X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=mm%2Foom_kill.c;h=e916168b6e0a8e6b70b4cb513f28591442ed8746;hb=02ebbbd481635fd3ce7018e5bb19c18c0f1e4561;hp=626303b52f3ce0764d3bb1029f6bce8b5bcaa896;hpb=882aba01052476cbe3cd7339a3e6784b2437f18d;p=mv-sheeva.git

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 626303b52f3..e916168b6e0 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -32,12 +32,32 @@
 #include <linux/mempolicy.h>
 #include <linux/security.h>
 #include <linux/ptrace.h>
+#include <linux/freezer.h>
 
 int sysctl_panic_on_oom;
 int sysctl_oom_kill_allocating_task;
 int sysctl_oom_dump_tasks = 1;
 static DEFINE_SPINLOCK(zone_scan_lock);
 
+/*
+ * compare_swap_oom_score_adj() - compare and swap current's oom_score_adj
+ * @old_val: old oom_score_adj for compare
+ * @new_val: new oom_score_adj for swap
+ *
+ * Sets the oom_score_adj value for current to @new_val iff its present value is
+ * @old_val.  Usually used to reinstate a previous value to prevent racing with
+ * userspacing tuning the value in the interim.
+ */
+void compare_swap_oom_score_adj(int old_val, int new_val)
+{
+	struct sighand_struct *sighand = current->sighand;
+
+	spin_lock_irq(&sighand->siglock);
+	if (current->signal->oom_score_adj == old_val)
+		current->signal->oom_score_adj = new_val;
+	spin_unlock_irq(&sighand->siglock);
+}
+
 /**
  * test_set_oom_score_adj() - set current's oom_score_adj and return old value
  * @new_val: new oom_score_adj value
@@ -53,13 +73,7 @@ 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;
@@ -171,16 +185,6 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
 	if (!p)
 		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.
@@ -317,8 +321,11 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
 		 * blocked waiting for another task which itself is waiting
 		 * for memory. Is there a better alternative?
 		 */
-		if (test_tsk_thread_flag(p, TIF_MEMDIE))
+		if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
+			if (unlikely(frozen(p)))
+				thaw_process(p);
 			return ERR_PTR(-1UL);
+		}
 		if (!p->mm)
 			continue;
 
@@ -435,7 +442,7 @@ static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
 	task_unlock(p);
 
 	/*
-	 * Kill all processes sharing p->mm in other thread groups, if any.
+	 * Kill all user processes sharing p->mm in other thread groups, if any.
 	 * They don't get access to memory reserves or a higher scheduler
 	 * priority, though, to avoid depletion of all memory or task
 	 * starvation.  This prevents mm->mmap_sem livelock when an oom killed
@@ -445,7 +452,11 @@ static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
 	 * signal.
 	 */
 	for_each_process(q)
-		if (q->mm == mm && !same_thread_group(q, p)) {
+		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);
@@ -722,7 +733,7 @@ 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