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[147.11.216.82]) by smtp.gmail.com with ESMTPSA id vg7sm3674641pbc.2.2015.11.13.10.45.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Nov 2015 10:45:28 -0800 (PST) From: Yang Shi To: akpm@linux-foundation.org, tj@kernel.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linaro-kernel@lists.linaro.org, yang.shi@linaro.org Subject: [PATCH] writeback: initialize m_dirty to avoid compile warning Date: Fri, 13 Nov 2015 10:26:41 -0800 Message-Id: <1447439201-32009-1-git-send-email-yang.shi@linaro.org> X-Mailer: git-send-email 2.0.2 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- mm/page-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ 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