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| author | Yang Shi <yang.shi@linaro.org> | 2015-11-20 15:57:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-20 16:17:32 -0800 |
| commit | 50e55bf626ad3ebbca45c0c0d03eb1710a139638 (patch) | |
| tree | c5ec9ea7b3b7c16e9ddf6af986e095c2b5bb5e8e | |
| parent | 1a47de6e4a8dc2aaf3c3fb544b60730b74abe0f1 (diff) | |
| download | linux-50e55bf626ad3ebbca45c0c0d03eb1710a139638.tar.bz2 | |
mm/page-writeback.c: initialize m_dirty to avoid compile warning
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: Yang Shi <yang.shi@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/page-writeback.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 2c90357c34ea..3e4d65445fa7 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1542,7 +1542,9 @@ static void balance_dirty_pages(struct address_space *mapping, for (;;) { unsigned long now = jiffies; unsigned long dirty, thresh, bg_thresh; - unsigned long m_dirty, m_thresh, m_bg_thresh; + unsigned long m_dirty = 0; /* stop bogus uninit warnings */ + unsigned long m_thresh = 0; + unsigned long m_bg_thresh = 0; /* * Unstable writes are a feature of certain networked |