1 files changed, 65 insertions, 29 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 558f9afe6e4e..c592965dab2f 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -509,6 +509,69 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
         spin_unlock(&zone_scan_mutex);
 }
 
+/*
+ * Must be called with tasklist_lock held for read.
+ */
+static void __out_of_memory(gfp_t gfp_mask, int order)
+{
+        if (sysctl_oom_kill_allocating_task) {
+                oom_kill_process(current, gfp_mask, order, 0, NULL,
+                                "Out of memory (oom_kill_allocating_task)");
+
+        } else {
+                unsigned long points;
+                struct task_struct *p;
+
+retry:
+                /*
+                 * Rambo mode: Shoot down a process and hope it solves whatever
+                 * issues we may have.
+                 */
+                p = select_bad_process(&points, NULL);
+
+                if (PTR_ERR(p) == -1UL)
+                        return;
+
+                /* Found nothing?!?! Either we hang forever, or we panic. */
+                if (!p) {
+                        read_unlock(&tasklist_lock);
+                        panic("Out of memory and no killable processes...\n");
+                }
+
+                if (oom_kill_process(p, gfp_mask, order, points, NULL,
+                                     "Out of memory"))
+                        goto retry;
+        }
+}
+
+/*
+ * pagefault handler calls into here because it is out of memory but
+ * doesn't know exactly how or why.
+ */
+void pagefault_out_of_memory(void)
+{
+        unsigned long freed = 0;
+
+        blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
+        if (freed > 0)
+                /* Got some memory back in the last second. */
+                return;
+
+        if (sysctl_panic_on_oom)
+                panic("out of memory from page fault. panic_on_oom is selected.\n");
+
+        read_lock(&tasklist_lock);
+        __out_of_memory(0, 0); /* unknown gfp_mask and order */
+        read_unlock(&tasklist_lock);
+
+        /*
+         * Give "p" a good chance of killing itself before we
+         * retry to allocate memory.
+         */
+        if (!test_thread_flag(TIF_MEMDIE))
+                schedule_timeout_uninterruptible(1);
+}
+
 /**
  * out_of_memory - kill the "best" process when we run out of memory
  * @zonelist: zonelist pointer
@@ -522,8 +585,6 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
  */
 void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 {
-        struct task_struct *p;
-        unsigned long points = 0;
         unsigned long freed = 0;
         enum oom_constraint constraint;
 
@@ -544,7 +605,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 
         switch (constraint) {
         case CONSTRAINT_MEMORY_POLICY:
-                oom_kill_process(current, gfp_mask, order, points, NULL,
+                oom_kill_process(current, gfp_mask, order, 0, NULL,
                                 "No available memory (MPOL_BIND)");
                 break;
 
@@ -553,35 +614,10 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
                         panic("out of memory. panic_on_oom is selected\n");
                 /* Fall-through */
         case CONSTRAINT_CPUSET:
-                if (sysctl_oom_kill_allocating_task) {
-                        oom_kill_process(current, gfp_mask, order, points, NULL,
-                                        "Out of memory (oom_kill_allocating_task)");
-                        break;
-                }
-retry:
-                /*
-                 * Rambo mode: Shoot down a process and hope it solves whatever
-                 * issues we may have.
-                 */
-                p = select_bad_process(&points, NULL);
-
-                if (PTR_ERR(p) == -1UL)
-                        goto out;
-
-                /* Found nothing?!?! Either we hang forever, or we panic. */
-                if (!p) {
-                        read_unlock(&tasklist_lock);
-                        panic("Out of memory and no killable processes...\n");
-                }
-
-                if (oom_kill_process(p, gfp_mask, order, points, NULL,
-                                     "Out of memory"))
-                        goto retry;
-
+                __out_of_memory(gfp_mask, order);
                 break;
         }
 
-out:
         read_unlock(&tasklist_lock);
 
         /*