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.
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx>
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2c90357..ce726eb 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1542,7 +1542,7 @@ 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, m_thresh = 0, m_bg_thresh = 0;
/*
* Unstable writes are a feature of certain networked
--
2.0.2
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>