
 
         if (likely(!mm_alloc_pgd(mm))) {
                 mm->def_flags = 0;
@@ -816,8 +815,6 @@ good_mm:
         /* Initializing for Swap token stuff */
         mm->token_priority = 0;
         mm->last_interval = 0;
-        if (tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
-                atomic_inc(&mm->oom_disable_count);
 
         tsk->mm = mm;
         tsk->active_mm = mm;
@@ -1391,13 +1388,8 @@ bad_fork_cleanup_io:
 bad_fork_cleanup_namespaces:
         exit_task_namespaces(p);
 bad_fork_cleanup_mm:
-        if (p->mm) {
-                task_lock(p);
-                if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
-                        atomic_dec(&p->mm->oom_disable_count);
-                task_unlock(p);
+        if (p->mm)
                 mmput(p->mm);
-        }
 bad_fork_cleanup_signal:
         if (!(clone_flags & CLONE_THREAD))
                 free_signal_struct(p->signal);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index b0d8943bc9fd..2b97e8f04607 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -54,13 +54,7 @@ int test_set_oom_score_adj(int new_val)
 
         spin_lock_irq(&sighand->siglock);
         old_val = current->signal->oom_score_adj;
-        if (new_val != old_val) {
-                if (new_val == OOM_SCORE_ADJ_MIN)
-                        atomic_inc(&current->mm->oom_disable_count);
-                else if (old_val == OOM_SCORE_ADJ_MIN)
-                        atomic_dec(&current->mm->oom_disable_count);
-                current->signal->oom_score_adj = new_val;
-        }
+        current->signal->oom_score_adj = new_val;
         spin_unlock_irq(&sighand->siglock);
 
         return old_val;
@@ -173,16 +167,6 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
                 return 0;
 
         /*
-         * Shortcut check for a thread sharing p->mm that is OOM_SCORE_ADJ_MIN
-         * so the entire heuristic doesn't need to be executed for something
-         * that cannot be killed.
-         */
-        if (atomic_read(&p->mm->oom_disable_count)) {
-                task_unlock(p);
-                return 0;
-        }
-
-        /*
          * The memory controller may have a limit of 0 bytes, so avoid a divide
          * by zero, if necessary.
          */
@@ -451,6 +435,9 @@ static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
         for_each_process(q)
                 if (q->mm == mm && !same_thread_group(q, p) &&
                     !(q->flags & PF_KTHREAD)) {
+                        if (q->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
+                                continue;
+
                         task_lock(q);   /* Protect ->comm from prctl() */
                         pr_err("Kill process %d (%s) sharing same memory\n",
                                 task_pid_nr(q), q->comm);
@@ -727,7 +714,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
         read_lock(&tasklist_lock);
         if (sysctl_oom_kill_allocating_task &&
             !oom_unkillable_task(current, NULL, nodemask) &&
-            current->mm && !atomic_read(&current->mm->oom_disable_count)) {
+            current->mm) {
                 /*
                  * oom_kill_process() needs tasklist_lock held.  If it returns
                  * non-zero, current could not be killed so we must fallback to