The patch titled
Subject: mm/page-writeback.c: initialize m_dirty to avoid compile warning
has been removed from the -mm tree. Its filename was
writeback-initialize-m_dirty-to-avoid-compile-warning.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Yang Shi <yang.shi@xxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxxxxxxx: add comment]
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN mm/page-writeback.c~writeback-initialize-m_dirty-to-avoid-compile-warning mm/page-writeback.c
--- a/mm/page-writeback.c~writeback-initialize-m_dirty-to-avoid-compile-warning
+++ a/mm/page-writeback.c
@@ -1542,7 +1542,9 @@ static void balance_dirty_pages(struct a
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
_
Patches currently in -mm which might be from yang.shi@xxxxxxxxxx are
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
