• Yang Shi's avatar
    mm/page-writeback.c: initialize m_dirty to avoid compile warning · 50e55bf6
    Yang Shi authored
    When building kernel with gcc 5.2, the below warning is raised:
    
      mm/page-writeback.c: In function 'balance_dirty_pages.isra.10':
      mm/page-writeback.c:1545:17: warning: 'm_dirty' may be used uninitialized in this function [-Wmaybe-uninitialized]
         unsigned long m_dirty, m_thresh, m_bg_thresh;
    
    The m_dirty{thresh, bg_thresh} are initialized in the block of "if
    (mdtc)", so if mdts is null, they won't be initialized before being used.
    Initialize m_dirty to zero, also initialize m_thresh and m_bg_thresh to
    keep consistency.
    
    They are used later by if condition: !mdtc || m_dirty <=
    dirty_freerun_ceiling(m_thresh, m_bg_thresh)
    
    If mdtc is null, dirty_freerun_ceiling will not be called at all, so the
    initialization will not change any behavior other than just ceasing the
    compile warning.
    
    (akpm: the patch actually reduces .text size by ~20 bytes on gcc-4.x.y)
    
    [akpm@linux-foundation.org: add comment]
    Signed-off-by: default avatarYang Shi <yang.shi@linaro.org>
    Cc: Tejun Heo <tj@kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    50e55bf6
page-writeback.c 83.7 KB