1 files changed, 38 insertions, 46 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 92bcf1db16b2..175a67a78a99 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -58,6 +58,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 	unsigned long points, cpu_time, run_time;
 	struct mm_struct *mm;
 	struct task_struct *child;
+	int oom_adj;
 
 	task_lock(p);
 	mm = p->mm;
@@ -65,6 +66,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 		task_unlock(p);
 		return 0;
 	}
+	oom_adj = mm->oom_adj;
+	if (oom_adj == OOM_DISABLE) {
+		task_unlock(p);
+		return 0;
+	}
 
 	/*
 	 * The memory size of the process is the basis for the badness.
@@ -148,15 +154,15 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 		points /= 8;
 
 	/*
-	 * Adjust the score by oomkilladj.
+	 * Adjust the score by oom_adj.
 	 */
-	if (p->oomkilladj) {
-		if (p->oomkilladj > 0) {
+	if (oom_adj) {
+		if (oom_adj > 0) {
 			if (!points)
 				points = 1;
-			points <<= p->oomkilladj;
+			points <<= oom_adj;
 		} else
-			points >>= -(p->oomkilladj);
+			points >>= -(oom_adj);
 	}
 
 #ifdef DEBUG
@@ -251,11 +257,8 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
 			*ppoints = ULONG_MAX;
 		}
 
-		if (p->oomkilladj == OOM_DISABLE)
-			continue;
-
 		points = badness(p, uptime.tv_sec);
-		if (points > *ppoints || !chosen) {
+		if (points > *ppoints) {
 			chosen = p;
 			*ppoints = points;
 		}
@@ -284,22 +287,27 @@ static void dump_tasks(const struct mem_cgroup *mem)
 	printk(KERN_INFO "[ pid ]   uid  tgid total_vm      rss cpu oom_adj "
 	       "name\n");
 	do_each_thread(g, p) {
-		/*
-		 * total_vm and rss sizes do not exist for tasks with a
-		 * detached mm so there's no need to report them.
-		 */
-		if (!p->mm)
-			continue;
+		struct mm_struct *mm;
+
 		if (mem && !task_in_mem_cgroup(p, mem))
 			continue;
 		if (!thread_group_leader(p))
 			continue;
 
 		task_lock(p);
+		mm = p->mm;
+		if (!mm) {
+			/*
+			 * total_vm and rss sizes do not exist for tasks with no
+			 * mm so there's no need to report them; they can't be
+			 * oom killed anyway.
+			 */
+			task_unlock(p);
+			continue;
+		}
 		printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d     %3d %s\n",
-		       p->pid, __task_cred(p)->uid, p->tgid,
-		       p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p),
-		       p->oomkilladj, p->comm);
+		       p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm,
+		       get_mm_rss(mm), (int)task_cpu(p), mm->oom_adj, p->comm);
 		task_unlock(p);
 	} while_each_thread(g, p);
 }
@@ -317,11 +325,8 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
 		return;
 	}
 
-	if (!p->mm) {
-		WARN_ON(1);
-		printk(KERN_WARNING "tried to kill an mm-less task!\n");
+	if (!p->mm)
 		return;
-	}
 
 	if (verbose)
 		printk(KERN_ERR "Killed process %d (%s)\n",
@@ -343,28 +348,13 @@ static int oom_kill_task(struct task_struct *p)
 	struct mm_struct *mm;
 	struct task_struct *g, *q;
 
+	task_lock(p);
 	mm = p->mm;
-
-	/* WARNING: mm may not be dereferenced since we did not obtain its
-	 * value from get_task_mm(p).  This is OK since all we need to do is
-	 * compare mm to q->mm below.
-	 *
-	 * Furthermore, even if mm contains a non-NULL value, p->mm may
-	 * change to NULL at any time since we do not hold task_lock(p).
-	 * However, this is of no concern to us.
-	 */
-
-	if (mm == NULL)
+	if (!mm || mm->oom_adj == OOM_DISABLE) {
+		task_unlock(p);
 		return 1;
-
-	/*
-	 * Don't kill the process if any threads are set to OOM_DISABLE
-	 */
-	do_each_thread(g, q) {
-		if (q->mm == mm && q->oomkilladj == OOM_DISABLE)
-			return 1;
-	} while_each_thread(g, q);
-
+	}
+	task_unlock(p);
 	__oom_kill_task(p, 1);
 
 	/*
@@ -387,10 +377,11 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 	struct task_struct *c;
 
 	if (printk_ratelimit()) {
-		printk(KERN_WARNING "%s invoked oom-killer: "
-			"gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
-			current->comm, gfp_mask, order, current->oomkilladj);
 		task_lock(current);
+		printk(KERN_WARNING "%s invoked oom-killer: "
+			"gfp_mask=0x%x, order=%d, oom_adj=%d\n",
+			current->comm, gfp_mask, order,
+			current->mm ? current->mm->oom_adj : OOM_DISABLE);
 		cpuset_print_task_mems_allowed(current);
 		task_unlock(current);
 		dump_stack();
@@ -403,8 +394,9 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 	/*
 	 * If the task is already exiting, don't alarm the sysadmin or kill
 	 * its children or threads, just set TIF_MEMDIE so it can die quickly
+	 * if its mm is still attached.
 	 */
-	if (p->flags & PF_EXITING) {
+	if (p->mm && (p->flags & PF_EXITING)) {
 		__oom_kill_task(p, 0);
 		return 0;
 	}