Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752529Ab2HTAJp (ORCPT ); Sun, 19 Aug 2012 20:09:45 -0400 Received: from mail-vb0-f46.google.com ([209.85.212.46]:52396 "EHLO mail-vb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751787Ab2HTAJn (ORCPT ); Sun, 19 Aug 2012 20:09:43 -0400 MIME-Version: 1.0 In-Reply-To: <20120819021757.GB16796@localhost> References: <1345283361-7802-1-git-send-email-linkinjeon@gmail.com> <20120819021757.GB16796@localhost> Date: Mon, 20 Aug 2012 09:09:42 +0900 Message-ID: Subject: Re: [PATCH 2/3] writeback: fix incorrect return value type of bdi_dirty_limit From: Namjae Jeon To: Fengguang Wu Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1373 Lines: 46 2012/8/19, Fengguang Wu : > On Sat, Aug 18, 2012 at 05:49:21AM -0400, Namjae Jeon wrote: >> unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long >> dirty) >> >> Above function return type is unsigned long, but return value is >> kept in "u64 bdi_dirty". >> It can return incorrect value by type casting. > > I don't see how the cast can return wrong value. > The u64 is necessary for the intermediate calculations. > > Thanks, > Fengguang Hi Wu. I understand. Thanks for your reply. > >> Signed-off-by: Namjae Jeon >> --- >> 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 49133b6..73a7a06 100644 >> --- a/mm/page-writeback.c >> +++ b/mm/page-writeback.c >> @@ -546,7 +546,7 @@ static unsigned long hard_dirty_limit(unsigned long >> thresh) >> */ >> unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long >> dirty) >> { >> - u64 bdi_dirty; >> + unsigned long bdi_dirty; >> long numerator, denominator; >> >> /* >> -- >> 1.7.9.5 > -- 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/