Merge branch 'core/percpu' into stackprotector

[linux-2.6-omap-h63xx.git] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index e69edc74aeebbebc92abcb45f722e35ddc3b6667..2a803c28df9e6ed8e6dbaa6cd5d57f23c8367ba8 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -642,35 +642,31 @@ retry:
        /*
         * We found no owner yet mm_users > 1: this implies that we are
         * most likely racing with swapoff (try_to_unuse()) or /proc or
-        * ptrace or page migration (get_task_mm()).  Mark owner as NULL,
-        * so that subsystems can understand the callback and take action.
+        * ptrace or page migration (get_task_mm()).  Mark owner as NULL.
         */
-       down_write(&mm->mmap_sem);
-       cgroup_mm_owner_callbacks(mm->owner, NULL);
        mm->owner = NULL;
-       up_write(&mm->mmap_sem);
        return;
 
 assign_new_owner:
        BUG_ON(c == p);
        get_task_struct(c);
-       read_unlock(&tasklist_lock);
-       down_write(&mm->mmap_sem);
        /*
         * The task_lock protects c->mm from changing.
         * We always want mm->owner->mm == mm
         */
        task_lock(c);
+       /*
+        * Delay read_unlock() till we have the task_lock()
+        * to ensure that c does not slip away underneath us
+        */
+       read_unlock(&tasklist_lock);
        if (c->mm != mm) {
                task_unlock(c);
-               up_write(&mm->mmap_sem);
                put_task_struct(c);
                goto retry;
        }
-       cgroup_mm_owner_callbacks(mm->owner, c);
        mm->owner = c;
        task_unlock(c);
-       up_write(&mm->mmap_sem);
        put_task_struct(c);
 }
 #endif /* CONFIG_MM_OWNER */
@@ -1052,10 +1048,7 @@ NORET_TYPE void do_exit(long code)
                                preempt_count());
 
        acct_update_integrals(tsk);
-       if (tsk->mm) {
-               update_hiwater_rss(tsk->mm);
-               update_hiwater_vm(tsk->mm);
-       }
+
        group_dead = atomic_dec_and_test(&tsk->signal->live);
        if (group_dead) {
                hrtimer_cancel(&tsk->signal->real_timer);