Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / mm / oom_kill.c

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 7dcca55..6a819d1 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -31,6 +31,7 @@
 #include <linux/memcontrol.h>
 #include <linux/mempolicy.h>
 #include <linux/security.h>
+#include <linux/ptrace.h>
 
 int sysctl_panic_on_oom;
 int sysctl_oom_kill_allocating_task;
@@ -292,13 +293,15 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
                unsigned long totalpages, struct mem_cgroup *mem,
                const nodemask_t *nodemask)
 {
-       struct task_struct *p;
+       struct task_struct *g, *p;
        struct task_struct *chosen = NULL;
        *ppoints = 0;
 
-       for_each_process(p) {
+       do_each_thread(g, p) {
                unsigned int points;
 
+               if (!p->mm)
+                       continue;
                if (oom_unkillable_task(p, mem, nodemask))
                        continue;
 
@@ -314,22 +317,29 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
                if (test_tsk_thread_flag(p, TIF_MEMDIE))
                        return ERR_PTR(-1UL);
 
-               /*
-                * This is in the process of releasing memory so wait for it
-                * to finish before killing some other task by mistake.
-                *
-                * However, if p is the current task, we allow the 'kill' to
-                * go ahead if it is exiting: this will simply set TIF_MEMDIE,
-                * which will allow it to gain access to memory reserves in
-                * the process of exiting and releasing its resources.
-                * Otherwise we could get an easy OOM deadlock.
-                */
-               if (thread_group_empty(p) && (p->flags & PF_EXITING) && p->mm) {
-                       if (p != current)
-                               return ERR_PTR(-1UL);
-
-                       chosen = p;
-                       *ppoints = 1000;
+               if (p->flags & PF_EXITING) {
+                       /*
+                        * If p is the current task and is in the process of
+                        * releasing memory, we allow the "kill" to set
+                        * TIF_MEMDIE, which will allow it to gain access to
+                        * memory reserves.  Otherwise, it may stall forever.
+                        *
+                        * The loop isn't broken here, however, in case other
+                        * threads are found to have already been oom killed.
+                        */
+                       if (p == current) {
+                               chosen = p;
+                               *ppoints = 1000;
+                       } else {
+                               /*
+                                * If this task is not being ptraced on exit,
+                                * then wait for it to finish before killing
+                                * some other task unnecessarily.
+                                */
+                               if (!(task_ptrace(p->group_leader) &
+                                                       PT_TRACE_EXIT))
+                                       return ERR_PTR(-1UL);
+                       }
                }
 
                points = oom_badness(p, mem, nodemask, totalpages);
@@ -337,7 +347,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
                        chosen = p;
                        *ppoints = points;
                }
-       }
+       } while_each_thread(g, p);
 
        return chosen;
 }
@@ -396,7 +406,7 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
        task_unlock(current);
        dump_stack();
        mem_cgroup_print_oom_info(mem, p);
-       show_mem();
+       show_mem(SHOW_MEM_FILTER_NODES);
        if (sysctl_oom_dump_tasks)
                dump_tasks(mem, nodemask);
 }
@@ -491,6 +501,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
                list_for_each_entry(child, &t->children, sibling) {
                        unsigned int child_points;
 
+                       if (child->mm == p->mm)
+                               continue;
                        /*
                         * oom_badness() returns 0 if the thread is unkillable
                         */
@@ -537,6 +549,17 @@ void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
        unsigned int points = 0;
        struct task_struct *p;
 
+       /*
+        * If current has a pending SIGKILL, then automatically select it.  The
+        * goal is to allow it to allocate so that it may quickly exit and free
+        * its memory.
+        */
+       if (fatal_signal_pending(current)) {
+               set_thread_flag(TIF_MEMDIE);
+               boost_dying_task_prio(current, NULL);
+               return;
+       }
+
        check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, 0, NULL);
        limit = mem_cgroup_get_limit(mem) >> PAGE_SHIFT;
        read_lock(&tasklist_lock);