From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933803Ab3LIPge (ORCPT ); Mon, 9 Dec 2013 10:36:34 -0500 Received: from mail-ob0-f179.google.com ([209.85.214.179]:60927 "EHLO mail-ob0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752124Ab3LIPgd (ORCPT ); Mon, 9 Dec 2013 10:36:33 -0500 Date: Mon, 9 Dec 2013 09:36:26 -0600 From: Seth Jennings To: Chen Gang Cc: Seth Jennings , linux-mm@kvack.org, "linux-kernel@vger.kernel.org" , James Hogan Subject: Re: [PATCH] mm/zswap.c: add BUG() for default case in zswap_writeback_entry() Message-ID: <20131209153626.GA3752@cerebellum.variantweb.net> References: <52A53024.9090701@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52A53024.9090701@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 09, 2013 at 10:51:16AM +0800, Chen Gang wrote: > Recommend to add default case to avoid compiler's warning, although at > present, the original implementation is still correct. > > The related warning (with allmodconfig for metag): > > CC mm/zswap.o > mm/zswap.c: In function 'zswap_writeback_entry': > mm/zswap.c:537: warning: 'ret' may be used uninitialized in this function > > > Signed-off-by: Chen Gang > --- > mm/zswap.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/mm/zswap.c b/mm/zswap.c > index 5a63f78..bfd1807 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -585,6 +585,8 @@ static int zswap_writeback_entry(struct zbud_pool *pool, unsigned long handle) > > /* page is up to date */ > SetPageUptodate(page); > + default: > + BUG(); Typically, the way you want to address this is initialize ret to 0 at declaration time if not every control path will set that value. Seth > } > > /* move it to the tail of the inactive list after end_writeback */ > -- > 1.7.7.6 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org