MIPS: Fix always CONFIG_LOONGSON_UART_BASE=y

[mv-sheeva.git] / mm / oom_kill.c

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 4029583a10241aaa84e3937ee216740e0a88a363..7dcca55ede7ca1493df615af994f6ba23c1bb129 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -162,10 +162,11 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
                return 0;
 
        /*
-        * Shortcut check for OOM_SCORE_ADJ_MIN so the entire heuristic doesn't
-        * need to be executed for something that cannot be killed.
+        * 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 (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+       if (atomic_read(&p->mm->oom_disable_count)) {
                task_unlock(p);
                return 0;
        }
@@ -403,16 +404,40 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
 #define K(x) ((x) << (PAGE_SHIFT-10))
 static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
 {
+       struct task_struct *q;
+       struct mm_struct *mm;
+
        p = find_lock_task_mm(p);
        if (!p)
                return 1;
 
+       /* mm cannot be safely dereferenced after task_unlock(p) */
+       mm = p->mm;
+
        pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB\n",
                task_pid_nr(p), p->comm, K(p->mm->total_vm),
                K(get_mm_counter(p->mm, MM_ANONPAGES)),
                K(get_mm_counter(p->mm, MM_FILEPAGES)));
        task_unlock(p);
 
+       /*
+        * Kill all 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
+        * task cannot exit because it requires the semaphore and its contended
+        * by another thread trying to allocate memory itself.  That thread will
+        * now get access to memory reserves since it has a pending fatal
+        * signal.
+        */
+       for_each_process(q)
+               if (q->mm == mm && !same_thread_group(q, p)) {
+                       task_lock(q);   /* Protect ->comm from prctl() */
+                       pr_err("Kill process %d (%s) sharing same memory\n",
+                               task_pid_nr(q), q->comm);
+                       task_unlock(q);
+                       force_sig(SIGKILL, q);
+               }
 
        set_tsk_thread_flag(p, TIF_MEMDIE);
        force_sig(SIGKILL, p);
@@ -680,7 +705,7 @@ 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->signal->oom_adj != OOM_DISABLE)) {
+           current->mm && !atomic_read(&current->mm->oom_disable_count)) {
                /*
                 * oom_kill_process() needs tasklist_lock held.  If it returns
                 * non-zero, current could not be killed so we must fallback to