mm/huge_memory.c: minor lock simplification in __khugepaged_exit
Chris Wright [Tue, 26 Jul 2011 00:12:14 +0000 (17:12 -0700)]
The lock is released first thing in all three branches.  Simplify this by
unconditionally releasing lock and remove else clause which was only there
to be sure lock was released.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c

index 81532f2..e2d1587 100644 (file)
@@ -1596,14 +1596,13 @@ void __khugepaged_exit(struct mm_struct *mm)
                list_del(&mm_slot->mm_node);
                free = 1;
        }
+       spin_unlock(&khugepaged_mm_lock);
 
        if (free) {
-               spin_unlock(&khugepaged_mm_lock);
                clear_bit(MMF_VM_HUGEPAGE, &mm->flags);
                free_mm_slot(mm_slot);
                mmdrop(mm);
        } else if (mm_slot) {
-               spin_unlock(&khugepaged_mm_lock);
                /*
                 * This is required to serialize against
                 * khugepaged_test_exit() (which is guaranteed to run
@@ -1614,8 +1613,7 @@ void __khugepaged_exit(struct mm_struct *mm)
                 */
                down_write(&mm->mmap_sem);
                up_write(&mm->mmap_sem);
-       } else
-               spin_unlock(&khugepaged_mm_lock);
+       }
 }
 
 static void release_pte_page(struct page *page)