Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754443AbbKMSpa (ORCPT ); Fri, 13 Nov 2015 13:45:30 -0500 Received: from mail-pa0-f41.google.com ([209.85.220.41]:33259 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751934AbbKMSp3 (ORCPT ); Fri, 13 Nov 2015 13:45:29 -0500 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1659 Lines: 44 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(-) 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 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/